Category: Good Transit

More on Six-Minute Service in New York

Two years ago I wrote about how New York should aim to run every bus and subway service every six minutes off-peak. Buses would require a combination of aggressive bus redesign and speedup treatments for this to be viable. The subway already has very low variable operating costs off-peak and such a boost in frequency would naturally increase efficiency; New York City Transit gets around 550 service-hours annually per train driver, whereas the Berlin U-Bahn with its flat all-day schedule gets around 900. But now, the more mainstream New York-area transit advocacy group Riders’ Alliance has its own proposal for six-minute service, which it has aggressive marketed using the hashtag #6minuteservice.

This is a good campaign and I hope more people in the region take notice and push for it until the state implements it in full. The impact on passenger convenience is massive, not just in the form of shorter waits but also higher reliability coming from better timetabling, and hopefully also slightly more speed coming from said higher reliability. The proposal says that it would take $250 million a year in extra spending to effect this system, and it’s unknown but plausible that it would increase ridership by enough to defray this cost entirely, even without any efficiency treatments to reduce unit costs.

What’s in the Riders’ Alliance proposal?

Between 5 am and 9 pm on weekdays, and between 8 am and 10 pm on weekends, all subway routes and the top 100 bus routes in the city should run at worst every six minutes. This echoes a report by the comptroller’s office from last year, recommending this as an alternative to rush hour-focused service by bringing up corona-related ridership decreases.

It’s not stated but I think the subway routes in question are reckoned by letter or number, which means the A train runs every six minutes but each of its two branches runs every 12. This is fine – the two branches of the A are exceptionally far out, which is why a single service splits to them, where elsewhere in New York each branch gets its own number or letter.

The implications for timetabling

Timetabling a consistent all-day service is much easier than timetabling bespoke service patterns. The Riders’ Alliance proposal aims to face the general public rather than planners and therefore omits this benefit, but this benefit reaches passengers as well, in non-obvious ways.

First, if all trains and buses run every six minutes, then it’s possible to set up clockface timetables. These don’t matter very much if they run every six minutes, but they do if they run every 12, as I expect the two A branches to. The same is true of buses that branch: some outer ends may run every 12 minutes, in which case they can and should run on repeating clockface timetables that passengers can memorize. Passengers who can remember “my bus leaves at :01, :13, :25, :37, and :49” without having to consult timetables or trip planners all the time are likelier to take the trip; this was my commute for a year in Vancouver.

The A train today runs every 15 minutes on each branch but it’s not on a consistent clockface schedule, which depresses ridership. In effect, current practice is little different from what Swiss planners warn of: they say the best way to reduce ridership is to run service every 11, 13, or 17 minutes, rather than every 12 or 15 on a clockface pattern.

Second, if all trains run on the same frequency, then service planning on a complexly interlined system like New York’s becomes more tractable. Today, every train runs on a separate frequency, often different from the services it shares track with. The 2 and 3 trains share track most of the way, from Franklin Avenue to 135th Street, but the 2 is just a little more frequent, resulting in the following northbound timetable at Franklin:

10:03: 2
10:07: 3
10:12: 2
10:15: 3
10:21: 2
10:28: 3
10:32: 2
10:34: 3
10:37: 2
10:41: 3
10:43: 2
10:49: 2
10:51: 3
10:57: 3
11:01: 2
11:03: 3
11:09: 2
11:15: 3
11:17: 2
11:22: 3
11:24: 2
11:28: 3

This is irregular both on the trunk and on each individual service – the 2 on average runs every eight minutes but has a 12-minute gap, and the 3 runs on average every nine but also has a 12-minute gap. It’s an unavoidable consequence of the combination of extensive reverse-branching and subway frequency guidelines that run different services at different headways. The six-minute service proposal straightens this by aligning the trains to a single frequency, with regular alternation between successive trains on trunks.

And third, another benefit of a regular frequency to planning is that schedule planners can reliably avoid merge conflicts. This, in turn, speeds up service, which is full of planned delays and schedule padding at pain points. It’s not a full substitute for deinterlining, which would eliminate the merge conflicts at the worst junctions, but it makes it viable to no longer write impossible schedules with the planning department that New York City Transit has.

Service quality and demographics

Both Riders’ Alliance and the comptroller report it uses as its source point out demographic differences between peak and off-peak riders: rush hour subway commuters have a median income of $50,783 a year, even higher (slightly) than drivers, but off-peak subway commuters have a median income of $37,048 and bus commuters have a median income of $30,374.

In both reports this is taken to be indicative that off-peak service is mostly for poorer people, but it’s not the right analysis. The picture that emerges from the data is not that in general rush hour commuters outearn off-peak commuters; for one, most off-peak commutes are done by car, not by public transportation. Rather, what’s going on is that off-peak public transit quality is bad and this suppresses ridership among those who can afford a car.

By the same token, we can look at the incomes of commuters in regions of the United States that have no public transit to speak of – maybe some buses or even a few trains but with rounding-error ridership and low single-digit modal split. In metro New York, public transit and car commuters have about the same median income, and in some secondary transit cities like Chicago public transit commuters actually outearn drivers, since service to non-CBD destinations is so bad it suppresses ridership below median income more than above it. But in places like Los Angeles, the median income of transit commuters is not much more than half that of car commuters, because service quality is so bad that anyone who can afford to drive does.

The upshot of this is that better off-peak transit service is going to increase the average income of off-peak transit users, by attracting people who currently drive. This is also going to lead to higher-socioeconomic status shifts: higher levels of degree attainment, a larger proportion of white riders, a larger proportion of native-born riders.

I bring this up because a rise in the relative average income of users as service quality improves means the improvement is working as intended. It doesn’t mean the subway is gentrifying or turns away poorer riders, it just means it no longer repels riders who can afford to drive. This is important, because too much American transit planning is based on market segmentation in which service is supposed to be for a specific class of rider, and if the demographics are changing it means it’s being revamped for a different class. In reality, there’s just one transit system for one city and income differences are indicative of quality differences and not of inherent differences in the travel market.

How much does this cost? What is the ridership impact?

The Riders’ Alliance proposal says the additional cost of the program is $250 million a year in operating expenses. In 2019, NYCT spent $8.8 billion on operations and got $4.6 billion in fares, so this is in theory a 6% increase in subsidy, and in practice a little less as better service attracts more fare-paying riders. This is without any concurrent attempts to use the increase in service to increase efficiency (read: reduce unit staffing levels) and, I think, without bus speedups that permit much higher frequency for the same cost.

It’s unclear what the revenue impact should be; the ridership impact can be estimated from longstanding results in the literature about ridership-frequency elasticity, which in the case of NYCT should be about 0.4. The proposal increases off-peak service on the subway by around 50% in principle and a bit more in practice because of the reduced variability in frequency, say two-thirds: most lines are to go from 10- to six-minute headways and the rest, which are mostly more frequent than this, get a smaller increase that we round up to two-thirds by taking the impact of higher reliability into account. This means an increase in off-peak ridership of around 23%. The bus impact is even larger – in Brooklyn the median bus headway is right between 12 and 15 minutes, and even taking into account that the busiest buses do much better, this is close to a doubling of the effective frequency.

In turn, most ridership is off-peak. In 2019, peak (7-10 am) ridership into the Manhattan core was 923,000 per weekday, amounting to 44% of ridership entering the Manhattan core on a weekday, or around 33% of all inbound weekday ridership and 27% of all ridership. Even adding a bit to account for peak ridership that doesn’t enter Manhattan, only about a third of subway ridership in New York was at the peak before corona; the peak share has fallen since, but is slowly creeping back up as workers slowly return to the office. Raising two-thirds of ridership by 23% is massive – it’s a 15% systemwide increase for a much smaller increase in operating costs, and a somewhat larger increase in bus ridership to boot.

Unfortunately, I can’t turn this into a revenue impact estimate. While the demographics in the section above specify off-peak commuters, the studies that my ridership estimate is based on measure riders, including peak commuters who ride more often for non-work trips. Such riders already have monthly passes, so making it easier for them to ride is excellent for the city’s long-term health but doesn’t defray the added cost. Converted riders who are not already on the system as well as the odd peak rider who doesn’t already have a pass do generate more revenue, but I don’t know how many there are; these need to be a little more than a third of the overall increase in ridership to fully defray costs, which sounds plausible to me.

Eno’s Project Delivery Webinar

Eno has a new report out about mass transit project delivery, which I encourage everyone to read. It compares the American situation with 10 other countries: Canada, Mexico, Chile, Norway, Germany, Italy, South Africa, Japan, South Korea, and Australia. Project head Paul Lewis just gave a webinar about this, alongside Phil Plotch. Eno looks at high-level governance issues, trying to figure out if there’s some correlation with factors like federalism, the electoral system, and the legal system; there aren’t any. Instead of those, they try teasing out project delivery questions like the role of consultants, the contracting structure, and the concept of learning from other people.

This is an insightful report, especially on the matter of contract sizing, which they’ve learned from Chile. But it has a few other gems worth noting, regarding in-house planning capacity and, at meta level, learning from other people.

How Eno differs from us

The Transit Costs Project is a deep dive into five case studies: Boston, New York, Stockholm (and to a lesser extent other Nordic examples), Istanbul (and to a lesser extent other Turkish examples), and the cities of Italy. This does not mean we know everything there is to know about these cases; for example, I can’t speak to the issues of environmental review in the Nordic countries, since they never came up in interviews or in correspondence with people discussing the issue of the cost escalation of Nya Tunnelbanan. But it does mean knowing a lot about the particular history of particular projects.

Eno instead studies more cases in less detail. This leads to insights about places that we’ve overlooked – see below about Chile and South Korea. But it also leads to some misinterpretations of the data.

The most significant is the situation in Germany. Eno notes that Germany has very high subway construction costs but fairly low light rail costs. The explanation for the latter is that German light rail is at-grade trams, the easiest form of what counts as light rail in their database to build. American light rail construction costs are much higher partly because American costs are generally very high but also partly because US light rail tends to be more metro-like, for example the Green Line Extension in Boston.

However, in the video they were asked about why German subway costs were high and couldn’t answer. This is something that I can answer: it’s an artifact of which subway projects Germany builds. Germany tunnels so little, due to a combination of austerity (money here goes to gas subsidies, not metro investments) and urbanist preference for trams over metros, that the tunnels that are built are disproportionately the most difficult ones, where the capacity issues are the worst. The subways under discussion mostly include the U5 extension in Berlin, U4 in Hamburg, the Kombilösung in Karlsruhe, and the slow expansion of the tunneled part of the Cologne Stadtbahn. These are all city center subways, and even some of the outer extensions, like the ongoing extension of U3 in Nuremberg, are relatively close-in. The cost estimates for proposed outer extensions like U7 at both ends in Berlin or the perennially delayed U8 to Märkisches Viertel are lower, and not too different per kilometer from French levels.

This sounds like a criticism, because it mostly is. But as we’ll see below, even if they missed the ongoing changes in Nordic project delivery, what they’ve found from elsewhere points to the exact same conclusions regarding the problems of what our Sweden report calls the globalized system, and it’s interesting to see it from another perspective; it deepens our understanding of what good cost-effective practices for infrastructure are.

The issue of contract sizing in the Transit Costs Project

Part of what we call the globalized system is a preference for fewer, larger contracts over more, smaller ones. Trafikverket’s procurement strategy backs this as a way of attracting international bidders, and thus the Västlänken in Gothenburg, budgeted at 20,000 kronor in 2009 prices or around $2.8 billion in 2022 prices, comprises just six contracts. A planner in Manila, which extensively uses international contractors from all over Asia to build its metro system (which has reasonable elevated and extremely high underground costs), likewise told us that the preference for larger contracts is good, and suggested that Singapore may have high costs because it uses smaller contracts.

While our work on Sweden suggests that the globalized system is not good, the worst of it appeared to us to be about risk allocation. The aspects of the globalized system that center private-sector innovation and offload the risk to the contractor are where we see defensive design and high costs, while the state reacts by making up new regulations that raise costs and achieve little. But nothing that we saw suggested contract sizing was a problem.

And in comes Eno and brings up why smaller contracts are preferable. In Chile, where Eno appears to have done the most fieldwork, metro projects are chopped into many small contracts, and no contractor is allowed to get two adjacent segments. The economic logic for this is the opposite of Sweden’s: Santiago wishes to make its procurement open to smaller domestic firms, which are not capable of handling contracts as large as those of Västlänken.

And with this system, Santiago has lower costs than any Nordic capital. Project 63, building Metro Lines 3 and 6 at the same time, cost in 2022 PPP dollars $170 million/km; Nya Tunnelbanan is $230 million/km if costs don’t run over further, and the other Nordic subways are somewhat more expensive.

Other issues of state capacity

Eno doesn’t use the broader political term state capacity, but constantly alludes to it. The report stresses that project delivery must maintain large in-house planning capacity. Even if consultants are used, there must be in-house capacity to supervise them and make reasonable requests; clients that lack the ability to do anything themselves end up mismanaging consultants and making ridiculous demands, which point comes out repeatedly and spontaneously for our sources as well as those of Eno. While Trafikverket aims to privatize the state on the British model, it tries to retain some in-house capacity, for example picking some rail segments to maintain in-house to benchmark private contractors against; at least so far, construction costs in Stockholm are around two-fifths those of the Battersea extension in London, and one tenth those of Second Avenue Subway Phase 1.

With their broader outlook, Eno constantly stresses the need to devolve planning decisions to expert civil servants; Santiago Metro is run by a career engineer, in line with the norms in the Spanish- and Portuguese-language world that engineering is a difficult and prestigious career. American- and Canadian-style politicization of planning turns infrastructure into a black hole of money – once the purpose of a project is spending money, it’s easy to waste any budget.

Finally, Eno stresses the need to learn from others. The example it gives is from Korea, which learned the Japanese way of building subways, and has perfected it; this is something that I’ve noticed for years in my long-delayed series on how various countries build, but just at the level of a diachronic metro map it’s possible to see how Tokyo influenced Seoul. They don’t say so, but Ecuador, another low-cost Latin American country, used Madrid Metro as consultant for the Quito Metro.

The Baboon Rule

I made a four-hour video about New York commuter rail timetabling on Tuesday (I stream on Twitch most Tuesdays at 19:00 Berlin time); for this post, I’d like to extract just one piece of this, which informs how I do commuter rail proposals versus how Americans do them. For lack of a better term, on video I called one of the American planning maxims that I violate the baboon rule. The baboon rule states that an agency must assume that other agencies that it needs to interface with are run by baboons, who are both stupid and unmovable. This applies to commuter rail schedule planning but also to infrastructure construction, which topic I don’t cover in the video.

How coordination works

Coordination is a vital principle of good infrastructure planning. This means that multiple users of the same infrastructure, such as different operators running on the same rail tracks, or different utilities on city streets, need to communicate their needs and establish long-term horizontal relationships (between different users) and vertical ones (between the users and regulatory or coordinating bodies).

In rail planning this is the Verkehrsverbund, which coordinates fares primarily but also timetables. There are timed transfers between the U- and S-Bahn in Berlin even though they have two different operators and complex networks with many nodes. In Zurich, not only are bus-rail transfers in the suburbs timed on a 30-minute Takt, but also buses often connect two distinct S-Bahn lines, with timed connections at both ends, with all that this implies about how the rail timetables must be built.

But even in urban infrastructure, something like this is necessary. The same street carries electric lines, water mains, sewer mains, and subway tunnels. These utilities need to coordinate. In Milan, Metropolitana Milanese gets to coordinate all such infrastructure; more commonly, the relationships between the different utilities are horizontal. This is necessary because the only affordable way to build urban subways is with cut-and-cover stations, and those require some utility relocation, which means some communication between the subway builders and the utility providers is unavoidable.

The baboon rule

The baboon rule eschews coordination. The idea, either implicit or explicit, is that it’s not really possible to coordinate with those other agencies, because they are always unreasonable and have no interest in resolving the speaker’s problems. Commuter rail operators in the Northeastern US hate Amtrak and have a litany of complaints about its dispatching, and vice versa – and as far as I can tell those complaints are largely correct.

Likewise, subway builders in the US, and not just New York, prefer deep tunneling at high costs and avoid cut-and-cover stations just to avoid dealing with utilities. This is not because American utilities are unusually complex – New York is an old industrial city but San Jose, where I’ve heard the same justification for avoiding cut-and-cover stations, is not. The utilities are unusually secretive about where their lines are located, but that’s part of general American (or pan-Anglosphere) culture of pointless government secrecy.

I call this the baboon rule partly because I came up with it on the fly during a Twitch stream, and I’m a lot less guarded there than I am in writing. But that expression came to mind because of the sheer horror that important people at some agencies exuded when talking about coordination. Those other agencies must be completely banally evil – dispatching trains without regard for systemwide reliability, or demanding their own supervisors have veto power over plans, or (for utilities) demanding their own supervisors be present in all tunneling projects touching their turf. And this isn’t the mastermind kind of evil, but rather the stupid kind – none of the complaints I’ve heard suggests those agencies get anything out of this.

The baboon rule and coordination

The commonality to both cases – that of rail planning and that of utility relocation – is the pervasive belief that the baboons are unmovable. Commuter rail planners ask to be separated from Amtrak and vice versa, on the theory that the other side will never get better. Likewise, subway builders assume electric and water utilities will always be intransigent and there’s nothing to be done about it except carve a separate turf.

And this is where they lose me. These agencies largely answer to the same political authority. All Northeastern commuter rail agencies are wards of the federal government; in Boston, the idea that they could ever modernize commuter rail without extensive federal funding is treated as unthinkable, to the point that both petty government officials and advocates try to guess what political appointees want and trying to pitch plans based on that (they never directly ask, as far as I can tell – one does not communicate with baboons). Amtrak is of course a purely federal creature. A coordinating body is fully possible.

Instead, the attempts at coordination, like NEC Future, ask each agency what it wants. Every agency answers the same: the other agencies are baboons, get them out of our way. This way the plan has been written without any meaningful coordination, by a body that absolutely can figure out combined schedules and a coordinated rolling stock purchase programs that works for everyone’s core passenger needs (speed, capacity, reliability, etc.).

The issue of utilities is not too different. The water mains in New York are run by DEP, which is a city agency whereas the MTA is a state agency – but city politicians constantly proclaim their desire to improve city infrastructure, contribute to MTA finances and plans (and the 7 extension was entirely city-funded), and would gain political capital from taking a role in facilitating subway construction. And yet, it’s not possible to figure out where the water mains are, the agency is so secretive. Electricity and steam are run by privately-owned Con Ed, but Con Ed is tightly regulated and the state could play a more active role in coordinating where all the underground infrastructure is.

And yet, in no case do the agencies even ask for such coordination. No: they ask for turf separation. They call everyone else baboons, if not by that literal term, but make the same demands as the agencies that they fight turf wars with.

When Different Capital Investments Compete and When They Don’t

Advocates for mass transit often have to confront the issue of competing priorities for investment. These include some long-term tensions: maintenance versus expansion, bus versus rail, tram versus subway and commuter rail, high-speed rail versus upgraded legacy rail, electronics versus concrete. In some cases, they genuinely compete in the sense that building one side of the debate makes the other side weaker. But in others, they don’t, and instead they reinforce each other: once one investment is done, the one that is said to compete with it becomes stronger through network effects.

Urban rail capacity

Capacity is an example of when priorities genuinely compete. If your trains are at capacity, then different ways to relieve crowding are in competition: once the worst crowding is relieved, capacity is no longer a pressing concern.

This competition can include different relief lines. Big cities often have different lines that can be used to provide service to a particular area, and smaller ones that have to build a new line can have different plausible alignments for it. If one line is built or extended, the case for parallel ones weakens; only the strongest travel markets can justify multiple parallel lines.

But it can also include the conflict between building relief lines and providing extra capacity by other means, such as better signaling. The combination of conventional fixed block signaling and conventional operations is capable of moving maybe 24 trains per hour at the peak, and some systems struggle even with less – Berlin moves 18 trains per hour on the Stadtbahn, and has to turn additional peak trains at Ostbahnhof and make passengers going toward city center transfer. Even more modern signals struggle in combination with too complex branching, as in New York and some London lines, capping throughput at the same 24 trains per hour. In contrast, top-of-line driverless train signaling on captive metro lines can squeeze 42 trains per hour in Paris; with drivers, the highest I know of is 39 in Moscow, 38 on M13 in Paris, and 36 in London. Put another way, near-best-practice signaling and operations are equivalent in capacity gain to building half a line for every existing line.

Reach and convenience

In contrast with questions of capacity, questions of system convenience, accessibility, reliability, and reach show complementarity rather than competition. A rail network that is faster, more reliable, more comfortable to ride, and easier to access will attract more riders – and this generates demand for extensions, because potential passengers would be likelier to ride in such case.

In that sense, systematic improvements in signaling, network design, and accessibility do not compete with physical system expansion in the long run. A subway system with an elevator at every station, platform edge doors, and modern (ideally driverless) signaling enabling reliable operations and high average speeds is one that people want to ride. The biggest drawback of such a system is that it doesn’t go everywhere, and therefore, expansion is valuable. Expansion is even more valuable if it’s done in multiple directions – just as two parallel lines compete, lines that cross (such as a radial and a circumferential) reinforce each other through network effects.

This is equally true of buses. Interventions like bus shelter interact negatively with higher frequency (if there’s bus shelter, then the impact of wait times on ridership is reduced), but interact positively with everything else by encouraging more people to ride the bus.

The interaction between bus and rail investments is positive as well, not negative. Buses and trains don’t really compete anywhere with even quarter-decent urban rail. Instead, in such cities, buses feed trains. Bus shelter means passengers are likelier to want to ride the bus to connect the train, and this increases the effective radius of a train station, making the case for rail extensions stronger. The same is true of other operating treatments for buses, such as bus lanes and all-door boarding – bus lanes can’t make the bus fast enough to replace the subway, but do make it fast enough to extend the subway’s range.

Mainline rail investments

The biggest question in mainline rail is whether to build high-speed lines connecting the largest cities on the French or Japanese model, or to invest in more medium-speed lines to smaller cities on the German or especially Swiss model. German rail advocates assert the superiority of Germany to France as a reason why high-speed rail would detract from investments in everywhere-to-everywhere rail transport.

But in fact, those two kinds of investment complement each other. The TGV network connects most secondary cities to Paris, and this makes regional rail investments feeding those train stations stronger – passengers have more places to get to, through network effects. Conversely, if there is a regional rail network connecting smaller cities to bigger ones, then speeding up the core links gives people in those smaller cities more places to get to within two, three, four, five hours.

This is also seen when it comes to reliability. When trains of different speed classes can use different sets of track, it’s less likely that fast trains will get stuck behind slow ones, improving reliability; already Germany has to pad the intercity lines 20-25% (France: 10-14%; Switzerland: 7%). A system of passenger-dedicated lines connecting the largest cities is not in conflict with investments in systemwide reliability, but rather reinforces such reliability by removing some of the worst timetable conflicts on a typical intercity rail system in which single-speed class trains never run so often as to saturate a line.

Recommendation: invest against type

The implication of complementarity between some investment types is that a system that has prioritized one kind of investment should give complements a serious look.

For example, Berlin has barely expanded the U-Bahn in the last 30 years, but has built orbital tramways, optimized timed connections (for example, at Wittenbergplatz), and installed elevators at nearly all stations. All of these investments are good and also make the case for U-Bahn expansion stronger to places like Märkisches Viertel and Tegel.

In intercity rail, Germany has invested in medium-speed and regional rail everywhere but built little high-speed rail, while France has done the opposite. Those two countries should swap planners, figuratively and perhaps even literally. Germany should complete its network of 300 km/h lines to enable all-high-speed trips between the major cities, while France should set up frequent clockface timetables on regional trains anchored by timed connections to the TGV.

Vancouver, Stockholm, and the Suburban Metro Model

I was asked by an area advocate about SkyTrain, and this turned into a long email with various models to compare Vancouver with. In my schema contrasting suburban metro systems and S-Bahns, Vancouver is firmly in the first category: SkyTrain is not commuter rail, and Vancouver’s commuter rail system, the West Coast Express, is so weak it might as well not exist. The suburban metro model forces the region to engage in extensive transit-oriented development, which Vancouver has done. Has it been successful? To some extent, yes – Vancouver’s modal split is steadily rising, and in the 2016 census, just before the Evergreen Line opened, was 20%; supposedly it is 24% now. But it could have done better. How so?

Could Vancouver have used the S-Bahn model?

No.

There is a common line of advocacy; glimpses of it can be found on the blog Rail for the Valley, by a writer using the name Zweisystem who commented on transit blogs like Yonah and Jarrett‘s in the 2000s. Using the name of Karlsruhe’s tram-train as inspiration, Zwei has proposed that Vancouver use existing commuter rail corridors in suburban and exurban areas and streetcars in the urban core.

The problem with this is that Vancouver has very little legacy mainline rail infrastructure to work with. There are two mainlines serving city center: the Canadian Pacific, and Canadian National. The CP line hugs the coast, full of industrial customers; the CN line is farther inland and has somewhat more fixable land use, but the Millennium Line partly parallels it and even after 20 years its ridership is not the strongest in the system. Most of the urban core is nowhere near a rail mainline.

This is completely unlike the Central European S-Bahn-and-streetcars systems, all of which have legacy commuter lines radiating in all directions, and use legacy streetcars rather than newly-built light rail lines. In the last generation they’ve expanded their systems, building connections and feeding rapid transit, but none of these is a case of completely getting rid of the streetcars and then restoring them later; the busiest system that’s entirely new, that of Paris, is largely orbitals and feeders for the Métro and RER.

Vancouver did in fact reuse old infrastructure for the suburban metro concept. The Expo Line involved very little greenfield right-of-way use. Most of the core route between the historic core of Vancouver and New Westminster is in the private right-of-way of a historic BC Electric interurban; this is why it parallels Kingsway but does not run elevated over it. The tunnel in Downtown Vancouver is a disused CP tunnel; this is why the tracks are stacked one over the other rather than running side by side – the tunnel was single-track but tall enough to be cut into two levels. This limited the construction cost of the Expo Line, which the largely-elevated Millennium Line and the partly underground, partly elevated Canada Line could not match.

The Stockholm example

In my post about S-Bahns and suburban metros, I characterized Stockholm as an archetypal suburban metro. Stockholm does have an S-Bahn tunnel nowadays, but it only opened 2017, and ridership so far, while rising, is still a fraction of that of the T-bana.

Stockholm’s choice of a full metro system in the 1940s, when it had about a million people in its metro area, had its critics at the time. But there wasn’t much of a choice. The trams were fighting growing traffic congestion, to the point that some lines had to be put in a tunnel, which would later be converted for the use of the Green Line as it goes through Södermalm. Working-class housing was overcrowded and there was demand for more housing in Stockholm, which would eventually be satisfied by the Million Program.

And there were too few commuter lines for an S-Bahn system. Swedes were perfectly aware of the existence of the S-Bahn model; Berlin and Hamburg both had S-Bahns running on dedicated tracks, and Copenhagen had built its own system, called S-Tog in imitation of the German name. But they didn’t build that. None of this was the integrated Takt timetable that Munich would perfect in the 1970s, in which branches could be left single-track or shared with intercity trains provided the regular 20-minute headways could be scheduled to avoid conflicts; the track sharing required in the 1940s would have been too disruptive. Not to mention, Stockholm had too few lines, if not so few as Vancouver – only two branches on each of two sides of city center, with most of the urban core far from the train.

So Stockholm built the T-bana, with three highly branched lines all meeting at T-Centralen, the oldest two of the three having a cross-platform transfer there and at the two stations farther south. The roughly 104 km system (57 km underground) cost, in 2022 US dollars, $3.6 billion. Stockholm removed all the regular streetcars; a handful running all or mostly in private rights-of-way were retained with forced transfers at outlying T-bana stations like Ropsten, as was the narrow-gauge Roslagsbana (with a forced transfer at KTH, where I worked for two years).

At the same time the T-bana was under construction, the state built the Million Program, and in the Stockholm region, the housing projects were designed to be thoroughly oriented around the system. The pre-Million Program TOD suburb of Vällingby was envisioned as part of a so-called string of pearls, in which towns would radiate from each T-bana station, with local retail and jobs near the station surrounded by housing. In 2019, the T-bana had 1,265,900 riders per workday, Citybanan had 410,300, and the remaining lines 216,100; Sweden reports modal split for all trips and not just work trips, but the commute modal split appears to be 40% or a little higher, a figure that matches Paris, a metro area of 13 million that opened its first metro line in 1900.

So why is Stockholm better?

There are parallels between Stockholm and Vancouver – both are postwar cities with 2.5 million people in their metropolitan areas with rapid growth due to immigration. Their physical geographies are similar, with water barriers inhibiting the contiguous sprawl of many peers. Both extensively employed TOD to shape urban geography around the train: Stockholm has Vällingby and other, less famous examples of TOD; Vancouver has Metrotown and smaller examples of residential TOD along the Expo Line, alongside a famously high-rise downtown. But the T-bana has more than twice the annual ridership of SkyTrain, and Stockholm has around twice the modal split of Vancouver – this is not a matter of Canadians riding buses more than Europeans do. So what gives?

Part of it is about TOD models. Stockholm is an exceptionally monocentric city, and this has created a lot of demand for urban rail to Central Stockholm. But Vancouver’s high-rise city center has a lot of jobs, and overall, around 30% of Metro Vancouver jobs are in the city or the University Endowment Lands (that is, UBC), and the proportion of Stockholm County jobs within an equivalent area is similar. Vancouver has never built anything as massive as the Million Program, but its housing growth rate is one of the highest in the world (around 11 gross units/1,000 people per year in the 2010s), and much of that growth clusters near the Expo Line and increasingly also near the worse-developed Millennium and Canada Lines.

I suspect that the largest reason is simply the extent of the systems. SkyTrain misses the entire West Side of Vancouver west of Cambie, has poor coverage in Surrey and none in Langley, and does not cross the Burrard Inlet. The T-bana has no comparable lacunae: Roslag is served by Roslagsbanan, and the areas to be served by the under-construction extensions are all target TOD areas with much less present-day density than North Vancouver, the cores of Fairview and Kitsilano, or the town centers in Surrey other than Whalley.

What’s more, Stockholm’s construction costs may be rising but those of Vancouver (and the rest of Canada) are rising even faster and from a higher base. Nya Tunnelbanan is currently budgeted at $3.6 billion in PPP terms – 19 underground km for about the same cost as the existing 104 – but Vancouver is building half of the most critical SkyTrain extension, that under Broadway, for C$2.83 billion (US$2.253 billion in PPP terms) for just 5 km, not all underground. The projected cost per rider is still favorable, but it’s less favorable for the planned extension to Langley, and there’s no active plan for anything to the North Shore.

The silver lining for Vancouver is that the West Side is big and underdeveloped. The region has the money to extend SkyTrain not just to Arbutus as is under construction but all the way to UBC, and the entire swath of land between Central Broadway and UBC screams “redevelop me.” The current land use is a mix of mid-rise, townhouses (“missing middle”), and single-family housing; Shaughnessy, whose northern end is within a kilometer of under-construction SkyTrain stations, is single-family on large lots, and can be redeveloped as high-rise housing alongside closer-in areas. Canada does not have Europe’s allergy to tall buildings, and this is a resource that can be used to turn Vancouver into a far more transit-oriented city along the few corridors where it can afford to build. The suburban metro is always like this: fewer lines, more development intensity along them.

How Many Tracks Do Train Stations Need?

A brief discussion on Reddit about my post criticizing Penn Station expansion plans led me to write a very long comment, which I’d like to hoist to a full post explaining how big an urban train station needs to be to serve regional and intercity rail traffic. The main principles are,

  • Good operations can substitute for station size, and it’s always cheaper to get the system to be more reliable than to build more tracks in city center.
  • Through-running reduces the required station footprint, and this is one of the reasons it is popular for urban commuter rail systems.
  • The simpler and more local the system is, the fewer tracks are needed: an urban commuter rail system running on captive tracks with no sharing tracks with other traffic and with limited branching an get away with smaller stations than an intercity rail station featuring trains from hundreds of kilometers away in any direction.

The formula for minimum headways

On subways, where usually the rush hour crunches are the worst, trains in large cities run extremely frequently, brushing up against the physical limitation of the tracks. The limit is dictated by the brick wall rule, which states that the signal system must at any point assume that the train ahead can turn into a brick wall and stop moving and the current train must be able to brake in time before it reaches it. Cars, for that matter, follow the same rule, but their emergency braking rate is much faster, so on a freeway they can follow two seconds apart. A metro train in theory could do the same with headways of 15 seconds, but in practice there are stations on the tracks and dealing with them requires a different formula.

With metro-style stations, without extra tracks, the governing formula is,

\mbox{headway } = \mbox{stopping time } + \mbox{dwell time } + \mbox{platform clearing time }

Platform clearing time is how long it takes the train to clear its own length; the idea of the formula is that per the brick wall rule, the train we’re on needs to begin braking to enter the next station only after the train ahead of ours has cleared the station.

But all of this is in theory. In practice, there are uncertainties. The uncertainties are almost never in the stopping or platform clearing time, and even the dwell time is controllable. Rather, the schedule itself is uncertain: our train can be a minute late, which for our purpose as passengers may be unimportant, but for the scheduler and dispatcher on a congested line means that all the trains behind ours have to also be delayed by a minute.

What this means that more space is required between train slots to make schedules recoverable. Moreover, the more complex the line’s operations are, the more space is needed. On a metro train running on captive tracks, if all trains are delayed by a minute, it’s really not a big deal even to the control tower; all the trains substitute for one another, so the recovery can be done at the terminal. On a mainline train running on a national network in which our segment can host trains to Budapest, Vienna, Prague, Leipzig, Munich, Zurich, Stuttgart, Frankfurt, and Paris, trains cannot substitute for one another – and, moreover, a train can be easily delayed 15 minutes and need a later slot. Empty-looking space in the track timetable is unavoidable – if the schedule can’t survive contact with the passengers, it’s not a schedule but crayon.

How to improve operations

In one word: reliability.

In two words: more reliability.

Because the main limit to rail frequency on congested track comes from the variation in the schedule, the best way to increase capacity is to reduce the variation in the schedule. This, in turn, has two aspects: reducing the likelihood of a delay, and reducing the ability of a delay to propagate.

Reducing delays

The central insight about delays is that they may occur anywhere on the line, roughly in proportion to either trip time or ridership. This means that on a branched mainline railway network, delays almost never originate at the city center train station or its approaches, not because that part of the system is uniquely reliable, but because the train might spend five minutes there out of a one-hour trip. The upshot is that to make a congested central segment more reliable, it is necessary to invest in reliability on the entire network, most of which consists of branch segments that by themselves do not have capacity crunches.

The biggest required investments for this are electrification and level boarding. Both have many benefits other than schedule reliability, and are underrated in Europe and even more underrated in the United States.

Electrification is the subject of a TransitMatters report from last year. As far as reliability is concerned, the LIRR and Metro-North’s diesel locomotives average about 20 times the mechanical failure rate of electric multiple units (source, PDF-pp. 36 and 151). It is bad enough that Germany is keeping some outer regional rail branches in the exurbs of Berlin and Munich unwired; that New York has not fully electrified is unconscionable.

Level boarding is comparable in its importance. It not only reduces dwell time, but also reduces variability in dwell time. With about a meter of vertical gap between platform and train floor, Mansfield has four-minute rush hour dwell times; this is the busiest suburban Boston commuter rail station at rush hour, but it’s still just about 2,000 weekday boardings, whereas RER and S-Bahn stations with 10 time the traffic hold to a 30-second standard. This also interacts positively with accessibility: it permits passengers in wheelchairs to board unaided, which both improves accessibility and ensures that a wheelchair user doesn’t delay the entire train by a minute. It is fortunate that the LIRR and (with one peripheral exception) Metro-North are entirely high-platform, and unfortunate that New Jersey Transit is not.

Reducing delay propagation

Even with reliable mechanical and civil engineering, delays are inevitable. The real innovations in Switzerland giving it Europe’s most reliable and highest-use railway network are not about preventing delays from happening (it is fully electrified but a laggard on level boarding). They’re about ensuring delays do not propagate across the network. This is especially notable as the network relies on timed connections and overtakes, both of which require schedule discipline. Achieving such discipline requires the following operations and capital treatments:

  • Uniform timetable padding of about 7%, applied throughout the line roughly on a one minute in 15 basis.
  • Clear, non-discriminatory rules about train priority, including a rule that a train that’s more than 30 minutes loses all priority and may not delay other trains at junctions or on shared tracks.
  • A rigid clockface schedule or Takt, where the problem sections (overtakes, meets, etc.) are predictable and can receive investment. With the Takt system, even urban commuter lines can be left partly single-track, as long as the timetable is such that trains in opposite directions meet away from the bottleneck.
  • Data-oriented planning that focuses on tracing the sources of major delays and feeding the information to capital planning so that problem sections can, again, receive capital investment.
  • Especial concern for railway junctions, which are to be grade-separated or consistently scheduled around. In sensitive cases where traffic is heavy and grade separation is too expensive, Switzerland builds pocket tracks at-grade, so that a late train can wait for a slot without delaying cross-traffic.

So, how big do train stations need to be?

A multi-station urban commuter rail trunk can get away with metro-style operations, with a single station track per approach track. However, the limiting factor to capacity will be station dwell times. In cases with an unusually busy city center station, or on a highly-interlinked regional or intercity network, this may force compromises on capacity.

In contrast, with good operations, a train station with through-running should never need more than two station tracks per approach track. Moreover, the two station tracks that each approach track splits into should serve the same platform, so that if there is an unplanned rescheduling of the train, passengers should be able to use the usual platform at least. Berlin Hauptbahnhof’s deep tracks are organized this way, and so is the under-construction Stuttgart 21.

Why two? First, because it is the maximum number that can serve the same platform; if they serve different platforms, it may require lengthening dwell times during unscheduled diversions to deal with passenger confusion. And second, because every additional platform track permits, in theory, an increase in the dwell time equal to the minimum headway. The minimum headway in practice is going to be about 120 seconds; at rush hour Paris pushes 32 trains per hour on the shared RER B and D trunk, which is not quite mainline but is extensively branched, but the reliability is legendarily poor. With a two-minute headway, the two-platform track system permits a straightforward 2.5-minute dwell time, which is more than any regional railway needs; the Zurich S-Bahn has 60-second dwells at Hauptbahnhof, and the Paris RER’s single-level trains keep to about 60 seconds at rush hour in city center as well.

All of this is more complicated at a terminal. In theory the required number of tracks is the minimum turn time divided by the headway, but in practice the turn time has a variance. Tokyo has been able to push station footprint to a minimum, with two tracks at Tokyo Station on the Chuo Line (with 28 peak trains per hour) and, before the through-line opened, four tracks on the Tokaido Main Line (with 24). But elsewhere the results are less optimistic; Paris is limited to 16-18 trains per hour at the four-track RER E terminal at Saint-Lazare.

At Paris’s levels of efficiency, which are well below global best practices, an unexpanded Penn Station without through-running would still need two permanent tracks for Amtrak, leaving 19 tracks for commuter traffic. With the Gateway tunnel built, there would be four two-track approaches, two from each direction. The approaches that share tracks with Amtrak (North River Tunnels, southern pair of East River Tunnels) would get four tracks each, enough to terminate around 18 trains per hour at rush hour, and the approaches that don’t would get five, enough for maybe 20 or 22. The worst bottleneck in the system, the New Jersey approach, would be improved from today’s 21 trains per hour to 38-40.

A Penn Station with through-running does not have the 38-40 trains per hour limit. Rather, the approach tracks would become the primary bottleneck, and it would take an expansion to eight approach tracks on each side for the station itself to be at all a limit.

Watch Our Webinar on Construction Costs Tomorrow

The Italy case, done by Marco Chitti, is up on the website. I encourage people to read the entire report on how Italy has set things up in the last 20-30 years so as to have one of the lowest-cost urban rail infrastructure programs in the world. The Turkey case, by Elif Ensari, will be up shortly.

This is leading to a webinar, to be done tomorrow at 16:00 my time, 10:00 New York time, in which Marco and Elif will present their cases to the general public. I encourage people to register; you’ll be able to ask us questions and we’ll answer in chat or on video. But if you can’t make it, it will be recorded.

Systemic Investments in the New York City Subway

Subway investments can include expansion of the map of lines, for example Second Avenue Subway; proposals for such extensions are affectionately called crayon, a term from London Reconnections that hopped the Pond. But they can also include improvements that are not visible as lines on a map, and yet are visible to passengers in the form of better service: faster, more reliable, more accessible, and more frequent.

Yesterday I asked on Twitter what subway investments people think New York should get, and people mostly gave their crayons. Most people gave the same list of core lines – Second Avenue Subway Phase 2, an extension of the 2 and 5 on Nostrand, an extension of the 4 on Utica, an extension of the N and W to LaGuardia, the ongoing Interborough Express proposal, and an extension of Second Avenue Subway along 125th – but beyond that there’s wide divergence and a lot of people argue over the merits of various extensions. But then an anonymous account that began last year and has 21 followers and yet has proven extremely fluent in the New York transit advocacy conversation, named N_LaGuardia, asked a more interesting question: what non-crayon systemic investments do people think the subway needs?

On the latter question, there seems to be wide agreement among area technical advocates, and as far as I can tell the main advocacy organizations agree on most points. To the extent people gave differing answers in N_LaGuardia’s thread, it was about not thinking of everything at once, or running into the Twitter character limit.

It is unfortunate that many of these features requiring capital construction run into the usual New York problem of excessive construction costs. The same institutional mechanisms that make the region incapable of building much additional extension of the system also frustrate systemwide upgrades to station infrastructure and signaling.

Accessibility

New York has one of the world’s least accessible major metro systems, alongside London and (even worse) Paris. In contrast, Berlin, of similar age, is two-thirds accessible and planned to reach 100% soon, and the same is true of Madrid; Seoul is newer but was not built accessible and retrofits are nearly complete, with the few remaining gaps generating much outrage by people with disabilities.

Unfortunately, like most other forms of capital construction in New York, accessibility retrofits are unusually costly. The elevator retrofits from the last capital plan were $40 million per station, and the next batch is in theory $50 million, with the public-facing estimates saying $70 million with contingency; the range in the European cities with extensive accessibility (that is, not London or Paris) is entirely single-digit million. Nonetheless, this is understood to be a priority in New York and must be accelerated to improve the quality of universal design in the system.

Platform screen doors

The issue of platform screen doors (PSDs) or platform edge doors (PEDs) became salient earlier this year due to a much-publicized homicide by pushing a passenger onto a train, and the MTA eventually agreed to pilot PSDs at three stations. The benefits of PSDs are numerous, including,

  • Safety – there are tens of accident and suicide deaths every year from falling onto tracks, in addition to the aforementioned homicide.
  • Greater accessibility – people with balance problems have less to worry about from falling onto the track.
  • Capacity – PSDs take up platform space but they permit passengers to stand right next to them, and the overall effect is to reduce platform overcrowding at busy times.
  • Air cooling – at subway stations with full-height PSDs (which are rare in retrofits but I’m told exist in Seoul), it’s easier to install air conditioning for summer cooling.

The main difficulty is that PSDs require trains to stop at precise locations, to within about a meter, which requires signaling improvements (see below). Moreover, in New York, trains do not yet have consistent door placement, and the lettered lines even have different numbers of doors sometimes (4 per car but the cars can be 60′ or 75′ long) – and the heavily interlined system is such that it’s hard to segregate lines into captive fleets.

But the biggest difficulty, as with accessibility, is again the costs. In the wake of public agitation for PSDs earlier this year, the MTA released as 2019 study saying only 128 stations could be retrofitted with PSDs, at a cost of $7 billion each, or $55 million per station; in Paris, PSDs are installed on Métro lines as they are being automated, at a cost of (per Wikipedia) 4M€ per station of about half the platform length as in New York.

Signaling improvements

New York relies on ancient signaling for the subway. This leads to multiple problems: maintenance is difficult as the international suppliers no longer make the required spare parts; the signals are designed around the performance specs of generations-old trains and reduce capacity on more modern trains; the signals are confusing to drivers and therefore trains run slower than they can.

To modernize them, New York is going straight to the most advanced system available: CBTC, or communications-based train control, also known as moving-block signaling. This is already done on the L and 7 trains and is under installation on other lines, which are not isolated from the rest of the system. CBTC permits much higher peak capacity in London; in New York, unfortunately, this effect has been weaker because of other constraints, including weak electrical substation capacity and bumper tracks at the terminals of both the L and the 7.

Moreover, in New York, the L train’s performance was derated when CBTC was installed, to reduce brake wear. The effect of such computer control should be the opposite, as computers drive more precisely than humans: in Paris, the automation of Line 1 led to a speed increase of 15-20%, and CBTC even without automation has the same precision level as full automation.

As before, costs form a major barrier. I can’t give the most recent analogs, because such projects tend to bundle a lot of extras, such as new trainsets and PSDs in Paris. In Nuremberg, the first city in the world to permanently convert a preexisting metro system to driverless operations, the cost of just the driverless system is said to have been 110M€ in the late 2000s, for what I believe is 13 km of U2 (U3 was built with driverless operations in mind, and then U2, from which it branches, was converted). It is said that automating U1 should cost 100M€ for 19.5 km, but this project is not happening due to stiff competition for federal funds and therefore its real cost is uncertain. In contrast, Reinvent Albany quotes $636 million for the 7 train in New York, of which $202 million must be excluded as rolling stock conversion; the Flushing Line is 16 km long, so this is still $27 million/km and not the $7-12 million/km of Nuremberg.

Maintenance regime

The maintenance regime in New York involves heavy slowdowns and capacity restrictions. Trains run 24/7 without any breaks for regular maintenance. Instead, maintenance is done one track at a time during off-peak periods, with flagging rules that slow down trains on adjacent tracks and have gotten more onerous over the last 10-20 years; only recently have planners begun to use temporary barriers to reduce the burden of flagging.

The result of this system is threefold. First, track maintenance productivity is extremely low – the train on an adjacent track slows down as it passes but the work stops as it passes as well. Second, speeds are unreliable off-peak and the timetable is in perpetual firefighting mode. And third, parts of the system are claimed to be incapable of running more than about 16 trains per hour off-peak, which means that if there is any branching, the branches are limited to 8, which is not enough frequency on a major urban metro system.

It takes a small amount of capital spending to increase efficiency of maintenance, through procuring more advanced machinery, installing barriers between tracks, and installing crossovers at appropriate locations. But it takes a large degree of operations and management reform to get there, which is necessary for reducing the high operating costs of the subway.

Deinterlining

New York has the most complicated interlining of any global metro network. Only four lines – the 1, 6, 7, and L – run by themselves without any track sharing with other lines. The 2, 3, 4, and 5 share tracks with one another. Then the lettered trains other than the L all share tracks on various segments, without any further segregation. Only some commuter rail networks are more complex than this – and even Tokyo has greater degree of segregation between different trunk lines, despite extensive through-service to commuter rail. The New York way guarantees more direct service on more origin-destination pairs, but at low frequency and with poor speed and reliability.

London, the second most interlined system, has long wanted to reduce interlining to increase capacity. The Northern line traditionally had just one southern segment reverse-branching to two central trunks, combining and splitting into two northern branches. When CBTC opened, the busier of the central trunks got 26 peak trains per hour; the more recent Battersea extension removed the interlining to the south, permitting boosting capacity up to 32 tph, and full deinterlining to the north would boost it to 36 tph, as on the most captive Underground lines.

In New York, it is desirable to remove all reverse-branching. At DeKalb Avenue in Downtown Brooklyn, the interlocking switches the four express (bridge) tracks from an arrangement of the B and D on one track pair and the N and Q on the other to the B and Q on one track pair and the D and N on the other; the process is so complex that every train is delayed two minutes just from the operation of the switches. Everywhere within the system, interlining creates too much dependency between the different trains, so that delays on one line propagate to the others, reducing reliability, speed, and capacity.

Some of the problem is, as usual, about high costs. Rogers Avenue Junction controls the branching of the 2, 3, 4, and 5 trains in Brooklyn, transitioning from the 2 and 3 sharing one track pair and the 4 and 5 sharing another to the 3 and 4 running on dedicated tracks and the 2 and 5 sharing tracks. For a brief segment, the 2, 3 and 5 trains all share tracks. This devastates capacity on both trunk lines, which rank first and third citywide in peak crowding as of the eve of the opening of Second Avenue Subway. There are already internal designs for rebuilding the junction to avoid this problem – at a cost of $300 million.

But some of the problem is also about operating paradigms. New York must move away from the scheduling ideas of the 1920s and 30s and understand that independently-operated lines with dedicated fleets and timetables, with passengers making transfers as appropriate, are more robust and overall better for most riders. DeKalb can be deinterlined with no capital spending at all, and so can Columbus Circle. It’s Rogers and Queens Plaza where spending is ideal (but even then, not strictly required if some operational compromises are made), and the 142nd Street Junction in Harlem where an extensive rebuild is obligatory in order to permit splitting the 2 from the 5 in the Bronx permanently.

Labor changes

Staffing levels in New York are very high. Trains have conductors and not just drivers; this is not globally unheard of (Toronto and some lines in Tokyo still have conductors) but it’s rare. With good enough signaling, a retrofit even for full automation is possible, as in Nuremberg, Paris, and Singapore. Maintenance work is likewise unproductive, not because people don’t work hard, but because they work inefficiently.

Improving this situation involves changes on both sides of the ledger – staffing and service. Conductors have to be cut for efficiency and not all of them can be absorbed by other roles, and the same is true of some station facilities and maintenance functions. In contrast, the low productivity of drivers in New York – they spend around 550 hours a year driving a revenue train whereas Berlin’s drivers, who get 6 weeks of annual paid vacation, scratch 900 – is the result of poor off-peak frequency, and must be resolved through increases in off-peak service that increase efficiency without layoffs.

Ultimate goal: six-minute service

I wrote two years ago about what it would take to ensure every public transit service in New York runs every six minutes off-peak, calling it a six-minute city.

Riders Alliance argues for the same goal, with the hashtag #6minuteservice; I do not know if they were basing this on what I’d written or if it’s convergent evolution. But it’s a good design goal for timetabling, with implications for labor efficiency, maintenance efficiency, the schedule paradigm, and the bus system.

No tradeoffs

It is fortunate that the agenda of systemwide improvements does not exhibit significant tradeoffs in investment. Other parts of the transit agenda do not need to suffer to implement those improvements. On the contrary, they tend to interact positively: accessibility and PSDs can be combined (and federal law is written in such a way that PSDs void the grandfather clause permitting the subway to keep most of its stations inaccessible), faster and more reliable trains can be run more frequently off-peak, better service means higher ridership and therefore higher demand for extensions. Only the issue of labor exhibits a clear set of losers from the changes, and those can be compensated in a one-time deal.

Moreover, the budget for such an agenda is reasonable, if New York can keep its construction costs under control. At the per-elevator costs of Berlin or Madrid, New York could make its entire network wheelchair-accessible for around $3.5-4 billion. Parisian PSDs, pro-rated to the greater size of New York trains, would be around $10 million a station, or $5 billion systemwide. Full automation at German costs would be maybe $6 billion with triple- and quad-track lines pro-rated. The entire slate of changes required for full deinterlining, including a pocket track for the 3 train at 135th Street, a rebuild of the 36th Street station in Queens, and a connection between Queensboro Plaza and Queens Plaza, should be measured in the hundreds of millions, not billions.

The overall program still goes into double-digit billions; it requires a big push. But this big push is worth two to three years’ worth of current New York City Transit capital spending. A New York that can do this can also add 50-100 km to its subway network and vice versa, all while holding down operating costs to typical first-world levels. For the most part, the planners already know what needs to be done; the hard part is getting construction costs to reasonable levels so that they can do it on the current budget.

Tails on Commuter Rail

An interesting discussion on Twitter came out of an alternatives analysis for Philadelphia commuter rail improvements. I don’t want to discuss the issue at hand for now (namely, forced transfers), but the discussion of Philadelphia leads to a broader question about tails. Commuter rail systems sometimes have low-frequency tails with through-service to the core system and sometimes don’t, and it’s useful to understand both approaches.

What is a tail?

For the purposes of this post, a tail is whenever there is a frequent line with trains infrequently continuing farther out. Frequency here is relative, so a subway line running every 2.5 minutes to a destination with every fourth train continuing onward is a tail even though the tail still has 10-minute frequency, and a commuter line running every 20 minutes with every third train continuing onward also has a tail, even though in the latter case the core frequency is lower than the tail frequency in the former case.

The key here is that the line serves two markets, one high-intensity and frequent and one lower-intensity warranting less service, with the outer travel market running through to the inner one. Usually the implication is that the inner segment can survive on its own and the contribution of the outer segment to ridership is not significant by itself. In contrast, it’s common enough on S-Bahn systems to have a very frequent trunk (as in Berlin, or Munich, or Paris) that fundamentally depends on through-service from many suburban segments farther out combining to support high frequency in the core; if ridership farther out is significant enough that without it frequency in the core would suffer, I would not call this a tail.

When are tails useful?

Tails are useful whenever there is a core line that happens to be along the same route as a lower-intensity suburban line. In that case, the suburban line behind can benefit from the strong service in the core by having direct through-service to it at a frequency that’s probably higher than it could support by itself. This is especially valuable as the ridership of the tail grows in proportion to that of the core segment – in the limiting case, it’s not even a tail, just outer branches that combine to support strong core frequency.

Tokyo makes extensive use of tails. The JR East commuter lines all have putative natural ends within the urban area. For example, most Chuo Rapid Line trains turn at Takao, at the western end of the built-up area of Tokyo – but some continue onward to the west, running as regional trains to Otsuki or as interregional or as intercity trains farther west to Shiojiri.

Munich and Zurich both use tails as well on their S-Bahns. In Munich, the base frequency of each of the seven main services is every 20 minutes, but some have tails running hourly, and all have tails running two trains per hour with awkward alternation of 20- and 40-minute gaps. In Zurich, the system is more complex, and some lines have tails (for example, S4) and some do not (for example, S3); S4 is not a portion of an intercity line the way the Chuo Line is, and yet its terminus only gets hourly trains, while most of the line gets a train every 20 minutes.

What are the drawbacks of tails?

A tail is a commitment to running similar service as in the core, just at lower frequency. In Philadelphia, the proposal to avoid tails and instead force what would be tails into off-peak shuttle trains with timed transfers to the core system is bundled into separate brands for inner and outer service and a desire to keep the outer stations underbuilt, without accessibility or high platforms. Branding is an exercise in futility in this context, but there are, in other places than Philadelphia, legitimate reasons to avoid tails, as in Paris and Berlin:

  • Different construction standards – perhaps the core is electrified and an outer segment is not; historically, this was the reason Philadelphia ended commuter rail service past the limit of electrification, becoming the only all-electrified American commuter rail network. In Berlin, the electrification standards on the mainline and on the S-Bahn differ as the S-Bahn was electrified decades earlier and is run as an almost entirely self-contained system.
  • Train size difference – sometimes the gap in demand is such that the tail needs not just lower frequency than the core but also shorter trains. In the United States, Trenton is a good example of this – New York-Trenton is a much higher-demand line than Trenton-Philadelphia and runs longer trains, which is one reason commuter trains do not run through.
  • Extra tracks – if there are express tracks on the core segment, then it may be desirable to run a tail express, if it is part of an intercity line like the Chuo Line rather than an isolated regional line like S4 in Zurich, and not have it interface with the core commuter line at all to avoid timetabling complications. If there are no extra tracks, then the tail would have to terminate at the connection point with the core line, as is proposed in Philadelphia, and the forced transfer is a drawback that generally justifies running the tail.

Do the drawbacks justify curtailment?

Not really. On two-track lines, it’s useful to provide service into city center from the entire line, just maybe not at high frequency on outer segments. This can create situations in which intercity-scale lines run as commuter rail lines that keep going farther than typical, and this is fine – the JR East lines do this on their rapid track pairs and within the built-up area of Tokyo people use those longer-range trains in the same way they would an ordinary rapid commuter train.

This is especially important to understand in the United States, which is poor in four-track approaches of the kind that the largest European cities have. I think both Paris and Berlin should be incorporating their regional lines into the core RER and S-Bahn as tails, but they make it work without this by running those trains on dedicated tracks shared with intercity service but not commuter rail. Boston, New York, and Philadelphia do not have this ability, because they lack the ability to segregate S-Bahn and RegionalBahn services. This means Boston should be running trains to Cape Cod, Manchester, and Springfield as tails of the core system, and New York should electrify its entire system and run trains to the Hamptons as LIRR tails, and Philadelphia should run tail trains to the entire reach of its commuter rail system.

How to Spend Money on Public Transport Better

After four posts about the poor state of political transit advocacy in the United States, here’s how I think it’s possible to do better. Compare what I’m proposing to posts about the Green Line Extension in metro Boston, free public transport proposals, federal aid to operations, and a bad Green New Deal proposal by Yonah Freemark.

If you’re thinking how to spend outside (for example, federal) money on local public transportation, the first thing on your mind should be how to spend for the long term. Capital spending that reduces long-term operating costs is one way to do it. Funding ongoing operating deficits is not, because it leads to local waste. Here are what I think some good guidelines to do it right are.

Working without consensus

Any large cash infusion now should work with the assumption that it’s a political megaproject and a one-time thing; it may be followed by other one-time projects, but these should not be assumed. High-speed rail in France, for example, is not funded out of a permanent slush fund: every line has to be separately evaluated, and the state usually says yes because these projects are popular and have good ROI, but the ultimate yes-no decision is given to elected politicians.

It leads to a dynamic in which it’s useful to invest in the ability to carry large projects on a permanent basis, but not pre-commit to them. So every agency should have access to public expertise, with permanent hires for engineers and designers who can if there’s local, state, or federal money build something. This public expertise can be in-house if it’s a large agency; smaller ones should be able to tap into the large ones as consultants. In France, RATP has 2,000 in-house engineers, and it and SNCF have the ability to build large public transport projects on their own, while other agencies serving provincial cities use RATP as a consultant.

It’s especially important to retain such planning capacity within the federal government. A national intercity rail plan should not require the use of outside consultants, and the federal government should have the ability to act as consultant to small cities. This entails a large permanent civil service, chosen on the basis of expertise (and the early permanent hires are likely to have foreign rather than domestic experience) and not politics, and yet the cost of such a planning department is around 2 orders of magnitude less than current subsidies to transit operations in the United States. Work smart, not hard.

However, investing in the ability to build does not mean pre-committing to build with a permanent fund. Nor does it mean a commitment to subsidizing consumption (such as ongoing operating costs) rather than investment.

Funding production, not consumption

It is inappropriate to use external infusions of cash for operations and, even worse, maintenance. When maintenance is funded externally, local agencies react by deferring maintenance and then crying poverty whenever money becomes available. Amtrak fired David Gunn when the Bush administration pressured it to defer maintenance in order to look profitable for privatization and replaced him with the more pliable Joe Boardman, and then when the Obama stimulus came around Boardman demanded billions of dollars for state of good repair that should have built a high-speed rail program instead.

This is why American activists propose permanent programs – but those get wasted fast, due to surplus extraction. A better path forward is to be clear about what will and will not be funded, and putting state of good repair programs in the not-funded basket; the Bipartisan Infrastructure Framework’s negotiations were right to defund the public transit SOGR bucket while keeping the expansion bucket.

Moreover, all funding should be tied to using the money prudently – hence the production, not consumption part. This can be capital funding, with the following priorities, in no particular order:

  • Capital funding that reduces long-term operating costs, for example railway electrification and the installation of overhead wires (“in-motion charging“) on bus trunks.
  • Targeted investments that improve the transit experience. Bus shelter is extremely cost-effective on this point and a federal program to fund it at a level of around $15,000/stop (not more – it’s easy to make local demands that drive it up to $50,000) would have otherworldly social rates of return. Washington bureaucrats are loath to be this explicit about what to do – they try to speak in circumlocutions, saying “standards for bus stops” instead of just funding shelter, or “transit asset management” instead of just committing to not playing the SOGR game.
  • Accessibility upgrades. This require close federal control to eliminate local waste, because much of the money would be going to New York, which has a long-term problem of siphoning accessibility money to other priorities like adding station access points or repairing stations, and has a uniquely incompetent local environment when it comes to construction costs.
  • Planning aid for improving bus-rail interface; these two modes are often not planned together in American cities, and commuter rail is not planned in conjunction with other modes. San Jose, for example, has a proposal for large expansion of bus service, part of which is parallel to Caltrain; the local agency, VTA, owns one third of Caltrain and could expand rail service within the county and integrate it with bus service better, but does not do so.
  • Rail automation, to reduce long-term operating costs. Bus automation could go in this bucket too but is at this point too speculative; save it for one or two stimuli in the future.

Avoiding local extraction

Local government has very little democratic legitimacy. It’s based on informal power arrangements, in which direct elections play little role; partisan elections are rare and instead primaries reign with severe democratic deficits (for example, it’s hard to form any kind of base for opposition to challenge a sitting New York mayor or governor). Without national ideology to guide it, it is the domain of cranks and people with the time and leisure to attend community meetings on weekdays at 3 pm. Local community takes its illegitimate power and thieves what others create, whether it is the market or the state.

Recognizing this pattern means that federal funding should not under any circumstances coddle local arrangements. If, for example, California cannot spend money cost-effectively because it is constrained by referendum, federal funding can be used to bypass this system, but never work under its rules. If the local business community is traumatized by cut-and-cover construction in the distant past, the feds should insist that subway money that they give will be used for cut-and-cover instead of mined stations.

The typical surplus extraction pattern concerns car dominance. State DOTs are in effect highway departments; transit planning is siloed, usually at separate agencies. They use their power to demand the diversion of transit money to roads. For example, in Tampa, a plan to increase bus service led to a DOT demand to pave the routes with concrete lanes at transit agency expense (with federal or state transit funding). The list of BRT projects that were just highway widenings is regrettably too long. The feds should actively demand to keep transit funding for transit, and not roads, social services, policing, or other priorities.

In particular, the feds should give money for some bus improvements, but demand that agencies prioritize the bus over the car. No bus lanes? No signal priority? No money. Similarly, they should demand they engage in internal efficiency measures like stop consolidation and all-door boarding with proof of payment ticket collection, which a larger and more expert FTA can give technical assistance for.

It may also be prudent to give transitional resources, up to a certain point. Funding private-sector retraining for workers displaced by automation is good, and in some limited cases public-sector retraining, as long as it doesn’t turn into workfare (there is no way for the subway in New York to absorb redundant conductors or surplus maintenance staff). If moderate amounts of capital funding are required for bus improvements, such as traffic signal upgrades to have active control and conditional TSP, then they are good investments as well.

Conclusion

Funding public transportation is useful, provided there is enough of a connection between the source of funds and the management thereof that the money is not wasted. A larger and more technocratic federal government is an ideal organ for this, with enough planning power to propose bus network redesigns, rail planning, integrated fare systems, and intermodal coordination. It can and should have technical priorities – shelter is far and away the lowest-hanging fruit for American bus systems – and state them clearly rather than hiding behind bureaucratic phrases (again, “transit asset management” is a real phrase).

It’s fundamentally an investment rather than consumption. And as with all investments, it’s important to ensure one invests in the right thing and the right people. A local transit agency with a track record of successful projects, short lead times from planning to completion, technical orientation, and the ability to say no to highway departments and other organs that extract surplus is a good investment. One that instead genuflects before antisocial groups that launch nuisance lawsuits is not so good an investment, and funding for such an agency should be contingent on improvement in governance of the kind that will make local notables angry.