Regional Rail and Subway Maintenance

Uday Schultz has a thorough post about New York’s subway service deterioration over the last decade, explaining it in terms of ever more generous maintenance slowdowns. He brings up track closures for renewal as a typical European practice, citing examples like Munich’s two annual weekends of S-Bahn outage and Paris’s summertime line closures. But there’s a key aspect he neglects: over here, the combination of regional rail and subway tunnels means that different trunk lines can substitute for one another. This makes long-term closures massively less painful and expensive.

S-Bahn and subway redundancy

S-Bahn or RER systems are not built to be redundant with the metro. Quite to the contrary, the aim is to provide service the metro doesn’t, whether it’s to different areas (typically farther out in the suburbs) or, in the case of the RER A in Paris, express overlay next to the local subway. The RER and Métro work as a combined urban rail network in Paris, as do the S- and U-Bahns in German cities that have both, or the Metro and Cercanías in Madrid and Barcelona.

And yet, in large urban rail systems, there’s always redundancy, more than planners think or intend. The cleanest example of this is that in Paris, the RER A is an express version of Métro Line 1: all RER A stops in the city have transfers to M1 with the exception of Auber, which isn’t too far away and has ample if annoying north-south transfers to the Champs-Elysées stations on M1. As a result, summertime closures on the RER A when I lived in the city were tolerable, because I could just take M1 and tolerate moderate slowdowns.

This is the case even in systems designed around never shutting down, like Tokyo. Japan, as Uday notes, doesn’t do unexpected closures – the Yamanote Line went decades with only the usual nighttime maintenance windows. But the Yamanote Line is highly redundant: it’s a four-track line, and it is paralleled at short distance by the Fukutoshin Line. A large city will invariably generate very thick travel markets, and those will have multiple lines, like the east-west axis of M1 and the RER A, the two north-south axes of M12 and M13 and of M4 and the RER B, the east-west spine from Berlin Hauptbahnhof east, the Ikebukuro-Shibuya corridor, or the mass of lines passing through Central Tokyo going northeast-southwest.

The issue of replacement service

In the United States, standard practice is that every time a subway line is shut for maintenance, there are replacement buses. The buses are expensive to run: they are slow and low-capacity, and often work off the overtime economy of unionized labor; their operating costs count as part of the capital costs of construction projects. Uday moreover points out that doing long-term closures in New York on the model of so many large European cities would stress the capacity of buses in terms of fleet and drivers, raising costs further.

This is where parallel rail lines come in. In some cases, these can be other subway lines: from north of Grand Central to Harlem-125th, the local 6 and express 4/5 tracks are on different levels, so the express tracks can be shut down overnight for free, and then during maintenance surges the local tracks can be shut and passengers told to ride express trains or Second Avenue Subway. On the West Side, the 1/2/3 and the A/B/C/D are close enough to substitute for each other.

But in Queens and parts of the Bronx, leveraging commuter rail is valuable. The E/F and the LIRR are close enough to substitute for each other; the Port Washington Branch can, to some extent, substitute for the 7; the Metro-North trunk plus east-west buses would beat any interrupted north-south subway and would even beat the subway in normal service to Grand Central.

Running better commuter rail

The use of commuter rail as a subway substitute, so common in this part of the world, requires New York to run service along the same paradigm that this part of the world does. Over here, the purpose of commuter rail is to run urban rail service without needing to build greenfield tunnels in the suburbs. The fares are the same, and the frequency within the city is high all day every day. It runs like the subway, grading into lower-density service the farther one goes; it exists to extend the city and its infrastructure outward into the suburbs.

This way, a coordinated urban rail system works the best. Where lines do not overlap, passengers can take whichever is closest. Where they do, as is so common in city center, disruption on one trunk is less painful because passengers can take the other. The system does not need an external infusion of special service via transportation-of-last-resort shuttle buses, and costs are easier to keep under control.

99 comments

  1. Frederick

    There are three obstructions to such a plan:

    1. Fare. Currently there is a surcharge when you take a Metro-North/LIRR train from the suburb to fare zone 1. I don’t know what’s the original reason for this (maybe it’s to deter Outer Borough dwellers from boarding an inbound train, maybe it harks back to the time where most Manhattan crossings were tolled) but this is stupid and needs to stop. At least, it makes a trip to Manhattan much more expensive than a similar trip using the subway, thus making it an unsuitable substitute of the subway.

    2. Station density. The MN/LIRR has shockingly few stations inside NYC. Woodside is 3 miles away from Penn station. 125th St is 4 miles from Grand Central. That means they cover a much smaller area than the subway.

    3. Efficiency. Can the MN/LIRR operate with the frequency of the subway? Can they transport as many people in one hour as the subway? And also, they are not that much faster than the subway: Fordham to Grand Central takes 24 minutes on the suburban rail, but the subway takes 27 minutes, just 3 minutes more.

    • Eric2

      2. That can, and should, be addressed by bustitution IN ADDITION to regional rail substitution. Those who need local service can take the bus, those who want express service can take the regional rail. Some buses will be needed, but many fewer than with bustitution alone.

    • crazytrainmatt

      You make some good points:
      1) There have been complaints from city politicians about the commuter railroad fare structure for decades. The suburbs don’t want to give an inch but operating expenses might force the issue once the bailout ends. If the white-collar return to office continues to stretch out, I could easily see the politics finally coming together to reduce in-city fares. The restriction on using New Haven trains to between Manhattan and Fordham was finally dropped a few years ago, fare adjustment would make a huge difference in transit accessibility of that area.

      2) There is a lot more employment and housing in LIC these days. Sunnyside isn’t perfectly located but it would certainly help!

      3) This is by memory, but Fordham-Grand Central used to be scheduled at under 20 minutes a decade ago. Even this included the slow crawl through the station throat. The larger point is that the commuter railroads have plenty of room for increased efficiency. Removing the third seat would be a no-brainer for capacity concerns.

      • bruce hain

        @crazytrainmatt – It’s more annoying when you consider the instant station throat was designed for speed. Penn’s Summer of Hell surprisingly resulted – nonetheless – in deformations visible from the train window at Interlocking A that take like a decade to get that way. In an optimum world (with at-least passing-ok people overseeing these construction/”state-of-good-repair” projects, and scheduling to keep up with the needed work) I would still see the commuter lines as a premium fast service that justifies an extra fare. Not to say using it when the subway is out somewhere closeby couldn’t be undertaken WITHOUT the extra fare, but capacity and scheduling must be considered. I don’t think it’s optimum to have it on a permanent basis.

        The subway line closures, with the trains running on the one line called by the names of ones that run on a different line, is a relatively recent thing, that arose relative to a scandalous number of track crew fatalities back in the day. The proprietors seemed incapable of scheduling and overseeing it safely, as they apparently had since the beginning theretofore, while the union objected to the carnage. At this point it doesn’t seem likely that status quo ante scheduling can ever be restored, but they used to do it in such a way that nothing was ever shut down except briefly at night. The proprietors make a lot out of union rules to justify a lot of things.

        • bruce hain

          The business with the station throat is like the propaganda kinks elsewhere, notably on the LIRR opposite Sunnyside Yard for like a decade, to give us a clear impression of how trying these projects are for both the overseers and contractors – always changing their minds about things – and that we’re lucky they aren’t charging us still more for it. There was a big one on the inbound A from Brooklyn for a few years, right in the middle of the subaqueous tube. After the initial weeks of FRIGHT for both passengers and motormen no doubt, it became just a nuisance having to suffer the slow-to-crawl every day when you were in a hurry. Propaganda Kinks were invented by the PRR, to discourage passengers on their NEC property back in the Sixties.

          • bruce hain

            The US has a great tradition of railroading improprieties. The business at Sunnyside involves also constant rearranging of special trackwork in the area (vaguely) of the East Side Access Project. I think their goal is to get all told a $million per linear foot out of some of it.

    • Union Tpke

      Re:1, I can’t share the document, but it specifically states that fares are high in Inner New Jersey and NYC as the commuter rail systems are intended to primarily serve the suburbs and as existing systems are capacity-constrained.

    • Phake Nick

      On station density. In places where commuter rail matures, even if station are farapart, those stations in themselves are often core of some local business/employmeny/commercial area and also provide convenient interchange to other more local mode for less popular places nearby, hence three or four mile station spacing isn’t really a problem. Although obviously one can also add extra stations in between if desired.

      • Henry Miller

        Although you can, I’m not sure you should. The farther apart the stations are the faster the trains can go. Thus your infill stations reduce speed for those who don’t want to go to them, unless they run on separate tracks. If you have enough demand to support four tracks (or more), then by all means run express and local service it. I think most cities are better off with a radial bus system from each of the farther apart stations. This allows locals to access services near the station quickly (15 minutes in the worst case), or get a train to elsewhere for the odd things that can’t support being near every single station.

        Of course there are exceptions. If you have a major destination that ends up not at a current station then by all means add the infill station. However for all situations you need to consider if the compromise to everyone is worth the convenience for those who would use the station.

  2. Union Tpke

    I have thought about this for some time. To allow for switch installation work at 75th Avenue, during every weekend in July 2017, and the first weekend of August 2017, there was no E and F service east of Forest Hills (http://web.archive.org/web/20170710161334/http://web.mta.info/nyct/service/planned_servChanges_EF_weekend.htm). There was EXTENSIVE shuttle bus service, but there was also cross-honoring via the LIRR. This, however, led to crowding on the LIRR. The LIRR currently doesn’t have the capability of accommodating these increased loads as Uday noted here (https://twitter.com/A320Lga/status/1416121418157371398).

    • Eric2

      He doesn’t note that LIRR cannot take the loads, he notes that he doesn’t know if LIRR can take the loads.

      In reality, particularly on weekends when commute loads are much lower, there should be spare capacity for a large fraction of the subway riders.

    • Alon Levy

      I don’t think Uday is correct on this. Per the Hub Bound reports, the LIRR and Metro-North are both roomy by subway standards. The average rush hour train has about as many passengers as a subway train, but LIRR trains are about twice the size, and the average train (not the average passenger) has empty seats even at rush hour.

      The perception that the LIRR and Metro-North are at capacity come from an entitled set of riders who think “the middle seats get filled” means the train is at capacity, but by city standards it’s nothing.

      • adirondacker12800

        LIRR trains are about twice the size
        12 car trains may have twice the seats but they aren’t twice the size. They don’t run all services with 12 cars trains either.
        entitled set of riders
        Who pay very high fares. Who aren’t as masochistic as you.

        • Sassy

          If they don’t want people in the middle seat, they should pay even higher fares, and we can attach some 2+2 reserved seating cars. The entitled rich folk can pay more cheaper tickets and more frequent service, for people who aren’t afraid to sit sideways or even make use of their legs (“masochists” in entitled rich folk terminology).

          • adirondacker12800

            a lot of them use their legs, on the LIRR and NJTransit anyway, for the first part of their commute home because rush hour trains have standees. And non rush hour trains if you get unlucky.

          • Alon Levy

            NJTransit trains have standees; LIRR ones usually don’t, and rarely do east of Jamaica.

            The LIRR averages 10.5-car trains, I believe? So, around 263 meters by 3.2, vs. 180 by 3 on the subway. Not 2x unless it’s 12 cars, but still 1.5x with somewhat fewer passengers per train.

          • adirondacker12800

            I don’t remember how many times I rode to Woodside for free because the train was too crowded for conductors to wade through. The subways you want the LIRR to supplement are west of Jamaica.
            When there are 8 tracks of railroad some of the trains can stop every ten blocks, some of them every 30 or so, some of them in a few places and some of them not at all. It’s too bad it’s not a red line and blue line.

      • uday schultz

        Yeah, but room available isn’t the only important quantity here. I was thinking more about the dwell time (=capacity, speed) implications of a significant increase in loads on the LIRR *within current network infrastructure constraints.* Youd have a much better shot at handling this in a RR’ed world, but the time period of concern in the linked tweet was QBL CBTC.

        • fjod

          But you tend not to be doing maintenance during the rush hour, so dwell time shouldn’t be an issue. That is unless dwell time is scheduled to vary by time of day – but then you can just tweak schedules to run trains as you would at rush hour instead, and the issue goes away.

          • uday schultz

            Yes, but that’s the time period my original point about service resource constraints was about!

  3. borners

    I’m guessing this is another argument for building orbitals, where I live in Chiba I have access two 1 seat rides to Tokyo via the Joban and Musashino lines (which is primarily orbital but about half its services use the Keiyo to get to Tokyo station). The latter is indirect and longer while being a longer by 10 minutes walk but I have used it when there have been delays.

    I’d also wondering about improving redundancy in London, there is no low-hanging fruit like the LIRR and as you’ve said in other related posts its hard in London because the tunnels don’t parallel to share track like in New York Express tracks or Copenhagen. But a bunch of Tube lines parallel outside the tunnels especially in Northwest London especially the Jubilee, Metropolitan and Bakerloo.

    • Eric2

      An orbital is less valuable than a radial, it will get lower ridership. Similarly it’s not worth building lines for redundancy, it is rare they will be used for that purpose, and when they are buses could do a tolerable job for much less money.

      London actually does have low-hanging fruit: the Overground can be upgraded to higher frequencies and better Underground connections. It wouldn’t be worth building an Overground from scratch, but it’s worth upgrading it.

      • borners

        True enough, you actually need a large radial network to justify building orbital systems e.g. Berlin to Tokyo scale. And as far as I’m aware all the heavy rail orbital circuits outside of China were originally freight bypasses converted to passenger service; the Ring in Berlin, the Musashino-Nambu in Tokyo and of course London’s outer loop now Overground. Makes one think about where to draw the line between a piecemeal light-rail orbital strategy (Paris, London) or a heavy rail circle strategy (Tokyo, Beijing), simply a matter of size/potential ridership?

        You’re right that overground has low-hanging fruit but compare to LIRR? With much knarlier set of legacy lines! Hopefully giving the lines proper names and colors will help people understand how crap the missed connections are better.

        • Phake Nick

          Even at Tokyo scale, they keep failing to justify the construction of a new orbital line along Kannana/Kanhachi road.
          Taipei have been building an orbital line but their ridership also appears to be kinda low. On the other hand Moscow seems to have quite successful orbital lines?

          • borners

            Tokyo has 4 layers of orbital, Yamanote, Musashino-Nambu and Tobu Noda/Kawagoe/Sagami layers are considered successful. And the Oedo was somewhat screwed up but its Tokyo so there is ridership. And partial orbitals like the Shinkeisei or the Tama monorail/tram do fine.

            And they should definitely not do those two projects, they should still build more line in the Tokyo area but it should be extensions of the Keiyo/Tsukuba express plus something to relieve the ultra busy Tozai/Shinjuku lines east of the CBD. Also stuff to bridge the big gaps in Kanagawa’s network between the Odakyu-Keio areas and the main Yokohama-Kawasaki nexus.

            And Osaka is still building out the Osaka monorail which is its second layer of orbital, they really screwed themselves building monorail but still worth doing.

          • Phake Nick

            @borners Wouldn’t the extension of Yokohama subway also help with Tokyo in term of Orbital?
            But the problem with these existing orbitals, is that while Oedo line and Yamanote line offer orbital connection around the center of Tokyo, the other orbital lines mentioned are mostly really just about connecting different suburbs/exurbs together, and there’s a pretty big gap between those outer orbitals and inner loops, and by coming up with the idea of Kannana/Kanhachi rail, they want to connect the outskirts of Tokyo together so that people don’t need to either get into the city or move out to like Tachikawa in order to reach another outskirts part of Tokyo metro area

        • Nilo

          Paris Lines 2/6 were and the GPX will have been purpose built rapid transit systems!

        • Richard Gadsden

          Paris, of course, had orbital lines – petit ceinture (now closed) and grand ceinture (now mostly a freight bypass), but they’re no longer used by passenger services.

          • Herbert

            The question is: why?

            The ring is probably Berlin’s most important S-Bahn line and it was in a state of disrepair some twenty years ago…

          • michaelrjames

            @Herbert: “The question is: why?” (why did the PC fall into disuse).

            It was a combination of things. Unlike the new Metro (1900) which was all-electric the PC remained steam-driven. Of course the Metro was a state project while the PC was privately owned (by the five companies that owned the mainline train stations), and not nationalised until 1938 which was after the companies had themselves abandoned the line (last pax 1934) replaced by their PC bus service on the Boulevards Marechaux instead. They had failed to invest in the line for most of the century, and the Grand Ceinture had taken over goods transport. In the 1950s the bridges that carried it across the Seine were demolished and replaced with road bridges (eg. current Pont Garigliano, though I think it still goes over the Seine on Pont National at Bercy probably still servicing industry on both sides into the 80s, ie. Bercy and eastern 13th below Austerlitz; all of that has disappeared since I first lived in Paris in the 80s!), and I suppose the state was more focussed on its road projects then, ie. building the Peripherique and linking all the Autoroutes. The Ligne Auteil (from St Lazare to Auteil in the 16th) which carried passengers from 1954 until 1934, and IMO predates London’s Metropolitan line by almost a decade as contender for world’s first* Metro, was taken in 1985-1988 for the RER-C1-C3 northern branch (ie. the one that crosses the Seine on viaduct over the Allee des Cygnes now Île aux Cygnes).

            Alon says that its route (several blocks back from the Boulevards Marechaux) and lack of stations making easy connections to the Metro was a factor in it not being integrated, and I suppose why the RATP and the state weren’t interested in buying it from the private companies. As mentioned by others London’s Overland has this same problem today, ie. less than ideal connections to the main LU network. It usually comes down to budgets and priorities of where to spend.

            It seems like it slipped between the cracks of history. And today its future lies in the enthusiasm of history buffs who want the remaining bits: about continuous 25km from rive gauche in the 15th anti-clockwise to Batignolles (now Martin Luther King park) in the 17th. One can see it as a kind of trenched Promenade Plantée (or High Line). They need to get it UNESCO listed or something similar and find a budget from that somehow because RATP won’t want to spend their budget on it.
            …………………..
            *but because both the Ligne Auteil and the Metropolitan Railway were steam-driven and trenched (mostly open, to cope with the appalling pollution from those locomotives), the real ‘world’s first Metro’ was what is known as today’s Northern Line which opened in 1890 using electric traction and deep-bored tubes. The Metropolitan line didn’t go electric until 1910 and by then the original trenched line and its stations were not used for what we know today as the Metropolitan line. So, for perhaps similar reasons, both the early forerunners of modern Metro were lost, though part of the Auteil line can be experienced by riding RER C1, C3.
            Here’s my earlier post on this:
            https://pedestrianobservations.com/2019/01/25/the-soviet-bloc-way-of-building-rapid-transit/#comment-42140

          • fjod

            Probably a combination of the périphérique fulfilling the same function, and the much more centre-focussed geography of the wider Paris urban area (within the city, metro lines like lines 2 and 6 do this) compared to Berlin. Of course, they are building GPX.

      • Matthew Hutton

        The main thing the overground needs is more connections to the mainlines where it crosses them.

    • Frederick

      There is also the very little known Acton-Northolt line runs parallel to the Central line between West Ruislip and North Acton.

    • Frederick

      There is also the very little known Acton-Northolt line that runs parallel to the Central line between West Ruislip and North Acton.

  4. Phake Nick

    The quadrupled Yamanote line still need to be shut down whem incident occurs because they aren’t isolated from.each other and that even affecting Chuo line service, due to the need of evacuating passengers on trains via track, as can be seen in certain recent power failure affecting the line.

    In Hong Kong, with commuter railway effectively integrated as part of the metro network, while it can provide some redundancy, especially after the full opening of the new Tuen Ma Line and the upcoming East Rail Line Extension, replacement buses are still necessary when a metro line go down because other rail lines doesn’t have sufficient capacity to fully absorb all the passengers of the original rail line, and the somewhat-CBD-centric rail network topology also make it not always possible to reach destination through another nearby rail line.
    But then, the design of many of those rail-replacement-bus-routes, due to their nature of needing to drive right to the doorstep of each individual rail station, the journey time get extended very significantly, a trip that took a rail 5 minutes in usual time and 10-15 minutes for buses could end up costing the replacement service more than half an hour to travel making such option very much inefficient. And when accidents occurs, those replacement buses are usually also not immediately available and are at limited capacity.
    As such, when transportation department want to rework bus route according to extension of rail network, there are common sentiments against such rework even for trips where rail clearly have advantage over buses, because retaining such.kind of route mean bus companies are more likely to be able to add services onto related routes directly and send passengers directly to destinations instead of having.to wait for rail.replacement buses. But such arrangement is.obviously inefficient and thus bus companies aren’t willing to support such idea.

    Another problem with redundancy is operation under adverse weather. In Hong Kong when typhoon hit, when hurricane force wind affecting the city, the metro system will only operate the underground segment, for the safety of passengers. However, due to cost saving measures, all commuter rail lines connecting to satellite towns are constructed either on the surface or elevated outside metro area, hence cannot provide service when typhoon hit the city. While it make sense to save construction cost by reducing percentage of tunnelling and underground station, there are also criticism that such arrangement failed to meet commute need of residents in those satellite town during.typhoon, who are often poorer.

    How nuch extra should be spent on keeping such redundancies in regular times that would only get used every once in a while in extraordinary events?

    • Tonami Playman

      Yeah building rail transit redundancy seems quite wasteful, though a larger network can absorb the passengers from a line or section undergoing major maintenance. I remember the Hanzomon line acting as a relief line for the Ginza line during the Ginza line Shibuya station relocation. The Ginza line was closed between Shibuya and Omotesando for 3yrs (2016-2019) where the cross-platform interchange with the Hanzomon line allowed westbound Ginza line passengers to still reach Shibuya station.

      Tokyo’s intense network means other lines pick up the slack, though I do wonder how Osaka deals with disruptions on the Osaka loop line with its high level of interlining services.

      • Andrew in Ezo

        The Osaka Loop Line doesn’t have the level of impotance as a circulator of traffic as the Yamanote Line does in Tokyo, in fact the primary transporation artery in Osaka is the Midosuji Line subway (1.3 million pax/day), which connects the major business and commercial centers from Shin-Osaka via Umeda and Namba to Tennoji. Some of the private railway operators (Nankai, Keihan, and Kintetsu) actually have their main line terminals *within* the area of the loop, different from that of Tokyo, where the private railways situated their terminals along the Yamanote line outer edge. Since the core of Osaka is comparatively compact, I reckon with a service disruption commuters just switch to the subway to get to their destination, or take a bus.

  5. Herbert

    If I understand correctly, this blog is pro skyscraper.

    This video is an argument against skyscrapers from a pro urbanist position. What say ye?

    • Phake Nick

      Isn’t this video the one that say “We don’t need that many people in cities hence we don’t need skyscrapers”? As we can see machines are replacing human in ordinary tasks and what’s left for human to create is by connecting with other humans around the world, it’s becoming increasingly common for a city to have over 20-30 Million population, ans thus I fail to see why the video uploader wouls think his argument can be established.

      • Herbert

        In cities of twenty million, the vast majority of them do *not* live in skyscrapers…

        Maybe in Tokyo, but I think not even there…

        • Sassy

          People do more in a city than just sleep. If the plan is to never leave home, then why live in a city in the first place.

        • borners

          @Herbert definitely not even Tokyo. Its weird this guy has actually spent time in Japan. Most skyscrapers have open-to-the-public commercial space on the bottom few floor (e.g. daycare) and no parking craters. And often the newer residential ones along the major rail lines were built next to renovated high-capacity stations with shopping malls, public facilities and new parks too. Sure none of them are mega-sky=scraper in scale but who cares.
          And Dubai is a terrible example for pretty much everything.

          • borners

            He doesn’t even explore issues of maintenance and organisation which occur when you have a much more technologically complex building than a house or Euroblock, with a huge numbers of residents potentially mixed between owners and renters that create collective action problems, here’s a good discussion of the Japanese side of things, which is particular given earthquakes, high-housing turnover etc. But using 20 story building for non-elite non-cbd housing is something pioneered by Hong Kong and Japan. And HK is even more particular.
            https://catforehead.com/2019/11/16/the-further-they-fall/

            But if your building is serving the top 5% of your urban income distribution in an evergreen luxury location you can probably spend through it. That’s what Manhattan suggests. And keeping the 5% in the clouds does keep them out of ordinary residential districts.

          • Eric2

            From what I remember, there is a jump in maintenance costs when you pass ~10 stories (I’m very unsure about the exact number). But as you get higher, the costs decrease again because they are averaged over more units. Once you reach ~30 (again very unsure) stories, costs per unit are similar to a short building.

          • Herbert

            Reinforced concrete has a ticking clock measured on the scale of human lifetime.

            Materials used in midrise construction last longer.

          • Matthew Hutton

            There’s also a jump in maintenance costs when you get to 4 stories or whatever height you need lifts for as lifts are super expensive compared to stairs.

          • borners

            I’d love to see a non-polemical and rigorous comparative study of the major high-rise residential traditions in the world; New York, Japan, ROK and Hong Kong. Working through lifetime social costs etc. This a technology before its a weapon or a ideal.

          • Eric2

            “There’s also a jump in maintenance costs when you get to 4 stories or whatever height you need lifts for as lifts are super expensive compared to stairs.”

            Presumably that does not apply to new construction, which has to be all wheelchair accessible.

          • Henry Miller

            Obviously country and local specific, but often if you have 3 or less floors you can use one floor (ground level) as wheelchair accessible, and no accessibility for the other floors.

          • Nilo

            Brazil also has tons of high-rise apartment living. Though it’s confined to the middle and upper classes. It’s fine. Europeans have this strange allergy to tall buildings that as far as I can tell is all built around some sort of weird psychosis regarding Manhattan/New York’s supplanting of Paris/London/Berlin as the world’s most important city.

          • michaelrjames

            Ha, Nilo it is you who is revealing “some sort of weird psychosis”. Not only did the French pioneer reinforced concrete but the Eiffel Tower was the tallest structure in the world for 41 years, from 1889 when built until the Chrysler Building in NYC in 1930. It is taller than London’s Shard. It was twice as high as the Washington Monument built at the same time (1884). By comparison with that old-fashioned stone structure (which needed huge remedial works recently to stop it sinking into the Potomac swamp!) the Eiffel is a wonder of structural economy and lightness and aesthetics. Similar aesthetics apply to Paris which even Americans (and dare I say, Brazilians) acclaim as the most beautiful city etc etc. And a residential density that matches Manhattan.

            No, the French simply quickly realised that living in hi-rise was inferior to low-rise, both personally and of course aesthetically for the town or city. That’s why the upmarket versions eg. Front-de-Seine (Beaugrenelle, the group just downstream of the Eiffel Tower) or middle-class versions (those 31 storey towers in the 13th) or worst of all the hi-rise projects in the banlieu which had the habit of rapid deterioration, never took off. The better-built versions will persist (but see below* on the recent renovation of Beaugrenelle) but the hi-rise social housing will all be gone within the next few decades. (Onux is right about reinforced concrete but nevertheless these buildings are deteriorating fast, perhaps a combination of poor construction and even poorer maintenance. It seems strange to me but water damage is always part of the story; one would think this easy enough to avoid without great expense…) Almost all such hi-rise residential around the world has been driven by developers chasing outsized profits not the natural free choice of occupants, though I know you believe it is desired by those owners.

            La Defense shows there is no particular aversion to hi-rise per se, and it is more a question of appropriateness. It is the largest financial district in Europe and they are actually demolishing some of the hi-rise residential built on its periphery to replace with hi-rise offices to facilitate La Defense’s continuous growth.

            I’ve lived in all these situations/types and I would never choose to live in hi-rise. Unless I lived in Hong Kong or probably Brazil or NYC where I would not be rich enough to do otherwise. Security has to be a big factor in those Brazilian mega-cities along with a heliport on the roof:-)
            ………………..
            *One significant reason I dislike hi-rise (or even modern versions of low-rise) are the low-ceilings. Even the upmarket ones like Beaugrenelle have this feature which makes for a much less pleasant living experience. That can never be remediated while some of the overall design weaknesses can or may be addressed (expensively). But they rarely are which is why most hi-rise developments or districts are pretty depressing. Parts of HK (probably best in the world) or other hi-rise cities may be interesting and ‘vibrant’ but plenty of it is not.
            https://casestudies.uli.org/beaugrenelle/
            BEAUGRENELLE
            Urban Land Institute Case Study

            Beaugrenelle is part of the Front de Seine district, a multifunctional mixed-use district—a city within a city—that incorporates podiums to separate pedestrian and auto traffic. The retail center was aging both functionally and aesthetically, and became outmoded over the years and lost its appeal, in part because it was introverted and oriented away from the surrounding streets. The original stratification of activities within the larger district was out of step with current market trends, and this separation of activities is now viewed by urban designers and developers as unnecessary and actually detrimental to the urban environment.

          • borners

            Psshaw, Berlin and Paris were never that important, London overtook Edo in ca.1800 to become no.1 not Paris. And have you seen East London of late? I was surprised when I last went Greenwich and climbed the hill. Eastern Inner London is building quite a bit its the damn suburbs and shires not building enough. And we didn’t really need the office space till the 1980’s since Her Majesty’s government was so keen to remove jobs from the City 1945-1979. And they were actually experimenting 10 story plus buildings before the war (see the building on top of Baker Street station). But the damn Labour/Tories blob banned them for being too good or something.

            Less nationalistically, most major cites in Europe are not big enough that the trade-offs of forgoing skyscrapers and 10 storey plus apartment is big. Paris is the exception, but also its Paris. Also the Belgian, Dutch and Ruhr urban systems polycentricity doesn’t help. Even Japan has nimby height restrictions in Kyoto and a lesser extent Nagoya.

          • Onux

            @Herbert

            “Reinforced concrete has a ticking clock measured on the scale of human lifetime. Materials used in midrise construction last longer.”

            This statement is wrong on two counts. 1) There has been much talk recently that concrete *structures* have a 50-100 year life, but this mainly refers to outdoor structures that suffer when the rebar starts to rust (concrete is porous over time), expand, and spall away the concrete. This varies on climate; a seawall fails sooner than a desert overpass (for seawalls it is common to use fiberglass rebar now).

            Inside is different. Wood used structurally outdoors has a nominal life of 10-20 years, or 40-50 years if treated. There are however many wood homes hundreds of years old. A wood railroad tie lasts 8-25 years based on climate, a concrete tie lasts 40. In the same way, if reinforced concrete lasts 50-100 years in an outdoor overpass, then concrete inside a building (protected from rain, sun, wind, temperature changes/thermal expansion, and freeze-thaw cycles) will last quite a long time indeed.

            In fact, the oldest reinforced concrete buildings are around 120 years old and still in use (Berkeley Apartments in Buffalo, and Ingalls Bldg. in Cincinnati). Even the 50-100 year figure for outdoor works is suspect – the US is filled with thousands of culverts, viaducts, and overpasses from Interstate construction that are more than 50+ years old and still in use without mass failure. The failure of the condo tower in Miami was probably due to an improperly built and maintained roof letting water in and the building being built with less rebar than required by the plans. If reinforced concrete life really began to end at 50 years, we would see collapses every day from buildings and bridges built in the 50’s and 60’s around the globe.

            2) Reinforced concrete is one of the main materials used in midrise (4-10? stories) construction, perhaps the vast majority. Wood framing and light gauge steel don’t go much above 4-5 for structural reasons (although mass timber construction for taller buildings is making a comeback) plus many midrise wood buildings have a first floor podium of reinforced concrete anyway, masonry needs steel reinforcement above a few stories (which for cinder block means it becomes reinforced concrete too), and heavy steel (I-beams and such) is not frequently used in midrise due to cost. As always, variation due to local conditions or purpose of any given building can be high.

    • Sassy

      Regardless of your thoughts on skyscrapers, that entire video seems to be presented from a position of ignorance.

      The thumbnail image is literally of a city that has relatively few skyscrapers (per capita), literally zero of the supertalls he was complaining about, is mostly low and mid rise except in the highest density areas. And in the highest density areas, the floor area ratio is 13 (and more when developers are granted exceptions), which is physically impossible with a 10 story building on the same lot even if you disregarded geometry and sunlight laws.

      There wasn’t even enough thought/knowledge/research put in to have a good example to complain about.

      • michaelrjames

        I agree there are some failures in logic but I am not sure of your point either. Here is my summary:

        “You don’t even need to go above ten floors.”
        Skyscrapers:
        Problem #1: Environmental (heating/cooling)
        Problem #2: Cost (eg. no affordable apartments)
        Problem #3: Alienation (lack of social interaction)
        Problem #4: Logistics (facilities like schools, childcare etc)

        Contrasting examples:
        Worst case: Burj Khalifa:
        163 floors @828m tall,
        172,000 m2 residential space; 28,000 m2 office space.

        Low-Rise: Faluház/Village House, Budapest.
        10 floors, 43,500 m2 (residential)
        3000+ inhabitants in 884 apartments

        Solution: Repurpose Burj Khalifa ground space:
        Can fit 5x Village Houses
        174,000 m2 residential
        43,500 m2 office space
        …………………………
        So, his main point is that on the same footprint as the tallest (residential or anything) skyscraper in the world, you could fit five of the Faluház/Village House providing identical residential floor area (174k versus 172k m2) plus about double the amount of non-residential floor area. Of course this is exactly my point that I have made many times on Alon’s blog. It’s why inner-Paris is one of the densest residential zones in the world, and certainly over an area of ≈100km2, yet with >99.99% of buildings under 8 floors.
        He doesn’t give the number of residents of the Burj Khalifa and that’s probably because no one really knows or is saying. I don’t know its current status but in the early years they had trouble selling apartments. And doubtless, like most expensive real estate like this (including those NYC supertalls) occupancy will be low even for those sold. The alt scheme would house about 15,000 people in the same footprint compared to probably less than 1,000 in Burj Khalifa, however obviously very different apartments and price.
        I don’t think using UAE as an example is so great though it benefits his argument because Burj Khalifa’s extravagant footprint (of parks and lakes). I’m also not keen on his Faluház example, built in the 70s and the biggest building in Budapest, because such an unrelenting monotonous facade (315m long; most cities don’t allow that) and presumably gigantic long internal corridors, and its towers-in-a-park arrangement (even though low-rise) seem pretty oppressive. I understand it is a way to make his point dramatic, but I prefer to make the same points using the undeniable romance of Paris and its Haussmannian apartment buildings and streets (well the mix of Haussmannian boulevards within the dense smaller street structure).

        Some other examples of his somewhat weak logic are his Problem #4 in which he talks about the difficulty of providing schools, daycare etc in the high-rise district. In principle it doesn’t seem like it would be much different to a very dense low-rise district like Paris, except it would have to be housed in the hi-rise; and it is definitely not a problem in Paris which has a high density of such facilities. He also talks of the time taken to get anywhere from the 50th floor; and proven by those NYC supertalls which economise on elevators and thus can involve long waiting times. The Burj K has superfast elevators but they had problems in the early years causing the same problem. Even if you took the strategy of Léa Seydoux (defenestration from the hundred-whatever floor) it might still take longer than a 6-storey walkup to reach ground level!
        Also he seems to suggest with his ideal 10-floor system one wouldn’t need “expensive” transit like underground metro, but clearly that is simply wrong, both within a place like Paris or to provide access to the greater Paris; and as we know Paris has the densest transit in the world. Presumably what he is alluding to (but doesn’t say) is that it would be a very good walkable neighbourhood, which indeed Paris is, but it still needs the Metro …

        I think his problem is that he is trying to argue a bit like Alon, ie. in an econocratic fashion in which hi-rise is inefficient, but that doesn’t really work. From many p.o.v. it is more efficient. Just inhuman; and as a consequence in the real world becomes inefficient because no one wants to live there, or they trash the joint or keep throwing themselves off the 30th floor (ie. JG Ballard’s Hi-Rise) and the city ends up demolishing them as is happening all over the world, ie. project housing. However the better argument is that the low-rise version produces much more affordable housing, which is more eco-friendly (energy efficiency compared to all the glass etc of hi-rise) and much, much better urbanity.

        Thanks Herbert.
        Alon has already given a response:
        https://pedestrianobservations.com/2019/09/08/the-future-is-not-retro/
        and:
        https://pedestrianobservations.com/2021/01/27/kwcimby/

        • Eric2

          Some people view skyscrapers as dystopian, but plenty of other people view Faluház as dystopian. The bottom line is that extremely high population densities inevitably entail some compromises in terms of open space, available sunlight, disruptions from neighbors, and so on. (They also have great advantages both environmentally and in terms of access to city amenities.) As I understand it, the compromises are roughly proportional in impact to population density, whether that density is housed in Faluház or in skyscrapers. For example, skyscrapers mean that everyone has shadows sometimes, but Faluház means that lower floors have shadows nearly all the time. If there is a choice between Faluház and skyscrapers, I would just be happy that high density is being built, and let developers and future residents choose which of the two they prefer.

          If one wants REALLY high density, geometrically the only way of achieving it is skyscrapers with lot coverage similar to Faluház. This is appropriate for business/entertainment districts, where people mostly work rather than relax – and when they relax it’s through food and human company, not through nature and quiet. I don’t think it is possible at such densities to make a residential area that many people will find pleasant. Luckily there is no need to – Faluház or isolated condo towers can provide sufficient residential density. But office districts can be REALLY dense (like Midtown Manhattan already is).

          • Herbert

            The longest residential building in Europe is this:

            And to my knowledge it – like most Vienna public housing – is pretty popular with residents…

          • Sassy

            Considering the size of the courtyard, does that even achieve a floor area ratio above 1? The District of Döbling in which it stands has overall a population of 2,900/km^2, which is comparable to the denser examples of American suburbia like Santa Clara, California. It’s not really a good example of dense urbanism.

            And at least Karl-Marx-Hof pretends to be a Euroblock, instead of the more monotonic facade of Faluház. But if you want a good example of dense low rise urbanism, then the real Euroblocks of Paris or Barcelona are much, much denser, and imho look nicer as well.

        • Sassy

          I think the video’s main point falls apart because not only are skyscrapers with floor area ratios above 10 are not hard to find, and some of those literally appear in the video. The Tokyo Metropolitan Government Building Tower 1 is about FAR 11, parts of the Shiodome renewal project are FAR 12, and Tokyo Station Yaesu side got a special exception for about FAR 16. Some skyscrapers have fairly low floor area ratios, but that isn’t really an argument against skyscrapers overall.

          He failed to address the existence skyscrapers with FAR 10+ (or even FAR 7-8+ since 100% lot coverage sucks), while constantly reminding anyone informed/paying attention that those skyscrapers exist, and get built in a city that has liberal land use policies that encourage efficient use of land, has stayed out of the tallest skyscraper race entirely, and has major geographical challenges against very tall buildings. The video refutes its own main point, because it shows that skyscrapers can achieve things impractical and even physically impossible with 10 story buildings, and are economically sensible to build in many cases.

          I’d generally agree with your comments on the secondary points.

          • Herbert

            Are there any high rise districts of appreciable size that achieve more density than the way cities were built in the Belle Epoque?

          • Sassy

            Midtown Manhattan, Central Hong Kong, Nihombashi all have much higher job density. Depending on how you define appreciable size, the immediate vicinity of major train stations in Tokyo has twice the floor area ratio of anything pre-20th-century.

            If your focus is purely residential/nighttime population density, then Mong Kok at 130k/km^2 is significantly denser than anywhere in Paris even back at their Belle Epoque peak, and is several times that of today.

          • SB

            Mid-rise all across the city vs peaky high-rise depends on whether you can upzone an entire city or just parts of it.
            Haussmann’s Paris got an opportunity to upzone its entire city under rare circumstance. I’m not sure other cities have the same opportunity.

          • Sassy

            Even if you upzone the entire city, peaky high rise makes sense because not every single location in the city is of equal convenience/access. When the 31m height limit in Japan was replaced by FAR/geometry rules, that effectively upzoned vast swaths of cities, but people actually took advantage of that upzoning in a very peaky manner.

            I think the tendency towards peakiness when not artificially constrained might be most apparent in Sapporo, which has extremely wide streets and roads, and massive blocks, compared to most Japanese cities, as a result of American consultants. This means a lot of the geometric constraints, difficulty acquiring a large lot, etc., issues when trying to build a tall building in many parts of Tokyo don’t apply. However, Sapporo is still peaky, because high density clusters around convenient locations and naturally goes down as you get further away from them.

            By having high density in the places that matter, rather than mid density everywhere, Sapporo manages to achieve well under 50% private car modal share, despite a pretty limited transit network, and medium low population density.

            Even at higher density, and bigger cities, peaky ultra high density outperforms continuous high density at minimizing car use, especially when it comes to trying to get the surrounding suburbs to be more transit oriented.

          • michaelrjames

            ” then Mong Kok at 130k/km^2 is significantly denser than anywhere in Paris”

            Maybe or not. I know many find it is easy enough to believe …. however, that Wiki entry is completely unreferenced (and the editor should do something about it). The fact that it is 4x to 5x that of Paris or 3x of the densest districts of Paris or Manhattan, tells me it is unlikely to be true. As I have pointed out many times, all sorts of nonsense gets written about cities like HK (and Tokyo etc). That sort of density is humungous and makes it suspect and might be confounding with visitors/workers who flock there during the day and part of the night too (the sentence that follows the density claim, talks of “busiest district” which is not residential density; Guinness WR reference). For example compare it to the recent development of Union Square in West Kowloon which has about 18,000 residents on 14 Ha for ≈125,000/km2. It has the Ritz-Carlton tower with 118 floors and all buildings on the site are no less than 64 floors, ie. at least 4x-6x the average in Mong Kok. While there is a lot of super-crowded, illegal, squalid housing in Mong Kok, the difference is too high to be credible (IMO).

            The only solid fact I find is: “With a population of 2,019,533 and a population density of 43,033/km2 in 2006, it [Kowloon] is the most populous urban area in Hong Kong. The [Kowloon] peninsula’s area is about 47 km2 …”

            So perhaps there are a few spots of extreme spikiness in Mong Kok, but the Kowloon area’s average once again shows that about 40k/km2 is some kind of natural threshold (Paris-15, NYC-UWS, NYC-UES are all about 41k to 42k/km2; nothing of comparable area in Tokyo is even half this density) above which people seek outside the district to live. I think we’ve noted it before but Kowloon is close to Alon’s 30-floor Euroblock fantasy in the KWCIMBY article but Mong Kok’s average height would have been less due to the airport height limit (planes coming in to land at Kai Tak flew low over Mong Kok). The cited but unreferenced density of 130k/km2 is suspiciously close to that of the Kowloon Walled City itself, so again IMO that makes the suggestion that all of Mong Kok is like that, not at all credible.

          • Sassy

            I look at the Mong Kok number as only ~1.5x the central arrondissements of Paris in the late 19th century, with mostly similar height or taller buildings, what at least looks like greater lot coverage, which seems reasonable.

            > 130k/km2 is suspiciously close to that of the Kowloon Walled City itself

            I think the popular figure for KWC is 10x that, over a million people per square kilometer.

            > 40k/km2 is some kind of natural threshold above which people seek outside the district to live.

            I agree that seems the case for areas spanning several square kilometers in first world countries, it can be greatly exceeded in smaller areas. Clearly at the block level it can be exceeded a lot, and it doesn’t seem like the square kilometer ish of Mong Kok is too unreasonable either.

            Arakawa is one of the denser wards in Tokyo at ~20k/km^2, but it’s arranged as mostly single family houses and 2-3 story apartments with some much denser buildings near train stations. The high rise mixed use towers surrounding the Nippori Station plaza is about 60k apartment units per square kilometer. Some people clearly want to squeeze in tighter than 40k/km^2, even if most people would prefer to avoid even 40k/km^2.

            The level of convenience for people to choose to live in such densities means that it won’t sustain itself over wide areas unless forced to, e.g., Mong Kok if you want to believe the Wikipedia/Guinness World Records number, and even that is only 1km^2.

          • Alon Levy

            The Upper East Side’s eastern half is around 70,000/km^2, with way more residential space per capita than Paris (let alone Hong Kong), and people want to live there. There is no upper limit but constructability.

          • michaelrjames

            @Sassy @Alon

            I think you prove my point(s). Only by cherry-picking, plus using unverified numbers, does one arrive at such extremely high numbers, that are unrealistically above actual verifiable numbers even for ‘crowded’ places like overall Kowloon. I never accepted those unverified figures of 1m+/km2 for KWC.

            Alon: “here is no upper limit but constructability”

            No one is arguing anything different. That is yet another invalid and distracting “argument” about density. Look at Burj Khalifa or NYC’s supertalls. However, even the effective density of those won’t be as high as some might imagine. Because the occupancy at any given time may be only 25% of its nominal capacity. As many architectural and engineering commentators have said, supertalls aren’t actually designed to cope with full occupancy, eg. they would fail fire regulations and elevators couldn’t cope.

            And your starting position is that these unverified densities for some unspecified subsection of Kowloon are really as high as something printed in some newspaper–these densities are NOT in the Guinness WR, and are totally unreferenced in Wiki; therefore at the very least are not valid to keep citing in an urban blog! When you proposed a consistent 30-floor height for an entire zone as you did in the KWCIMBY article there was hardly a single reader who agreed with it or thought it would ever happen. It’s your Plan Voisin! I know, I know. The KWCIMBY movement is not proposing KWC densities, but the problem is (as evidenced here) it turns into that kind of discussion!

            And I’m not even suggesting it is the “crowding” per se that causes these densities (≈40k/km2) to be a threshold. It may well be indirect things that the video author talked of; provision & quality of services, and perhaps the cost-benefit ratio of renting in such places, and displacement of less-rich by the very-rich leading to lower densities. Also, with the removal of the building height limits due to the airport and the rebuilding of lots of Kowloon, one suspects the density might actually reduce in those hi-density spikes (whatever they are). Because much of the illegal decrepitude & crowding will be designed out. OTOH clearly Union Square is an exceptional development (at 125k/m2) because of its location (on the harbour looking across to Central and on the Metro, Airport-Express and now HSR nearby). Just as demolition of KWC would have done to its local zone, ie. lowered the average density. Quite a lot of the newly recovered land of the old airport is not being built upon but is being dedicated to open space etc.

            Final point: we should not confuse office, commercial use with residential.
            ………………………………………
            OK, I put my money where my mouth (instincts) was. I downloaded the latest official census data from Hong Kong.
            https://www.censtatd.gov.hk/en/EIndexbySubject.html?scode=150&pcode=D5320189
            Here is the data, from Table E489, for Kowloon and its 5 component district councils. Mong Kok is in the Yau Tsim Mong district; for 2020:

            Region/District…….Area……..Popn…….Density
            ……………………..(km2)…….(,000)…….(per km2)
            Kowloon…………..46.95…….2,303………49,060
            Yau Tsim Mong……6.99………326.6…….46,710
            Sham Shui Po ……..9.36………440.5……47,070
            Kowloon City………10.02………425.4…….42,470
            Wong Tai Sin………9.30………418.2…….44,950
            Kwun Tong………..11.28………692.4…….61,410

            I reckon that proves my case, though I am sure some will continue to cherrypick subdistricts and repeat that unverified figure for Mong Kok. That Wiki doesn’t even give the land area for Mong Kok so I will attempt to estimate that later; from the above data I doubt it is even possible for a substantial subdistrict (of ≈1km2) to have that reported density. I might also update the Wiki with this data and challenge anyone to provide a proper reference if they want to revert it to the fictitious figure!
            Incidentally, Kwun Tong at 61k/km2 is the densest district in all of HK. (Though some valid urban districts like Tung Chung newtown have ≈100k/km2, but these districts don’t distinguish urban/developed land; in Kowloon’s case the area given here is the urban/developed land but not so for many of the outlying districts.)

          • Frederick

            > Mong Kok at 130k/km^2 is significantly denser than anywhere in Paris.

            According to page 4 of this diagram (https://www.censtatd.gov.hk/en/data/stat_report/product/B1120093/att/B11200931991XXXXB0100.pdf) from Census Bureau (and some fiddling at Google Maps), the land area of Mong Kok district was about 1.6 sq km in 1991. According to the 1991 Census (https://www.censtatd.gov.hk/en/data/stat_report/product/B1120066/att/B11200661991XXXXB0100.pdf), the population of Mong Kok district was 165k. That means the population density in Mong Kok in 1991 was over 100k per square kilometer.

            On the other hand, in 1991 the number of high-rises in Mong Kok was about zero, as michaelrjames pointed out.

            >The Upper East Side’s eastern half is around 70,000/km^2, with way more residential space per capita than Paris (let alone Hong Kong), and people want to live there. There is no upper limit but constructability.

            But how affordable is the housing?

          • Eric2

            “The Upper East Side’s eastern half is around 70,000/km^2 … and people want to live there. ”

            That’s a little misleading, the UES would be a much less attractive place to live without Central Park as a recreation space. Count 2/3 of Central Park as part of the UES, and the density numbers go down significantly.

            (In the long run if Manhattan is substantially upzoned, it will be a good idea to reclaim land from the East and Hudson rivers to serve as extra park space.)

          • Alon Levy

            This is the part farther away from Central Park, where people are not especially likely to use the park for recreation.

          • Sassy

            > Only by cherry-picking, plus using unverified numbers, does one arrive at such extremely high numbers, that are unrealistically above actual verifiable numbers even for ‘crowded’ places like overall Kowloon.

            Easily found data don’t really offer up block by block density, which is relevant when talking about density. Using apartment units over some set of blocks divided by the area on the ground they take up is probably the best approximate of residential density, and there’s no good way to calculate block level commercial density at all. Maybe just using FAR is better. Density is subject to people’s tolerance for crowding, and subjective preferences for using the space they have, so just using FAR is more objective across different people (otherwise the obvious solution for density is to just turn all cities into Dharavi).

            In any case all the “verifiable” numbers you want tend to be areas of several square kilometers, except for administrative districts that happen to be tiny such as 2nd arrondissement of Paris, and even that is massive when talking about density spikes. Considering the nature of a location can vary massively over just a few blocks, the metrics also should be at that granularity. It takes 20ish minutes to walk from Opéra to Réaumur-Sébastopol. It takes less than half of that to go from 60k housing units/km^2 right in front of Nippori Station to 15-20k housing units/km^2 in less convenient locations.

            > No one is arguing anything different. That is yet another invalid and distracting “argument” about density. Look at Burj Khalifa or NYC’s supertalls. However, even the effective density of those won’t be as high as some might imagine. Because the occupancy at any given time may be only 25% of its nominal capacity. As many architectural and engineering commentators have said, supertalls aren’t actually designed to cope with full occupancy, eg. they would fail fire regulations and elevators couldn’t cope.

            Burj Khalifa is a distracting argument about density, as there are clearly much higher FAR high rises with more capacity usage around. For example, consider the 36 story UR public housing tower on the plaza in front of Nippori Station. While it does fall short of being a skyscraper by 10m, it has 42,528m^2 of floor space over an approximately 65m x 65m block, for a FAR of over 10, and has 285 apartments (67k units/km^2), all of which occupied (can verify availability by looking at a website that helps people get in to public housing).

            It’s easy to cherry pick examples of low FAR skyscrapers, but that doesn’t disprove the existence of high FAR skyscrapers.

            > we should not confuse office, commercial use with residential.

            As I mentioned somewhere else, people do more in a city than just sleep. If the plan is to never leave home, then why live in a city in the first place. The more I think about it, the more it seems to make sense to actually fully combine the types of density, and use floor area (+ public open space area) as the primary/headline density metric. How people choose to distribute their lives over the space available is up to them.

            > cherrypick subdistricts

            Block by block (or even smaller, when blocks are massive like in Manhattan) is probably the most appropriate way to measure density, though that is hard so you have to settle for the data you can get.

            Districts, even small ones, are very coarse. Even a 1km^2 subdistrict is on the coarse side. If it was square, walking from one corner to the other is 1.4km, or a whole 20 minutes at a decent walking speed! In a world where even unambitious Americans advocate for 15 minute cities!

          • michaelrjames

            @Frederick

            I am not sure what to think of using 1991 data, especially since it was reorganised in 1994. But If Mong Kok is 1.6km2 with 165k residents (1991) its density was 103k/km2, then the rest of Yau Tsim Mong (5.39km2) has only 161k residents (using 2020 data!) which would be a density of 25k/km2. I suppose it is possible, and there are some largish parks & sporting grounds in the district that might reduce the density of its neighbouring districts. But, nah, I’m not convinced. And it was merged into the bigger administrative district for reasons, which I get to below …

            @Sassy

            I see why we are talking at cross-purposes here. My perspective is predominantly urbanist, while I am not sure what yours is; ie. why you want to consider densities at such fine level, block by block. So I am mostly interested in the unit that comprises a “livable unit” which generally corresponds to an administrative unit. It’s kind of the minimal functional element that gives the urbanist flavour. A single block or even multiple blocks can’t do that; and why KWC is so misleading in that it didn’t include any streets (which, just there, would have halved its purported density). That’s why I am not a fan of Alon’s cherrypicking of some unspecified “eastern part” of UES.

            In Paris the 20 arrondissements are fine with each having a city hall, usually at least one covered (permanent) marché, schools, ecole maternelle, etc etc. (The exception is the 1st arrondissement which is both the smallest and at least half of its area is non-residential including the Louvre + Tulieries (about 40% of total just there), Forum, Palais Royal and ≈90% of its part of the Ile de la Cité, and I don’t think there is a single school or covered marché.) In fact each arrondissement has 4 quartiers but I don’t think they serve much modern function. It might make sense to use some natural geographic divisors, like say the islands of the 1st and 4th; for example I have calculated the density of Ile St Louis (part of the 4th and where I once lived) to be approx. 50,000/km2. It reaches such densities (at no more than 6 floors) because there are no parks (only tiny ones), almost zero non-residential buildings (just the single church; no schools or covered marché; no government functions) and only narrow streets except for the two cross-river boulevards.

            By these comparisons I mean to highlight that even some subdivisions don’t quite reveal the quality I am interested in. So the Ile St Louis (and in fact the stranded bits of the 1st which at the block level would equal the Parisian average) has one of the highest densities but it is not the most lively or best-served; well it is only 0.1km2 and of course is a short walk to lively areas, but some will much prefer living in, say, the Marais just across the Pont Marie. But both are in the 4th which also includes the Saint Paul area, Arsenal (a marina in the heart of Paris), Jewish quarter of rue des Rosiers, the Pompidou, the Hotel de Ville, the BHV grand magasin not to mention Notre Dame and a dozen other historic icons. (Jim knew it was the place (to die for, ha-ha) 41 years ago; or at least Pamela Curson did.)

            But it is the bigger unit that largely determines the quality of the urbanism. If you have a single high-density block, say stranded in a park or suburban sprawl, then you won’t have all those other things like schools, ecole maternelle, or a boulangeries, cafes, bars, bistros, or metro station etc that make for a lively and walkable district. It’s why the 1st is the least interesting arrondissement from the p.o.v. of living in (with caveat that it is easily walkable to its neighbours).

            Re my remark about confusing office and residential, I was really referring to hi-rise CBD districts. My ideal is most of Paris in which almost 100% of the ground floor is given over to retail (shops & food) or ‘profession liberales’ (doctors, dentists, lawyers, realtors etc). Paris has its old CBD (centering at junction of 1, 2, 8, 9) heavily mixed in with residential and the usual (boulangeries etc) but most modern cities have a hi-rise CBD–including Paris La Defense–that are relative dead zones. Although there have been some attempts to liven them up in the last 3 decades, London’s City and Manhattan’s Wall Street were astounding dead zones after about 6pm. The new adjunct CBDs like La Defense and Canary Wharf are still pretty dead. So I don’t think we are different on this aspect.

          • michaelrjames

            Oops, I have no idea of why I wrote “Jim knew it was the place (to die for, ha-ha) 41 years ago”. Of course it was 50 years ago (on 3 July 1971) that Jim Morrison died, reputedly drowned in his bath from a heart attack, at his apartment at 17–19, Rue Beautreillis, in the Saint Paul district (though today often referred to as part of the trendy Marais district just deux pas north). He shared the apartment with Pamela Courson whose name I managed to misspell. She knew Paris well so is probably the one who chose to live there. But I do note approvingly, from Wiki: “In letters to friends, he described going for long walks through the city, alone.[65] During this time, he shaved his beard and lost some of the weight he had gained in the previous months.[66]” You see, even American slobs can civilise themselves in Paris:-)

          • Eric2

            “This is the part farther away from Central Park, where people are not especially likely to use the park for recreation.”

            Yes they are, because they mostly don’t have any closer alternatives for recreation. Central Park is only a 5-10 minute walk away from them after all.

          • Herbert

            Kowloon wasn’t high rise but mid rise, which proves my point…

          • Sassy

            > why you want to consider densities at such fine level, block by block.

            What retail/office/public space people have access to from their home in X minutes is a block by block consideration in a transit/pedestrian oriented city.

            How many people have access to a certain retail/office/public space in X minutes is a block by block consideration in a transit/pedestrian oriented city.

            It obviously makes sense then to consider density and access to urban amenities on a block by block level. A location basically on top of a major train station is closer to everything else in the city in a way that a location a 10 minute walk away isn’t. Someone who is 10 minutes away from a train station is more likely to drive than someone who lives on top of one. Someone who needs to get to a workplace 10 minutes away from a train station is more likely to drive than someone who works on top of one. Someone who drives to work is more likely to drive to a grocery store rather than picking up groceries near the train station on the way home. Block by block density is important to consider wrt urbanism.

            > So I am mostly interested in the unit that comprises a “livable unit” which generally corresponds to an administrative unit. It’s kind of the minimal functional element that gives the urbanist flavour.

            It doesn’t. By your definition, a livable unit in Tokyo is much smaller than a ward, occasionally lines up with sub-ward units like 町丁 (often translated to district but that is kinda unsatisfying) or 丁目 (often left untranslated as chome/chōme) but not necessarily.

            > In Paris the 20 arrondissements are fine with each having a city hall, usually at least one covered (permanent) marché, schools, ecole maternelle, etc etc. (The exception is the 1st arrondissement which is both the smallest and at least half of its area is non-residential including the Louvre + Tulieries (about 40% of total just there), Forum, Palais Royal and ≈90% of its part of the Ile de la Cité, and I don’t think there is a single school or covered marché.) In fact each arrondissement has 4 quartiers but I don’t think they serve much modern function. It might make sense to use some natural geographic divisors, like say the islands of the 1st and 4th; for example I have calculated the density of Ile St Louis (part of the 4th and where I once lived) to be approx. 50,000/km2. It reaches such densities (at no more than 6 floors) because there are no parks (only tiny ones), almost zero non-residential buildings (just the single church; no schools or covered marché; no government functions) and only narrow streets except for the two cross-river boulevards.

            Walking distance of each train station in Tokyo typically contains retail, schools, parks, etc.. Bigger train stations tend to have more amenities and bigger walk sheds, and the walk sheds of stations overlap, but the ~10 minute walk shed of a typical train station, ignoring any overlap, has all the daily life places. The livable unit in Tokyo is a train station and it’s walk shed.

            The biggest possible way to think of a livable unit in Tokyo is probably a notable train station and it’s walk shed. People tend to describe where they live in relation to the nearest notable train station. In casual conversation, when an adminsitrative unit and train station name overlap, people probably mean the area around the train station, e.g., “let’s go on a date in Shibuya” means the area around Shibuya Station and excludes many places in Shibuya Ward like Ebisu but includes places not in Shibuya District such as Sakuragaokacho.

            Within the livable unit there is usually visible center (near the station) and outskirts (far from the station) areas, and it’s useful to understand that the density across those two areas is very different. Businesses strongly prefer being in the “downtown” of the livable unit, and people prefer living at least close to it, or even in it if it’s not too busy.

            > But it is the bigger unit that largely determines the quality of the urbanism. If you have a single high-density block, say stranded in a park or suburban sprawl, then you won’t have all those other things like schools, ecole maternelle, or a boulangeries, cafes, bars, bistros, or metro station etc that make for a lively and walkable district.

            Within the livable unit, the distribution of density plays a big role in the quality of urbanism. Even within a 10 minute walk of the livable unit’s downtown, there is a difference in access to that downtown, and people have choices along a gradient of tradeoff between more space/quiet and more access/lively. Since the value of floor space varies a lot across a livable unit, it’s most useful to consider the density added by a high rise, block by block.

            > If you have a single high-density block, say stranded in a park or suburban sprawl, then you won’t have all those other things like schools, ecole maternelle, or a boulangeries, cafes, bars, bistros, or metro station etc that make for a lively and walkable district.

            i.e., you agree that where density is placed in a livable unit matters. In good urbanism, the high density block is placed in the downtown of a livable unit, or at least becomes the downtown of a livable unit. In places like Hong Kong, the high density block can often be a self contained livable unit in and of itself and comes with a built in train station.

          • michaelrjames

            @Sassy

            Well, you’ve gone from ‘block by block’, to ’10 minutes walk’. That is at least 1km so is a circle enclosing 3.14km2 which is something I can agree is a fair area to define a ‘livable city unit’ or a walkable neighbourhood. It approximates the size of Paris-11 (3.4km2) which has very approximately 200 blocks, while arrondissements 1 thru 4 are all smaller. People tend to write of Paris in terms of each arrondissement, though sometimes of quartiers. I know of one foodie guide solely dedicated to the (newly hipster) 11th: Paris for Food Lovers By Elin Unnes. The author is a Swede who spends part of her year in the 11th and boasts about rarely stepping outside it, like “hardly ever crosses the river”! Hispterdom gone nuts but does confirm my notions of the livable unit even if territoriality taken to silly extremes.

            I’m not sure we’re in disagreement on this.

          • Sassy

            > Well, you’ve gone from ‘block by block’, to ’10 minutes walk’.

            If I wasn’t clear, a livable unit is about a 10 minute walk, but density still has to be understood block by block, as parts of the livable unit could be 10 minutes (or even 20) away from each other. Also taking into account a realistic street network, 1km as the crow flies is on the far side for 10 minutes walking, but 1km is a pretty number so I don’t mind the approximation.

            Imagine a perfectly circular livable unit, containing a train station, shopping, school, etc., surrounded by the void. For convenience, the train station, shopping, etc., are in the center.

            If the entire livable unit was 6 story buildings with 50% coverage (including streets/parks/etc. in the uncovered 50%), then you’d have a floor area of 9.42km^2, and the mean distance anyone’s home was from the train station is about 700m or an 8-9 minute walk if you were able to do it as the crow flies.

            If everywhere within ~450m of the center were FAR 10 towers (e.g., 40 story skyscrapers with 25% coverage, or 20 story high rise but not technically skyscrapers with 50% coverage), and the rest of it were 2 story buildings with 50% coverage, you’d still have about 9.42km^2 of floor area, but the mean distance anyone’s home was from the train station is ~350m. The density of the livable unit is unchanged, and the furthest away homes are still 1000m, but now on average people are 50% closer to the train station, and people have two options for what type of environment they want to live in, either a tower or a single family detached house.

            You can add more rings of housing types for even more lifestyle options (somewhere in there could be a 7 story building if you so desire), but basically any deviation away from consistent, such that density decreases as you get further away from the center, for any given desired overall density, will result on the average distance to the center decreasing.

            This is obviously an ultra simplistic unrealistic model, but it illustrates that peaky density puts people closer to urban amenities than consistent density, for the same overall density of the livable unit. This is what makes Tokyo a more convenient city for pedestrians than Paris, despite being less dense at the ward vs arrondissement level. There is density where it counts. The second order effect is that people drive a lot less in Tokyo since the pedestrian experience is typically so convenient, which makes it more pleasant for pedestrians as well.

            People often find repetitive architecture pleasing/romantic, such as in Paris, and that generally doesn’t exist when the city is built like Tokyo. However, I think less people driving is rather pleasing/romantic as well. More importantly, Tokyo is able to push it’s transit oriented lifestyles far beyond just central Tokyo and even far beyond just the 23 Wards, means the suburbs get to enjoy the pleasing/romantic feeling of less people driving. I guess some of the banlieues have the pleasing/romantic feel of real Paris, but most of the banlieues are lacking in pleasing/romantic quality.

            > It approximates the size of Paris-11 (3.4km2) which has very approximately 200 blocks, while arrondissements 1 thru 4 are all smaller.

            Ah, but Kowloon is over an order of magnitude bigger, and the smallest ward of Tokyo is 3x bigger. Even in Paris, where the arrondissements are very small for administrative units, most administrative units are smaller than the 1km circle approximation of livable units.

            > I’m not sure we’re in disagreement on this.

            I think the thing we’re in disagreement on is whether it’s useful to understand density block by block. I guess that mirrors the disagreement on whether being able to add a ton of density on a handful of particular blocks, is useful.

          • michaelrjames

            @Sassy

            Ah, but Kowloon is over an order of magnitude bigger, and the smallest ward of Tokyo is 3x bigger. Even in Paris, where the arrondissements are very small for administrative units, most administrative units are smaller than the 1km circle approximation of livable units.

            That’s why Kowloon is divided into 5 administrative units (district councils) and they actually are quite comparable to a lot of Paris; only the ancient inner ring of arrondissements are tiny, the 9 outer arrondissements (#12 to 20) represent 67% of the land area of Paris (89km2, excluding the two big bois) and are an average of 6.7km2 in the range 5.6 to 8.5. Similar to those in Kowloon (the one with Mong Kok is 6.99km2). Note also that these newer arrondissements are more deliberate creations as administrative units unlike the inner ones which were historical; in fact a few years ago Paris mayor Anne Hidalgo threw into the ring the zany idea of changing the historic 20 arrondissements boundaries precisely because they are too mismatched (ain’t gonna happen but you get the point; econocratically she is correct). I don’t understand your last bit, as the arrondissement is the administrative unit of Paris. Each has a marie (city hall) that deals with the local matters while of course above them for integrative functions the City of Paris ties it all together. The greater Paris agglomeration of 12.4 million people has about 120 communes (more or less the equivalent of an arrondissement) each with a marie. This is the origin of the meme that France is overgoverned; it’s kinda true but OTOH, it works. Naturally in such a giant city there are overarching entities to run higher-level functions (transit etc).

            BTW, I was talking of a circle with r=1km. Any able-bodied person can cover 1km in 10 minutes easily–it’s an ordinary walking pace, not even brisk. Six km per hour. I mention it because we must resist officialdom and managerialists who seem to want to limit these kinds of things, just encouraging our laziness and mindset about what we can do, normalising pathetically low standards into city and regulatory metrics. Americans may draw the line at 450m (or 50m!) but most of us do not want to turn into the average American. Of course most American urban environments are awful to walk thru. They are boring and sap the spirit (see Gehl Door Average, below). No accident that Paris was where the flaneur and the philosophy was created. It happens to be the best walking city in the world.

            That brings me back to the thing that interests me. Urbanism. The reasons why Paris (and some other old Euro-city cores but which are generally on much smaller scale) is so attractive to most people. Yes, it has some things of generally considered beauty like some iconic architecture and grand avenues etc but actually that is not it (that’s a cherry on top). It’s the human scale that the 6-7 floors of the vast majority of its buildings retain, amidst a dense environment. In isolation single buildings don’t have that, like say Faluház or Karl-Marx Hof. No accident that those are modern versions of Haussmannian-type construction, ie. imposing the ridiculous (‘modern’) notion of a large parkland setting! Such empty space, no matter how ‘green’ is inevitably deadening, and actually perhaps counterintuitively it makes those buildings more, not less, overwhelming. It’s designed-in anti-urbanism. Small parks, squares, plazas, especially in the context of narrow streets, have the opposite effect. The Paris urban fabric has an endlessly interesting streetscape autocatalytically generated when so many people live, work and play in a dense environment. There’s a new name for this kind of thing, something like the Gehl Door Average, ie. how long can you walk along a street and maintain interest. The suburbs, and most hi-rise city, is not walkable, not just because it takes forever to get anywhere but because our reptile brains don’t like it plus we get bored out of our minds quickly.

            It also happens that Paris building height limits, largely devised in the 17th century, hit the Goldilocks point where plenty enough light reaches the street (to support avenues of trees) and walkways and apartements so that even a very dense built environment is not oppressive. If you see it in plan you might imagine it should be. But it definitely is not! There might even be another deeper programmed effect (hah, genetic of course, I am a geneticist and you must know simply everything has a significant genetic component): as a species we are thigmotactic, ie. wall-hugging. It derives from predator avoidance behaviour such as sticking close to trees (thus tree hugging induces ‘weird’ comfort) and cave-dwelling which leads ultimately to house-dwelling in human-scale rooms not ballrooms. Part of the reason why Marie-Antoinette built that hamlet (hameau de la Reine) and preferred it to the main Versailles palace. I can only conclude that the Haussmannian height fits into this predisposition whereas not much higher and it turns into something oppressive and menacing like a fortress’s massive defensive walls, or a skyscraper’s looming, inhuman bulk. It’s our deep reptilian brain, not our more modern conscious brain (frontal cortex). Faluház actually strikes me as a gigantic and aggressive defensive wall, as well as relentlessly uninteresting if you had to walk its 315m facade. Kafkaesque. Deliberately designed that way. A bit the way modern hi-rise is. Using our frontal cortex to do the ‘clever, efficient’ design then getting clobbered by our ancient limbic and lower brains after it gets built.

            > I’m not sure we’re in disagreement on this.
            I think the thing we’re in disagreement on is whether it’s useful to understand density block by block.

            and

            that peaky density puts people closer to urban amenities than consistent density, for the same overall density of the livable unit. This is what makes Tokyo a more convenient city for pedestrians than Paris

            You’re right. I don’t understand it at all. That peakiness theory simply doesn’t work. NYC is not more convenient (re transit) than Paris, nor Kowloon and especially Tokyo is not. I seriously don’t know how anyone could think that. I’ll grant that Tokyo is a very walkable city, though really that means its individual districts (one doesn’t walk between districts like one does in Paris). But that has more to do with the sheer scale of Tokyo and its condensed concentration in the centre and the wonderful catalytic result.

            Anyway, you are being way too econocratic with all those calculations (a bit like Alon on his bad days:-) however if you could do the calcs for Paris you’d find the city’s greater consistent density far outperforms any of those other cities and certainly Tokyo on your metric. (Paris Metro, serving the inner city–and a bit of the petite couronne–has 1.5bn pax pa while all of NYC subway has 1.8bn; all of greater Paris, 12.4m, has 3.3bn transit pax pa.) In fact it is proven within Paris. They have tried applying most modern architectural and psychological theories–indeed they invented a lot of them; remember Corbu lived most of his adult life in Paris but luckily, while the city has many examples of small works of his, they resisted his bigger citywide theories (Plan Voisin would have flattened most of the 1-4 arrondissements including the Marais).

            Like all around the world, in the post-war period they built hi-rise social housing in the banlieus (none inside Paris) and we know how that turned out. In the 70s-80s they relaxed the building height law for the then light-industrial eastern half of the 13th arrondissement (the western & northern bits were already developed and are Haussmannian). It got about 20+ of 31-floor apartment blocks (note, they aren’t social housing). I won’t say it’s a disaster but it ain’t wonderful either, and it didn’t increase the density of the 13th; it is at the Parisian average and only a bit denser than only 2 of the 9 outer arrondissements, this despite it being the most ‘modern’ of them all. Today it is redeemed by the last two decades of better-considered development: modern but back to approx. Haussmannian scale; see the developments around the Bibliotheque Nationale–still not my choice but an improvement over the hi-rise towers stuff. Odd thing is that it doesn’t increase density at the district level, so why do it?

            Proving yet again that hi-rise ≠ hi-density.

            Then, for the access theory you propound, that doesn’t work in the 13th either. I lived, off and on, in one of those towers and in fact in the Italie complex (4 towers) directly above the Place d’Italie station where three Metro lines pass thru. It took longer to reach a Metro from the 21st floor than walking from my 5th floor studio on Ile St Louis, even though it is further than most of Paris (one has to walk across a bridge but total ≈400m, one of the best urban walks you could wish). That cluster of towers, above a podium that includes a mini-city of retail mall, supermarkets, cinema (multiple grands ecrans, one of the few beyond the Champs-Élysées) etc was almost certainly built upon that theory. Hardly any of the architectural and social theories around hi-rise have worked out. They work for agglomeration of white-collar workers but that’s about it. They aren’t necessary for hi-density city, in fact tend to the opposite. Likewise they strongly tend to worsen housing affordability. They aren’t any better for transit or access to transit. They are worse for walkable neighbourhoods (with a few exceptions in parts of HK etc). They are clearly worse for ground-level owner-run commerce (again with a few exceptions, all in Asia; and no accident that the brutalist concrete bleakest of those towers in Paris-13, Olympiades is enlivened by being the centre of Chinatown). And most of all they are far worse for urbanism, places where people prefer to live.

          • Phake Nick

            Note that, in Hong Kong, in districts of Yau Tsim Mong (which includes Mong Kok), Sham Shui Po, as well as Kwun Tong, while there are a number of new, very high, development for high net worth individuals, most people living in these area are poor people. Most buildings were constructed around the time before or after WWII, about 8 floors high without elevator, and are subdivided into multiple units for multiple families to live inside each of them, and in some cases they are even subdivided into caged beds for people to rent a bed to stay overnight, hence the high resident density.
            That does not mean those buildings were developed with such high density in mind, and that having to retrofit those buildings into containing so many people, sometimes also including constructing illegal temporary structure on buildings rooftop, or even illegally retrofitting interior of industrial building in those districts into home of some against fire safety and all the other livability standard, is not a good/healthy example, and is an indication of housing shortage in the city, caused by many political circumstances causing supply constantly being constrained in 1980s, 1990s, 2000s, and 2010s.
            There are programs to redevelop those old buildings into 50+ floors high building that can actually house at least as much or somewhat more people comfortably than those old buildings, while also meeting latest guidelines on sunlight, ventilation, etcetc, but the pace of redevelopment are quite slow, with the government lead effort quite literally doing it only one block at a time in each district on a for-profit ground, and developers also have difficulty getting sufficient property owners in those building agree to sell their building for redevelopment.

            Also, another thing to note about is that, while residential building with 50+ floors have already become norm in Hong Kong, all those buildings still have floor area ratio less than 10. Don’t ask me how.

          • michaelrjames

            @Phake Nick: “There are programs to redevelop those old buildings into 50+ floors high building that can actually house at least as much or somewhat more people comfortably than those old buildings, while also meeting latest guidelines on sunlight, ventilation, etcetc, …”

            Yes, but that misses the main point. You got it that the density is really high because of crowding in an unplanned and in fact illegal subdivision etc. So the overall density of Kowloon is 49,000/m2, a bit less than double that of Paris or Manhattan. But replacing the low rise with hi-rise is not going to fix the underlying problem in Hong Kong, which is housing affordability. And that is the reason why this replacement is quite slow: it is not designed to rehouse the poor in those crowded old buildings because none of this stuff contains anything remotely close to affordable housing. HK stopped building affordable public housing or social housing (with subsidised rents), at anything like the rates needed, decades ago. If they had done this, it would have been in the outlying districts connected by the MTR (see below). Those people living in those awful conditions in Kowloon etc would have readily gone to such housing and obviously that would have relieved the density issue in Kowloon. But the real estate speculators–and the government (because of the tax income it provides in a so-called low-tax state) and of course that those business interests hold so much sway over government–won’t allow that to happen.

            The Tung Chung newtown opposite the new airport is an upmarket development which is very nice if you can afford it. Just to its south is Yat Tung Estate intended as social housing, originally to be a mix of more affordable housing for ownership plus subsidized rentals, but it was delayed for years, including delaying the extension of the MTR the short distance (instead residents have to first catch a bus):

            https://en.wikipedia.org/wiki/Yat_Tung_Estate
            Originally, Yat Tung Estate was to comprise homes for subsidised sale, but the Hong Kong Government suspended the Home Ownership Scheme (HOS) in 2003 due to a soft property market and pressure from real estate developers. As a result, Yat Tung Estate is entirely public rental housing.[1]

            As I continue to point out on Alon’s blog–but its owner and many readers seemingly continue to deny–building hi-rise doesn’t solve such a housing affordability problem. Indeed it makes it worse, like with NYC’s supertalls, or all the frantic building of luxe hi-rise apartments in London since mayor Boris let the developers off the leash, or Sydney ditto, and why HK has the world’s worst housing affordability, and thus the shocking conditions for far too many Hong Kongers. The latest nonsense is a pretend scheme of building a million homes on islands off Lantau. Who believes such a development could possibly be “affordable”, not to mention the issue of transit in such a location (of course they could build a MTR line undersea but that would make it even more expensive). Funny enough, Paris with its low-rise ethos is the one amongst these world cities that doesn’t have an affordability crisis.

          • Phake Nick

            @michaelrjames
            1. Hong Kong stopped building social housing. Biut now it have resumed. Any new projects are now going to have 50-70% available units as social housing
            2. Problem with those redevelopment leading to gentrification and low income residents displaced by high income residents is not a problem in itself. The bigger problem here is, since those old buildings already have not-a-low FAR, and the crowded environment mean there are more people living in those per unit of living space, those redevelopments aren’t actually adding much available unit/area onto the total available housing stock in Hong Kong, and thus cannot see a similar effect you see elsewhere, aka highrise development sucking demand from neighboring area into the tower and thus lowering the rent. Remember when the new apartments over Tai Wai station went on sale a few months ago, it received more than 30,000 applications to purchase them despite those apartments are expensive. It signify the problem with supply shortage in Hong Kong, similar to what Hong Kong experienced in early 1990s.
            3. As you have pointed out, the current land shortage in Hong Kong is a result of political decision over a weakened housing market in 1997-2003, following the early ’90s boom. Why was the Hong Kong housing market booming in early ’90s? Because the Sino-British Joint Declaration limited land supply in Hong Kong, severely tripped the supply-demand balance, resulting in crazy increase in property price and everyone want to get in. Then what happened in 1997-1998? Asian Financial crisis, and handover, which have some effect on the market, but the biggest one is probably the then-HK government announcement that they’re going to build 85,000 units a year, which if materialized will trip the supply-demand balance to the other way heavily. Unfortunately they did not, and more unfortunately is that the news have already tripped the trend of HK housing market to the other side bankrupting many buyers, which the government deemed as bad and thus decided to launch those policies from 2000s to early 2010s to limit housing supply. It is these policies that shaped the current situation of HK housing market, with housing price breaking 1997 level, supply shortage, and many peoples are trying to buy their own housing. Building more or less percent of social housing isn’t the key to solve these problems when even private housing are in shortage, and when you, say, increase public housing from 60% to 70%, you are also simultaneously reducing the amount of private housing in those development from 40% to 30%, and further constraining the already limited private housing market supply, further tripping the balance of market supply and demand, and make the property-price-to-average-salary-ratio even more worse for the years to come.
            4. As you have mentioned in the Yat Tung Estate example, what the government was doing to counter the soft housing market, is to delay the supply, this is comparable to some other policies they did, like downsizing new private development, stop selling lands to developers unless inquired, cancelling/delaying some new area development plans, reducing development density, all these are to reduce the total quantity of housing available, so that people compete in the market with their money for the amount of existing housing. If you aren’t gonna build those high apartments, then you are doing exactly the same thing the 2000s government of Hong Kong was doing, and I think everyone see the result nowadays.
            5. In term of housing affordability, I am pretty sure Shenzhen, Shanghai, Beijing, Xiamen, and Sanya are now performing worse than Hong Kong

          • Sassy

            > I don’t understand your last bit, as the arrondissement is the administrative unit of Paris.

            Agh. Even in Paris, where the arrondissements are very small for administrative units, most administrative units are BIGGER than the 1km circle approximation of livable units. Is what I should have said.

            > Any able-bodied person can cover 1km in 10 minutes easily

            Yes, however, a 1km circle is as the crow flies, which is not the typical walking path, and a 1km radius circle contains points 2km away from each other. A denser core of the circle, especially around things like train stations or offices, means those 2km trips don’t show up much.

            > Americans may draw the line at 450m (or 50m!) but most of us do not want to turn into the average American.

            I think you overestimate how far people really want to walk. Take a look at the Dutch for example https://www.peopleforbikes.org/news/best-kept-secret-dutch-biking-dutch-hardly-bike

            Cars see a handful of percent usage even at 0.5km, gets to ~10% while still under 1km, and overtake walking in modal share at around 2km, and cycling at around 3km.

            There’s a reason why Parisians drive more than Tokyoites, despite higher overall density, despite an ongoing and pretty successful so far war on cars.

            > It happens to be the best walking city in the world.

            Having walked in both, though admittedly a lot more through Tokyo, I’d say Tokyo is the best walking city in the world. Despite the lower overall density, in many places the pedestrian traffic is so high, and the streets so lively, that even non-ground floor retail can thrive, even well outside the city center. And the quieter commercial areas have a cozy/friendly quality. And if you want to live a quiet suburban (but walkable) life in a (small) single family detached house, that’s available too, for not /too/ much money, in the city proper if you really want (but the actual suburbs have great urbanism too and are even cheaper).

            Paris (intra-muros) can realistically beat central Tokyo in walkability and pleasantness through sufficient war on cars. As it stands, Paris is a walking city that has been conquered by cars due to poor choices in land use, but is currently being recaptured through political fights. Tokyo is a walking city that excels on its own merits without even trying, since it’s just so convenient and easy to walk, driving doesn’t even have an appeal that needs political fighting to deal with. Tokyo even has a strong bike culture, despite a lot of bike hostile interests like businesses that ban biking to work, and a complete disregard for every single western (European or American) best practice on cycling.

            The problem is that you can’t really ban cars in suburban Paris. The majority of both Paris and Tokyo live in the suburbs, and the urbanism of Tokyo delivers good urbanism to the suburbs much more effectively.

            > It also happens that Paris building height limits, largely devised in the 17th century, hit the Goldilocks point where plenty enough light reaches the street (to support avenues of trees) and walkways and apartements so that even a very dense built environment is not oppressive.

            It is somewhat of a goldilocks point, but there’s no reason for buildings not to get taller, as long as you respect the nature of sunlight and viewing angles. And shorter buildings on narrower streets can provide a cozy feel that is really lacking from the almost constant density of Paris.

            That’s the beauty of the Tokyo geometry and sunlight restrictions. From a distance you can kinda notice when buildings are taller than optimal for the street you’re on, but at eye level waking down the street, the buildings always feel right. Narrow streets with buildings that present themselves as low rise feel cozy, medium width streets with buildings that present themselves as mid rise have your desired feel, and a wide plaza never feels too wide because of the high rises that encircle it. This is what part of what makes the Tokyo model scalable, able to promote good urbanism all the way from the densest areas practically on top of rail hubs, all the way deep in to the suburbs.

            > NYC is not more convenient (re transit) than Paris, nor Kowloon and especially Tokyo is not.

            Tokyo is way more convenient than Paris, especially deep in to the suburbs. There’s a reason why it’s so hard to get away from a car dominated street in Paris, despite the ongoing and already pretty successful war on cars, but you can wander off a major boulevard in Tokyo for only a moment and find yourself in a cozy quiet side street, or a pedestrian dominated mid rise street not dissimilar from my favorite streets in Paris, where you can stand for quite a while without seeing a single car despite cars technically being allowed.

            If it was easier to stumble upon stuff like Rue Montorgueil in Paris, I’d like Paris a lot more. I think an evening stroll there was the first time in Paris when I understood the romance of Paris. Unfortunately most of Paris is nothing like that, and just dominated by cars.

            > But that has more to do with the sheer scale of Tokyo and its condensed concentration in the centre and the wonderful catalytic result.

            Tokyo is overall less dense than Paris. It could be denser by making every single building a bit taller and every street a bit wider, building by building and street by street, which might happen as more and more of the suburbanites move in to the 23 Wards, but it doesn’t have to be denser as Tokyo urbanism works across a wide range of densities and preferences.

            > Paris you’d find the city’s greater consistent density far outperforms any of those other cities and certainly Tokyo on your metric

            More Parisians drive than Tokyoites, especially in the suburbs, despite Paris’s ongoing and pretty successful war on cars. Tokyo urbanism is scalable, which is a strong requirement for good urbanism, since no major metropolitan area is consistent density, not even Paris. If it’s not scalable, then it can only create a good downtown, not a good city. And by city I mean major metropolitan area, since a downtown core by itself is not a city.

            > They are worse for walkable neighbourhoods

            They are much better for walkable neighborhoods, because Tokyo manages to be more walkable than Paris, despite having single family detached houses in central wards, and a lower overall density, showing the advantage of peaky density. And Tokyo manages to push good urbanism deep into the suburbs, which is where it really counts as 75% of Greater Tokyo lives outside the 23 Wards and 85% of Ile-de-France outside of Paris intra-muros.

            > They are clearly worse for ground-level owner-run commerce (again with a few exceptions, all in Asia; and no accident that the brutalist concrete bleakest of those towers in Paris-13, Olympiades is enlivened by being the centre of Chinatown)

            Parts of Tokyo are such a lively place that it’s common to see even non-ground-level owner-run commerce. It is in Asia, but why should that matter at all?

            If anything developed East Asia should be more important as an example to Westerners, as it has different traditions in urbanism, many of which work much better.

          • michaelrjames

            @Sassy

            Walkability is very subjective. I’ve done Tokyo and, like I said, it is good walking, though again one had to first take the Metro to get somewhere and back. One of the great things about Paris is that you can just walk to any part of the city (the 100km2 of intramuros-Paris), North to South is less than an hour and East-West is about 75-90mins. Also, by walking and walkability I was speaking in the flaneur sense, ie. the endlessly interesting streetscape and people-scape. There are few places with the terrasse cafe culture. I like the laneway system of Tokyo but I think you exaggerate the problems of cars in Paris. It doesn’t really detract from walkability or enjoyment. It’s subjective but Paris is a palimpsest of 2,000 years of history, and the most recent very important 500 years in which it played a major role in creating today’s world. From its Roman foundation (its mini Arenes de Lutece was built at the same time as Rome’s coliseum), to the middle ages, Renaissance and the great age of kings (Louis IV Versailles etc), the Enlightenment, to the Revolutions (1789, 1830,1848, 1870) that changed the world, then the modern era (Haussmann, Belle Epoque, Art Deco, Great War, inter-war, WW2, post-war etc. (The only other city that has anything comparable–in the ensemble–is London, however it is a mess and quite tiring to walk I find.)

            It is somewhat of a goldilocks point, but there’s no reason for buildings not to get taller, as long as you respect the nature of sunlight and viewing angles. And shorter buildings on narrower streets can provide a cozy feel that is really lacking from the almost constant density of Paris.

            There are too many contradictions in that. I really don’t think it is a matter of opinion of what you lose as buildings get taller. Which is different to some people having different opinions … on some matters, some opinions are demonstrably wrong; you can’t countermand physics. NYC, at behest of its developers, has constantly changed the rules (which began from the same ones as Paris concerning light & air on the street), from setbacks, to trading air-rights and today removing all kinds of Fire & Safety regs for those super-talls; and like with the Port Authority overriding its own rules on its own buildings (WTC Twin Towers) it cannot change physics or how fire brings down naked steel-frame buildings. As you go higher those things I mentioned happen, with very few advantages except for whitecollar workplaces (some speculate covid may even change that but probably not). The only thing gained by going higher is more accommodation, but note not necessarily higher density and certainly not affordability; it seems illogical but it’s the reality. Manhattan has plenty of tall residential–and even its low-rise is higher at about 12 floors (>50% more than the Parisian average), yet it is only marginally more dense than Paris (≈28k/km2 versus ≈25k/km2). Tokyo 23-ku is ≈15k/km2. Even Kowloon at 49k/km2 shows the limits of higher building and the very high density is more a result of inhuman ultra-crowding and illegal apartment subdivision or sharing, and coffin lodgings etc. My main point is that one doesn’t need hi-rise to achieve high density (and plenty of evidence suggests the Paris-Manhattan density is as good as a city ever needs).

            On transit:
            >Tokyo is way more convenient than Paris, especially deep in to the suburbs …

            Again we’re going to have to agree to disagree. I know Tokyo Metro (subway etc) has a formidable reputation but there’s a dirty little secret: too many people spend hours in travel each day, often in quite uncomfortable conditions. When I worked at the Cancer Institute (Otsuka, Tokyo) there were people with a 2 hour commute both ways. About 4 to 6 people were sleeping in the lab during the week (3-4 nights) to avoid the commute–to be fair some may have left their families in towns/cities elsewhere in Japan to work for a year or two in this lab; so a shortish-term compromise for career reasons; I was almost sleeping in the lab too but not really … long hours but I was staying in a hotel a short walk away which would not have been viable if I lived there; having said that there was one American in the lab and he was the only one (of about 25) who lived in Central Tokyo; all the others had pretty terrible commutes, or worked shorter weeks while sleeping in the lab. This segues to the following:

            More Parisians drive than Tokyoites, especially in the suburbs, despite Paris’s ongoing and pretty successful war on cars. Tokyo urbanism is scalable, which is a strong requirement for good urbanism, since no major metropolitan area is consistent density, not even Paris.

            Fundamentally I don’t agree that Tokyo urbanism is scalable. Except in the sense that it, and Houston and Phoenix and Beijing etc do keep growing, but not without a price, and the generation of a kind of urbanism/anti-urbanism I don’t want. There are too many problems created by Japan’s rather weird laissez-faire development to go into here (just two: the intermingling of nasty industrial plants with residential, or the years and years it can take before private development finally gets sewered). One can say it “works” but the cost is at the personal level, which really is the only level that matters …
            OTOH, in some senses Ile de France shows that this French mega-city has achieved a kind of scalability. It’s the largest city in the EU (only Moscow is bigger in Europe) and even at its farthest points it is still only an hour on the RER into central Paris. The reason why Paris is a better model than Tokyo is again due to its density. It can continue to support growth without spreading further and further out, without overly stressing its existing infrastructure (transit, power etc). Even the bits out towards the edge of Ile de France are relatively dense and that is how it supports the RER network. Melun is a pleasant town of 40,000, density of 5,000/km2, on the Seine about 50km south of Paris (the edge of the Ile de France) and the terminus of RER-D2 which run frequently, taking 55mins to Chatelet. For suburbs, whether Petite Couronne (inner ring) or Grand Couronne (outer ring; the rest of Ile de France) there is a huge range of type; just for Petite Couronne (which is 10 to 30mins from Chatelet) and its 6 million residents: neo-Haussmannian (Boulogne-Billancourt, Montrouge), stockbroker belt (Puteaux, Suresnes, leafy rich SFH (Neuilly, Meudon), middle-class suburban (Nogent-sur-Marne), lower-middle (Villejuif, Ivry etc), ritzy former royal parks (Versailles, Sceaux, St Cloud), immigrant project housing (St Denis, the 93) and more. The reason it can be considered scalable is that, because it builds in quite compact form, each remains walkable and servicable by the RER, and of course most of those banlieu I named will be soon served by the orbital GPX.

            So, yes, more Parisians drive, though you really mean Franciliens (residents of Ile de France outside intramuros-Paris). Not many actual Parisians drive because like in Tokyo you’d have to be slightly nuts. There’s more provision for parking or garaging private cars (outside intramuros-Paris), and the excellent road system can cope though of course it does create pollution, and some congestion. This will change with GPX and more provision for cycling etc. I am very interested to see how Métropole du Grand Paris* (ie. plans to improve transit and urban developement in Ile de France) develops over the coming years; it’s a kind of Paris-ification. The bones are already there. I’m not sure I see the same thing in greater Tokyo.

            If anything developed East Asia should be more important as an example to Westerners, as it has different traditions in urbanism, many of which work much better.

            I agree, to a point (as in my comments on Tokyo urbanism, not everything). The reason I mentioned the Asians that live around and work in Olympiades Paris-13 is to agree that they can make unpromising dense urban situations work better than westerners. Most hi-rise zones in western cities are either dead zones or danger zones. Parts of Manhattan are a possible exception. Most such zones in US cities are dead and bleak. Ditto the residential towers around London’s Canary Wharf and spreading along the Thames; they are trying to remedy that but it is not easy when they are essentially rich ghettos which don’t naturally support diverse ground-level activities. Having said all that, I return to my premise: one doesn’t need hi-rise for good density and certainly not for good urbanism.

          • michaelrjames

            *In that last post, for the Metropole Grand Paris, I tried to link to the stuff below but the link has rotted (it may be on the jll site but OTOH it is from the Sarkozy era so possibly has been airbrushed from history …). Given that GPX is so critical to its implementation, and thus the relevance to this post on regional rail, I will claim it not to be a hijacking … Oh, and while many cities expound such grand plans, Paris actually has a pretty good track record of implementation.

            http://www.grand-paris.jll.fr/en/grand-paris-project/
            The «Grand Paris» project is the spiritual child of Nicolas Sarkozy and Christian Blanc, former Secretary of State for the development of the Capital region. In May 2004, Christian Blanc published a report entitled “Pour un écosystème de la croissance” (For an ecosystem of growth) as part of an economic development project that had been given to him by the then President. He noted the extremely centralised organisational structure in France (and in the Greater Paris Region in particular) that was impeding the country’s reactivity and ability to innovate. Amongst other things, he recommended the creation of ‘competitiveness centres’ (“clusters”). He stipulated the need for a “territorial player that would be strong and uncontested, able to act as a catalyst to activity and align disparate efforts”. These observations have, undeniably, inspired the current projects that form «Grand Paris».
            The aims of the «Grand Paris» of tomorrow in 10 key ideas :
            1. Making Paris better equipped to defend its status as a world city via the implementation of large, iconic projects.
            2. A city of knowledge for which economic development will focus on the creation or strengthening of large competitiveness centres,
            3. A more intense city,
            4. A rethinking of road transport and an improved public transport offering,
            5. The creation or strengthening of urban centres,
            6. Better integration between districts,
            7. Preservation of the green belt
            8. Enhancement of the Seine and its tributaries as connecting threads of the city,
            9. Adapted governance to allow more harmonious and coherent development,
            10. And therefore … A sustainable «Grand Paris».

          • Phake Nick

            *clarification, in my previous reply, by “any new projects”, I mean any development of an entire new district

          • Sassy

            > One of the great things about Paris is that you can just walk to any part of the city (the 100km2 of intramuros-Paris), North to South is less than an hour and East-West is about 75-90mins.

            This is an artifact of Paris intra-muros being an arbitrary, small area. Paris, the metropolitan area, cannot easily be walked across.

            > Also, by walking and walkability I was speaking in the flaneur sense, ie. the endlessly interesting streetscape and people-scape.

            The neat thing about randomly wandering between two distant points in central Tokyo, if you ever wanted to do that for any reason, is how you go through such varied streetscape. The character of streets varies a lot over quick walks, and the design of buildings varies a lot even between comparable streets, and buildings on the same street tend to all look different. Commercial areas are vibrant both in human activity, and in actual colorful signage and advertising which show the life of the commercial area even if you walk by during a quiet time.

            > It’s subjective but Paris is a palimpsest of 2,000 years of history, and the most recent very important 500 years in which it played a major role in creating today’s world.

            That’s history and architecture, not urbanism.

            > There are too many contradictions in that.

            How so?

            > some opinions are demonstrably wrong; you can’t countermand physics.

            The basic rules in Tokyo let everything work together very well, at pretty much any street width, character, and building height. Everything from cozy streets with 1-2 story buildings, to a big plaza or intersection surrounded by high rises, all just fits together.

            > My main point is that one doesn’t need hi-rise to achieve high density

            High rise achieves high density across a couple blocks, which is the most relevant area over which to measure density. Even at Tokyo density, concentrating most of the population of a country into a few megacities, can leave the vast majority of land as wilderness. The problem isn’t getting people to fit into cities in a people per area sense, but to fit in the sense that people must be willing and able to live transit and pedestrian oriented lifestyles, and being able to put a lot of floor space (particularly office and retail) basically on top of train stations, helps with that.

            High rise is part of good urbanism, as variable density is part of good urbanism, and high rise is necessary to create those density peaks in already pretty dense areas.

            > too many people spend hours in travel each day

            This is true of Paris as well. Commute times are generally a question of tolerance, and people are just willing to commute further and longer by public transit than driving. The overall lower average commute time of Île-de-France vs Greater Tokyo is mostly an artifact of more people driving.

            51% of Franciliens who commute by transit have 2 hour or longer commutes as per survey by Moovit. I don’t see a similar statistic for Greater Tokyo, but 54% of Greater Tokyo salarymen (only 85% commute via transit, but they tend to commute much further and longer than the typical worker) have a 2 hour or longer commute as per survey by AtHome.

            > Fundamentally I don’t agree that Tokyo urbanism is scalable

            It certainly has scaled better than Paris. Itto Sanken is more transit/walking friendly than Île-de-France, is home to more people, is home to a larger share of the national population, and requires less top down planning and coordination.

            > There are too many problems created by Japan’s rather weird laissez-faire development to go into here

            There are also plenty of problems created by the micromanagement, top-down control, regulatory capture, and failure to adapt that has served as the basis of typical thought in Western urban planning in the past 100-200 years or so. Paris has managed to evade some of the issues that plague NYC/London, but any non-laissez-faire land use policy is inherently fragile and inflexible.

            > The reason it can be considered scalable is that, because it builds in quite compact form, each remains walkable and servicable by the RER

            This is the theory, but in real life, it requires an active political fight to get people out of cars, suggesting that it is more car friendly and car centric.

            > Most hi-rise zones in western cities are either dead zones or danger zones.

            I think this is because high rise zones in Western cities tend to be much bigger than what the area can really support. Most high rise zones in Tokyo are only a few blocks, and it’s nearly always a quick walk between a skyscraper and a single family detached house, and between those two you’d pass through the buildings in between, built where the make the most sense. Hong Kong has pretty big high rise zones, but it’s also artificially dense due to how the government monopoly on transit and land works.

          • michaelrjames

            @Sassy

            I don’t agree with much of that, or even understand the sense (everything “artifactual” is the consequence of some action in the past), but vive la différence. That’s why every big city has its different attractions … and its advocates. Except for the relentless trend for everything to become the same hi-rise bore. At least Tokyo hasn’t done that, even as London tries …

            Re the link below: I usually don’t endorse such vulgarity but there are indeed times when one feels like that. Not as elegant as Sabrina’s “Paris is always a good idea” but very similar intent. I suspect it was uttered by many an expat headed for the Ville Lumière, probably including Josephine Baker when in 1925 she quit the USA permanently for France. And now Macron has made her a Permanent Parisian, more than that of course, an immortal on the Pantheon hill.

            Just 2 weeks ago:

        • Sassy

          American threads are built stronger and heavier, as derailment is considered expected and unavoidable. This increases costs, and people have to be fired.

  6. adirondacker12800

    would even beat the subway in normal service to Grand Central.
    Very unlikely except for the dozens of people who happen to live next to the tracks and want to get to Grand Central. If the Lexington Ave. trains aren’t running the 7th Ave. trains could still be running. Or vice versa. And there is more to life than Grand Central.

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