Category: Urban Transit

In-Motion Charging

While electric cars remain a niche technology, electric buses are surging. Some are battery-electric (this is popular in China, and some North American agencies are also buying into this technology), but in Europe what’s growing is in-motion charging, or IMC. This is a hybrid of a trolleybus and a battery-electric bus (BEB): the bus runs under wire, but has enough battery to operate off-wire for a little while, and in addition has some mechanism to let the bus recharge during the portion of its trip that is electrified.

One vendor, Kiepe, lists recent orders. Esslingen is listed as having 10 km of off-wire capability and Geneva (from 2012) as having 7. Luzern recently bought double-articulated Kiepe buses with 5 km of off-wire range, and Linz bought buses with no range specified but of the same size and battery capacity as Luzern’s. Iveco does not specify what its range is, but says its buses can run on a route that’s 25-40% unwired.

Transit planning should be sensitive to new technology in order to best integrate equipment, infrastructure, and schedule. Usually this triangle is used for rail planning, but there’s every reason to also apply it to buses as appropriate. This has a particular implication to cities that already have large trolleybus networks, like Vancouver, but also to cities that do not. IMC works better in some geographies than others; where it works, it is beneficial for cities to add wire as appropriate for the deployment of IMC buses.

Vancouver: what to do when you’re already wired

Alert reader and blog supporter Alexander Rapp made a map of all trolleybus routes in North America. They run in eight cities: Boston, Philadelphia, Dayton, San Francisco, Seattle, Vancouver, Mexico City, Guadalajara.

Vancouver’s case is the most instructive, because, like other cities in North America, it runs both local and rapid buses on its trunk routes. The locals stop every about 200 meters, the rapids every kilometer. Because conventional trolleybuses cannot overtake other trolleybuses, the rapids run on diesel even on wired routes, including Broadway (99), 4th Avenue (44, 84), and Hastings (95, 160), which are in order the three strongest bus corridors in the area. Broadway has so much ridership that TransLink is beginning to dig a subway under its eastern half; however, the opening of the Broadway subway will not obviate the need for rapid buses, as it will create extreme demand for nonstop buses from the western end of the subway at Arbutus to the western end of the corridor at UBC.

IMC is a promising technology for Vancouver, then, because TransLink can buy such buses and then use their off-wire capability to overtake locals. Moreover, on 4th Avenue the locals and rapids take slightly different routes from the western margin of the city proper to campus center, so IMC can be used to let the 44 and 84 reach UBC on their current route off-wire. UBC has two separate bus loops, one for trolleys and one for diesel buses, and depending on capacity IMC buses could use either.

On Hastings the situation is more delicate. The 95 is not 25-40% unwired, but about 60% unwired – and, moreover, the unwired segment includes a steep mountain climb toward SFU campus. The climb is an attractive target for electrification because of the heavy energy consumption involved in going uphill: at 4 km, not electrifying it would brush up against the limit of Kiepe’s off-wire range, and may well exceed it given the terrain. In contrast, the 5 km in between the existing wire and the hill are mostly flat, affording the bus a good opportunity to use its battery.

Where to add wire

In a city without wires, IMC is the most useful when relatively small electrification projects can impact a large swath of bus routes. This, in turn, is most useful when one trunk splits into many branches. Iveco’s requirement that 60-75% of the route run under wire throws a snag, since it’s much more common to find trunks consisting of a short proportion of each bus route than ones consisting of a majority of route-length. Nonetheless, several instructive examples exist.

In Boston, the buses serving Dorchester, Mattapan, and Roxbury have the opportunity to converge to a single trunk on Washington Street, currently hosting the Silver Line. Some of these buses furthermore run on Warren Street farther south, including the 14, 19, 23, and 28, the latter two ranking among the MBTA’s top bus routes. The area has poor air quality and high rates of asthma, making electrification especially attractive.

Setting up wire on Washington and Warren Streets and running the Silver Live as open BRT, branching to the south, would create a perfect opportunity for IMC. On the 28 the off-wire length would be about 4.5 km each way, at the limit of Kiepe’s capability, and on the 19 and 23 it would be shorter; the 14 would be too long, but is a weaker, less frequent route. If the present-day service pattern is desired, the MBTA could still electrify to the northern terminus of these routes at Ruggles, but it would miss an opportunity to run smoother bus service.

In New York, there are examples of trunk-and-branch bus routes in Brooklyn and Queens. The present-day Brooklyn bus network has a long interlined segment on lower Fulton, carrying not just the B25 on Fulton but also the B26 on Halsey and B52 on Gates, and while Eric Goldwyn’s and my plan eliminates the B25, it keeps the other two. The snag is that the proportion of the system under wire is too short, and the B26 has too long of a tail (but the B52 and B25 don’t). The B26 could get wire near its outer terminal, purposely extended to the bus depot; as bus depots tend to be polluted, wire there is especially useful.

More New York examples are in Queens. Main Street and the Kissena-Parsons corridor, both connecting Flushing with Jamaica, are extremely strong, interlining multiple buses. Electrifying these two routes and letting buses run off-wire on tails to the north, reaching College Point and perhaps the Bronx on the Q44 with additional wiring, would improve service connecting two of Queens’ job centers. Moreover, beyond Jamaica, we see another strong trunk on Brewer Boulevard, and perhaps another on Merrick (interlining with Long Island’s NICE bus).

Finally, Providence has an example of extensive interlining to the north, on North Main and Charles, including various 5x routes (the map is hard to read, but there are several routes just west of the Rapid to the north).

IMC and grids

The examples in New York, Providence, and Boston are, not coincidentally, ungridded. This is because IMC interacts poorly with grids, and it is perhaps not a coincidence that the part of the world where it’s being adopted the most has ungridded street networks. A bus grid involves little to no interlining: there are north-south and east-west arterials, each carrying a bus. The bus networks of Toronto, Chicago, and Los Angeles have too little interlining for IMC to be as cost-effective as in New York or Boston.

In gridded cities, IMC is a solution mainly if there are problematic segments, in either direction. If there’s a historic core where wires would have adverse visual impact, it can be left unwired. If there’s a steep segment with high electricity consumption, it should be wired preferentially, since the cost of electrification does not depend on the street’s gradient.

Overall, this technology can be incorporated into cities’ bus design. Grids are still solid when appropriate, but in ungridded cities, trunks with branches are especially attractive, since a small amount of wire can convert an entire swath of the city into pollution-free bus operation.

New York City Subway Expansion Proposal

I wrote a post proposing disentangling the subway in New York a few months ago. On the same basis, I’ve drawn some extra lines that I think should be built in the event the region can get its construction costs under control:

A higher-resolution image (warning: 52 MB) can be found here. The background image is taken from OpenStreetMap. Python 2.7 code for automatically downloading tiles and pasting them into a single image can be found here. Make sure you get PIL or else the paste.py file won’t run; first run tiles.py, and choose whichever tiles you’d like (the boundaries I used for this image are given in the paste.py code as x1, x2, y1, y2), and then run paste.py, changing the x1, x2, y1, y2 variables in the code as needed. As a warning, pasting images together makes them much bigger – the sum of the individual tiles I used is 15 MB but pasted together they became 46 MB.

Legend

Local stations are denoted by black circles, express stations by bigger circles with white filling. On four-track lines and three-track lines with peak-direction express trains (that is, the 2, 6, and D in the Bronx and the 7 in Queens), the local/express designation is straightforward. Two-track tails are denoted as all local; for the most part the trains continue as express on the three- or four-track lines, but on the Brighton Line the expresses keep turning at Brighton Beach while the locals are the trains that go into Coney Island. On a few two-track segments stations are denotes as express and not local, for example the 2 in Harlem or the A in Lower Manhattan and Downtown Brooklyn: this occurs when a two-track line turns into a three- or four-track line farther out, so that people don’t get the impression that these are local-only stations that the express trains skip.

The local and express patterns are barely changed from today. On Eastern Parkway trains run local east of Franklin Avenue, without skipping Nostrand and Kingston-Throop as the 4 does today. Skip-stop on the J train is eliminated, as is express-running between Myrtle and Marcy Avenues. On Queens Boulevard and Central Park West, the trains serving Sixth Avenue (i.e. the orange ones) run express and the ones serving Eighth (i.e. the blue ones) run local, but I’m willing to change my mind on at least one of these two designations; on Queens Boulevard, 36th Street is also turned into an express station, so that passengers can transfer to 63rd or 53rd Street.

As far as possible, I’ve tried to be clear about which stations are connected and which aren’t. The rule is that circles that touch or are connected by a black line denote transfer stations. However, in the lower-resolution version it may hinge on a single pixel’s worth of separation in Downtown Manhattan. The only new interchanges in Downtown Manhattan connect the 1 with PATH in the Village and at World Trade Center (and the latter connection also connects to the R, E, and 2/3).

No existing subway station is slated for closure. If an existing subway station is missing a circle, it’s an error on my part. Edit: I found one mistaken deletion – the 9th Street PATH station (which should be connected with West 4th, but the West 4th circle doesn’t touch PATH).

New lines

Most of this map should be familiar to people who have followed discussions among railfans in New York (and not just myself) about the next priorities after Second Avenue Subway. Utica and Nostrand are there, with stops that match nearly all of the east-west buses. Northern Boulevard, which Yonah Freemark pointed is a denser corridor than Utica, is also there. Triboro RX is there: the route through the Bronx includes a little more tunneling to connect with the 2 train better, forced by incursions onto the right-of-way farther north. LaGuardia gets an elevated extension of the N, which I’ve periodically argued is superior to other alignments and sound in its own right. Second Avenue Subway continues west under 125th Street, providing crosstown service on a street where buses are very busy despite being slower than walking.

In New Jersey, a hefty proportion of the lines already exist, as part of PATH or the Hudson-Bergen Light Rail. PATH is completely dismembered in this proposal: the line from Newark to World Trade Center is connected with the 6 train, an idea that I don’t think is a top priority but that some area advocates (such as IRUM) have proposed; most of the rest is turned into a 7 extension and connected with the two southern HBLR branches, both of which are extended, one to Staten Island and one to Newark; what remains is reduced to a shuttle from Hoboken to Sixth Avenue. Note that the 6-PATH train also gets an infill stop at Manhattan Transfer for regional rail connections.

The other extensions come from a number of different places:

  • The 6 is extended to Co-op City, the 7 is extended to College Point, and the 1 to the edge of the city. The first two are big ridership generators, and all three also extend lines beyond their bumper tracks, increasing turnback capacity.
  • The Queens Boulevard express trains branch in Jamaica, as they do today, and both branches are extended to near city limits. The southern extension also increases turnback capacity (some E trains run to Jamaica-179th and not Jamaica Center today for this reason), but the primary purpose is to improve coverage to areas of the city that are already at worst missing middle density and redevelopable as mid-rise apartment blocks, and have very long commutes today.
  • The 1 is extended to Red Hook. This was proposed by AECOM a few years ago; my alignment differs somewhat in that it doesn’t connect Red Hook with the subway within Brooklyn, but does connect it directly with South Brooklyn, where in the event of such a subway extension a high-frequency bus (the B71) could run onward.
  • Instead of the periodically mooted 7 extension to Secaucus, the L is extended there, with a four-track tunnel under the Hudson providing for easy 7/L transfers.
  • There’s a preexisting bellmouth for connecting the C train to New Jersey across the George Washington Bridge; it is activated in this plan, with an extension to Paterson elevated over Route 4, with tunneling within Paterson itself. Route 4 is a freeway, but it’s flanked by shopping centers in Paramus, has good regional rail connections and good potential connections if the Northern Branch and West Shore Line are reactivated, and terminates in a dense working-class city.
  • The old Erie Main Line gets converted to subway operations, running elevated through the built-up area of Secaucus.
  • To connect some of the new lines to one another, two new Manhattan trunk lines, both two-track, are built: under 50th Street, and under Third Avenue, the latter substituting for phases 3 and 4 of Second Avenue Subway in order to avoid reverse-branching. Third then connects to the northern reaches of Eighth Avenue Line via a super-express line, with new stations at 110th and 125th; the alignment through Central Park is designed to allow cheap cut-and-cover construction.
  • Bergenline Avenue, where traffic fills a bus every 2 minutes, gets a subway. One station is designed for a commuter rail transfer to new Hudson tunnels with a Bergenline stop. The segment south of Journal Square is weaker and can be removed from scope, but as it can be done in an existing above-ground right-of-way, it’s also cheaper than the rest.
  • The D train gets a two-stop extension to the north to connect to Metro-North at Williams Bridge and the 2 train at Gun Hill Road.

Conspicuous absences

There is no subway connection to JFK or Newark Airport on this map. The JFK AirTrain is adequate with better regional rail and fare integration; so is a Newark connection at the current commuter rail station. A direct JFK regional rail connection may be included in a 9-line regional rail map (for reference, the map I usually peddle has 5 or 6 trunk lines, not 9). A Newark rapid transit connection may be included in a much more expansive version, but even then it’s unlikely – the only reason to build such a connection is for extra capacity, and it’s better to resolve mainline rail capacity crunches by building more mainline rail.

There is no R train to Staten Island, an extension that some railfans (including myself many years ago) periodically call for; this could be added, but is a low priority, as regional rail could provide faster service to Downtown Brooklyn with a transfer than the R train ever could.

But the biggest absence is Second Avenue Subway phases 3 and 4. Phase 3 is replaced with a subway under Third Avenue, and phase 4 is omitted entirely. The reason for this omission is, as mentioned above, to avoid reverse-branching, and permit the new system to consist of separate lines without track-sharing, which is more reliable than today’s heavily interlined system.

Phase 4 is also difficult and not all that useful. Lower Manhattan construction is sometimes necessary but should be avoided when it isn’t, as the area has narrow rights-of-way, complex underground station footprints, and archeology going back to the 17th century. There is no capacity crunch heading to Lower Manhattan – southbound trains unload in Midtown in the morning peak – and the area is so small and has so many subways that there is no coverage gap that Second Avenue Subway would fill. Even phase 3 mostly duplicates the Lexington Avenue Line, but serves a large and growing business district in East Midtown where trains do have a capacity crunch, hence the Third Avenue subway.

Scope and costs

The map has around 110 km of new subway and 100 km of new els and other open-air lines (such as the Triboro and Erie rights-of-way). Some of the subways can be built cut-and-cover given sufficient political cajoling, including Nostrand, most of Bergenline, parts of Third and Utica, Northern, and the outer Queens extension. But many cannot: there are 6 new river crossings (50th*2, 7, L, Utica, 1), a kilometer of pure pain in connecting the 6 with PATH, another PATH pain involving a new Exchange Place dig for platforms for the 7, and some new stations that have to be mined (e.g. 50th Street).

At what I consider a normal first-world cost, the tunnels would be around $25 billion in last decade’s money, so maybe $30 billion in today’s money, and the els would add around $10 billion. To put things in perspective, the current five-year MTA capital program is spending $33 billion, nearly all of which is routine maintenance. It’s affordable within a decade if the region gets its construction costs under control.

The American Way of Building Rapid Transit

I’ve sporadically discussed how some countries or regions have traditions of how to build rapid transit. For example, in a City Metric article last year I made an off-hand comment about how communist bloc metros, from Europe to North Korea, have widely-spaced stops just like Moscow, while French metros and French-influenced Montreal Metro have short stop spacing just like Paris. I intend to write some posts covering different traditions, starting from one I’ve barely discussed as such: the American one. There are commonalities to how different American cities that build subways choose to do so, usually with notable New York influences, and these in turn affect how American transit activists think about trains.

For the most part, the American tradition of rapid transit should be viewed as one more set of standards, with some aspects that are worth emulating and others that are not. Most of the problems I’ve harped on are a matter of implementation more than a matter of standards. That said, that something is the local tradition does not immediately mean it works, even if on the whole the tradition is not bad. Some of the traditions discussed below definitely increase construction costs or reduce system effectiveness.

The situation in New York

A large majority of American rapid transit ridership, about two thirds, is in New York. The city’s shadow is so long that the systems built in the postwar era, like the Washington Metro and BART, were designed with New York as a reference, whether consciously or not. Only the Boston subway and Chicago L are old enough to avoid its influence – but then their elevated system design still has strong parallels in New York, whether due to direct influence or a common zeitgeist at the end of the 19th century. Thus, the first stop on the train of thought of the American rapid transit tradition must be New York practice.

New York has nine subway main lines. Five are north-south through Manhattan and four-track, three are east-west and two-track, and one avoids Manhattan entirely. Nearly all construction was done cut-and-cover between 1900 and 1940, forcing lines to hew to the street network. As New York has wide, straight streets, a trait shared with practically all American cities, this was not a problem, unlike in London, where carving right-of-way for the Underground was so difficult that every line from the third onward was built deep-bore.

With four tracks on most of the Manhattan trunks, there is local and express service. This allows trains to go around obstacles more easily, increasing redundancy. It’s in this context that New York’s 24/7 service makes sense: there is no absolute need for nighttime maintenance windows in which no train runs. This approach works less well on the two-track lines, and the L, the only one that’s two-track the entire way, has occasional work orders with very low train frequency because of single-tracking.

Outside the core of the city as it was understood during construction, lines run elevated. The standard New York el is an all-steel structure, which reduces construction costs – the First Subway’s subway : el cost ratio was 4:1, whereas today the average is about 2.5:1 even though tunneling uses the more expensive boring technique – at the cost of creating a boombox so noisy that it’s impossible to have a conversation under the tracks while a train is passing. Moreover, splitting the difference between two and four tracks, the standard el has three tracks, which allows peak-direction express service (on the 2/5, 6, and 7) or more space for trains to get around obstacles (on the 1, 4, and N/W).

Because the els are so noisy, the city stopped building them in the 1920s. The lines built in the 1930s were all underground, with the exception of one viaduct over an industrial shipping channel.

Moreover, from the 1930s onward, stations got bigger, with full-length mezzanines (the older stations had no or short mezzanines). Track standards increased, leading to an impressive and expensive array of flying junctions, contrasting with the flat junctions that characterize some older construction like the Chicago L or some foreign examples like much of the London Underground.

Finally, while New York has nine separate subway colors, its number of named lines is far greater. The system comprises several tens of segments called lines, and each route combines different lines, with complex branching and recombination. The infrastructure was never built for discrete lines with transfers between them, but rather for everywhere-to-everywhere one-seat rides, and service choices today reinforce this, with several outer lines reverse-branching to an East Side and a West Side Manhattan trunk.

The desire for 24/7 service

I know of five urban rail networks with 24/7 service. One is the Copenhagen Metro, which is driverless and built with twin bores, making it easy for service to single-track at night for maintenance. The other four are American: the New York City Subway, PATH, PATCO, and the Chicago L. Moreover, the LIRR runs 24/7, which no other commuter rail system I know of does, even ones where an individual outlying station has comparable ridership to the entire LIRR.

The other systems have somewhat of a 24/7 envy. I’ve heard lay users and activists in Washington and the Bay Area complain that the Washington and BART shut down overnight; BART itself feels it has to justify itself to the users on this question. Right now, BART’s decision to temporarily add an hour to the nighttime shutdown window to speed up maintenance is controversial. People are complaining that service is being cut despite increases in funding. In Washington, the more professional activists understand why 24/7 service is unviable, but like BART feel like they have to explain themselves.

Local and express trains

New York is full of four-track mainlines, running both local and express trains. Chicago and Philadelphia have them as well on one line each. The other rapid transit networks in the US don’t, but like 24/7 service desire it. Washington has enough complaints about it that regular reader and Patreon supporter DW Rowlands had to write an article for Greater Greater Washington explaining why it would not be all that useful.

BART is the more interesting case. In any discussion of BART extensions, people bring up the fact that BART can’t skip stops – never mind that its stop spacing is extremely wide owing to its function as suburban rail. The average speed on BART is 57 km/h per the National Transit Database; the RER A, which is the express service here, averages around 50. At BART’s speed, the single longest express segment in New York not crossing water, the A/D between 125th and 59th Streets, would take 7 minutes; in fact it takes about 9. If anything, BART errs in having too few stations in Oakland and San Francisco.

On new-build systems, four tracks are understandable and desirable, provided the construction method is cut-and-cover, as it was in early-20th century America. The earliest subway lines built in New York had little cost premium over London and Paris even though the tunnels were twice as wide for twice as many tracks. However, cut-and-cover is no longer used in developed countries owing to its heavy impact on merchants and residents along the way; already during WW2, Chicago dug the tunnels for the Red and Blue Lines of the L using deep boring. A city that bores tunnels will find that four-track tunnels cost twice as much as two-track tunnels, so it might as well built two separate lines for better coverage.

The shadow of steel els

New York, Boston, Philadelphia, and Chicago all built all-steel els. While cheaper, these structures are so noisy that by the 1930s they became untenable even in far-out neighborhoods, like on the Queens Boulevard Line. New lines in New York were underground; existing els were removed, quickly in New York and more slowly in Boston.

The newer systems built in the US avoided els entirely. BART planned to build one in Berkeley, but community opposition led to a change to an underground alignment; unlike subsequent examples of NIMBYism, Berkeley was willing to pay the cost difference. When tunnels are infeasible due to cost, American rail networks prefer at-grade rights-of-way, especially freeway medians. Rail rights-of-way are popular where available, such as on the realigned Orange Line in Boston, but freeway medians are common where rail alignments don’t exist.

The next generation of American urban rail systems, unable to tunnel in city center, turned to light rail in order to keep things at-grade. Across the border, in Canada, Vancouver built els to cover gaps in the right-of-way that turned into the Expo Line, and then built concrete els on the Millennium Line and outer Canada Line to reinforce the system. These brutalist structures are imposing, but I’ve had conversations under the viaducts in Richmond, just as I have in Paris under the mixed concrete and steel structures or in Sunnyside next to New York’s one concrete el.

Reverse-branching

New York did not invent reverse-branching. London has had it since the 1860s, when most South London railways ran separate trains to the City (at Cannon Street, London Bridge, or Blackfriars) or the West End (at Victoria or Charing Cross), and multiple North London railways ran trains to their traditional terminals or to the North London Railway for service to Broad Street. Paris has had it since even earlier: the railways operating out of Gare Saint-Lazare and Gare Montparnasse merged in 1851 and treated the two stations as reverse-branches allowing cities farther west to access both the Right Bank and the Left Bank. In both cities, this situation makes it harder to run coherent regional rail – in London the railways are spending considerable resources on disentangling the lines to increase frequency to South London’s many branches, and in Paris the fact that Montparnasse and Saint-Lazare serve similar destinations frustrated plans to connect the two stations with an RER tunnel.

Where New York innovated is in copying this practice on rapid transit, starting with the Dual Contracts era. In Brooklyn, existing as well as new outlying lines could be routed to any number of new crossings to Manhattan; in the Bronx and Eastern Brooklyn, a desire to give branches service to both the West Side and East Side led to reverse-branching even on the numbered lines, which were built from scratch and did not involve older suburban railroads.

Reverse-branching spread across the United States. Boston had it until it removed the Atlantic Avenue El, and even today, railfans occasionally talk about reverse-branching the Red Line along Massachusetts Avenue to Back Bay and Roxbury. Chicago occasionally has it depending on the arrangement of trains on the North Side; today, the Purple and Brown Lines share tracks at rush hour but then go in opposite directions on the Loop. The Broad Street Line in Philadelphia reverse-branches to Chinatown. The Washington Metro has reverse-branches in Virginia, limiting train frequency due to asymmetry at the merge points. BART designed itself to force a three-way wye in Oakland pointing toward San Francisco, Berkeley and Downtown Oakland, and East Oakland on which every pair of destinations has a direct train, or else East Oakland residents would have to change trains to access their own city center – and current plans for a second trans-Bay tube add further reverse-branches instead of using the extra capacity as an opportunity to fix the Oakland junction.

Outside the United States, I know of four reverse-branches on rapid transit that is not historically regional rail: the Delhi Green Line, the Namboku and Mita Lines in Tokyo, the Yurakucho and Fukutoshin Lines also in Tokyo, and the Northern line’s two trunks in London. Of those, the last one is slowly being disentangled: its southern end will be two separate lines once the Battersea extension opens, and its northern end will, severing the line in two, once upgrades to pedestrian circulation are completed at the branch point. Historically Toronto had a three-way wye on the subway, like BART, but it caused so many problems it was discontinued in favor of running two separate lines.

Regional rail

The most prominent feature of American rail networks is not what they do, but what they lack. American (and Canadian, and Chinese) regional rail networks remain unmodernized, run for the exclusive benefit of upper middle-class suburban office workers at the primary CBD. Details differ between cities, but even when management is theoretically part of the same agency as the rapid transit network, as in Boston, New York, and Philadelphia, in practice the commuter railroads are autonomous. There is no hint of fare integration or schedule integration.

This fact influences network design more than anything else, even the low quality of steel els. Service to any destination beyond the dense urban core, which is small outside a handful of relatively dense cities, requires building new rail from scratch. This favors low-cost, low-capacity light rail, often in freeway medians. Smaller cities, unable to afford enough light rail to convince entire counties to tax themselves to build transit, downgrade service one step further and build bus rapid transit, typically treated as a weird hybrid of Latin American busways and European bus lanes.

Does any of this work?

In one word, no. The American tradition of rapid transit clearly doesn’t work – just look at the weak ridership even in old cities like Boston and Philadelphia, whose mode shares compare with medium-size urban regions in the French sunbelt like the Riviera or Toulouse.

Or, more precisely, it doesn’t work in early-21st century America. In the rare occasion an American city manages to round up funding to build a new subway line, I would recommend looking abroad for models of both construction methods and network design. For example, as BART keeps working on designing the second tube, I would strongly advise against new branches on the East Bay – instead, one of the two tubes (old and new) should permanently serve East Oakland, with a new Downtown Oakland transfer station, and the other should serve Berkeley and Concord.

Moreover, the United States owes it to itself to aggressively modernize its mainline passenger rail network. It’s too important to let Amtrak, the LIRR, Metro-North, Metra, and other dinosaurs do what they’ve always done. Toronto’s modernization of GO Transit, named the Toronto RER after the Western world’s premier regional rail network, had wide support among transit planners, but the engineers at GO itself were against it, and Metrolinx had to drag them into the 21st century.

Where the American tradition does work is in contexts that the United States has long left behind. Booming third-world cities direly need rapid transit, and while American construction costs are not to be emulated, the concept of opening up major throughfares, laying four tracks, and covering the system is sound. The mix of underground construction in city center and elevated construction farther out (using concrete structure, not louder steel ones) is sound as well, and is already seeing use in China and India. This is especially useful in cities that have little to no legacy regional rail, in which category India and China do not qualify, but most of the rest of the third world does.

Globalization makes for grand shuffles like this one. Experts in the United States should go to Nigeria, Bangladesh, Pakistan, Colombia, Kenya, Tanzania, Angola, and the Philippines and advise people in these countries’ major cities about how to emulate rapid transit designs from early-20th century America. But in their home country these same experts should instead step aside and let people with experience in the traditions of Japan, South Korea, and the various distinct countries of Western and Central Europe make decisions.

Meme Weeding: Los Angeles Density

If you’re the kind of total nerd that looks up tables on Wikipedia for fun, you may notice a peculiarity: the American built-up area with the highest population density is Los Angeles, followed by the Bay Area and New York. This is not what anyone experiences from even a slight familiarity with the two cities. Some people leave it at that and begin to make “well, actually Los Angeles is dense” arguments; this is especially common among supporters of cars and suburbs, like Randall O’Toole, perhaps because they advocate for positions the urbanist mainstream opposes and enjoy the ability to bring up an unintuitive fact. Others instead try to be more analytic about it and understand how Los Angeles’ higher headline density than New York coexists with its actual auto-centric form.

The answer that the urbanist Internet (blogs, then the Census Bureau, then Twitter) standardized on is that the built-up area of New York has some really low-density outer margins, where auto use is high, but the dense core is larger than that of Los Angeles. Here’s a log graph made by longtime Twitter follower Neil Patel:

New York’s 70th percentile of density (shown as 30 on the graph’s y-axis) is far denser than that of the comparison cities. The term the urbanist blogosphere defaulted to is “weighted density,” which is the average density of census tracts weighted by their population rather than area; see original post by the Austin Contrarian, in 2008.

But one problem remains: Los Angeles is by any metric still dense. Neil’s chart above shows its density curve Lorenz-dominating those of Chicago and Washington, both of which have far higher transit usage. Unfortunately, I haven’t seen too much analysis of why. Jarrett Walker talks about Los Angeles’s polycentrism, comparing it with Paris, and boosting it as a positive for public transit. The reality is the opposite, and it’s worth delving more into it to understand why whatever density Los Angeles has fails to make it have even rudimentary public transit.

Yes, Los Angeles is auto-oriented

The “well, actually Los Angeles is not autopia” line faces a sobering fact: Los Angeles has practically no transit ridership. In this section, I’m going to make some comparisons among American metropolitan statistical areas (MSAs); these exclude many suburbs, including the Inland Empire for Los Angeles and Silicon Valley for San Francisco, but Neil’s graph above excludes them as well, because of how the US defines urbanized areas. In the following table, income refers to median income among people driving alone or taking public transit, and all data is from the 2017 American Community Survey (ACS).

Place Workers Drive share Drive income Transit share Transit income
US 152,802,672 76.4% $38,689 5% $37,530
New York 9,821,147 50% $48,812 31% $44,978
San Francisco 2,371,803 57% $54,923 17.4% $62,500
Washington 3,320,895 66.4% $53,390 12.8% $60,420
Chicago 4,653,591 70% $41,817 12.2% $46,796
Los Angeles 6,434,177 75.4% $39,627 4.8% $21,153

The income numbers are not typos. In San Francisco, Washington, and Chicago, transit users outearn drivers. In New York the incomes are close, and US-wide they are almost even. But in Los Angeles, drivers outearn the few transit users almost 2:1. It’s not because Los Angeles has better transit in poor neighborhoods than in rich ones: this may have been true for a long while, but with the Expo Line open to Santa Monica, the Westside has bare bones coverage just like the rest of the city. Even with the coverage that exists, public transit in Los Angeles is so bad that people only use it if they are desperately poor.

When public transportation is a backstop service for the indigent, ridership doesn’t follow the same trends seen elsewhere. Transit ridership in Los Angeles rises and falls based on fares; new rail extensions, which have led to big gains in ridership in Seattle and Vancouver, are swamped by the impact of fare changes in Los Angeles. Gentrification, which in New York has steadily raised subway usage in hotspots like Williamsburg and which does the same in San Francisco, has instead (slightly) contributed to falling transit usage in Los Angeles (p. 53).

Job density and CBD job share

Los Angeles has high residential density by American standards – lower than in New York counted properly, but comparable to San Francisco, and higher than Chicago and Washington. However, job density tells a completely different story. New York, Chicago, San Francisco, and Washington all have prominent central business districts. Without a consistent definition of the CBD, I am drawing what look like the peak employment density sites from OnTheMap, all as of 2015:

Place CBD boundaries Area Jobs MSA share Density
New York 33rd, 3rd, 60th, 9th 3.85 825,476 8.4% 214,336
San Francisco Washington, Powell, 5th, Howard, Embarcadero 1.81 224,010 9.4% 123,558
Washington Rock Creek, P, Mass., 7th, Cons., 14th, H 3.26 240,505 7.2% 73,775
Chicago River, Congress, Michigan, Randolph, Columbus 1.61 368,910 7.9% 228,998
Los Angeles US 110, US 101, Alameda, 1st, Main, 7th 2.11 189,767 2.9% 89,937

The two main indicators to look for are the rightmost two columns: the percentage of jobs that are in the CBD, and the job density within the CBD. These indicators are highly not robust to changing the CBD’s definition, but expanding the definition moves them in opposite direction. Washington and San Francisco can be boosted to about 400,000 jobs each if the CBD is expanded to include near-CBD job centers such as Gallery Place, L’Enfant Plaza, SoMa, and Civic Center. Manhattan south of 60th has 1.9 million jobs in 22.2 km^2. Even in Chicago, where job density craters outside the Loop, the 9 km^2 bounded by Chicago, Halsted, and Roosevelt have 567,000 jobs. In making the tradeoff between job density and MSA share, I tried to use smaller CBD definitions, maximizing density at the expense of MSA share.

But even with this choice, the unusually low CBD share in Los Angeles is visible. This is what Jarrett and others mean when they say Los Angeles is polycentric: it is less dominated by its central business district than New York, Chicago, Washington, and San Francisco.

However, the comparisons between Los Angeles and Paris are wildly off-base. I am not including Paris in my above table, because INSEE only reports job numbers at the arrondissement level, and the city’s CBD straddles portions of the 1st, 2nd, 8th, and 9th arrondissements. Those four arrondissements total 405,189 jobs in 8.88 km^2, but in practice few of these jobs are in the outer quartiers, so a large majority of these jobs are in the central 4.64 km^2. The overall job density is then comparable to that of the Los Angeles CBD, but the similarity stops there: CBD employment is 7.1% of the total for Ile-de-France. If there is a US city that’s similar to Paris on the two CBD metrics of density and employment share, it’s Washington, not coincidentally the only big American city with a height-limited city center.

Secondary centers

In all of the American cities I’m comparing in this post except New York, the share of the population using public transit to get to work is not much higher than the share working in the CBD, especially if we add in near-CBD job centers served by public transit like Civic Center and L’Enfant Plaza (and all of the Manhattan core outside Midtown). This is not a coincidence. Outside a few distinguished locations with high job density, it’s easy enough to drive, and hard to take the train (if it even exists) except from one or two directions.

American cities are distinguished from European ones in that their non-CBD employment is likely to be in sprawling office parks and not in dense secondary centers. Paris is polycentric in the sense of having multiple actual centers: La Defense is the most conspicuous outside the CBD, but the city is full of smaller, lower-rise clusters: the Latin Quarter, Bercy, the Asian Quarter, Gare du Nord, the Marais. The 3rd, 4th, 5th, 6th, 7th, 10th, and 12th all have around 20,000-25,000 jobs per square kilometer, not much less than the Upper East Side (which has about 120,000 jobs between 60th and 96th Streets).

A polycentric city needs to have multiple actual centers. Does Los Angeles have such centers? Not really. Century City has 33,000 jobs in about 1.1 km^2. Here is the city’s second downtown, with a job density that only matches that of central Parisian neighborhoods that nobody would mistake with the CBD. The UCLA campus has around 15,000 jobs. Downtown Santa Monica has 24,000 in 2 km^2. El Segundo, which Let’s Go LA plugs as a good site for CBD formation, has 52,000 jobs in 5.2 km^2. Downtown Burbank has about 13,000 in 0.6 km^2. The dropoff in commercial development intensity from the primary CBD is steep in Los Angeles.

What Los Angeles has is not polycentric development. Paris is polycentric. New York is fairly polycentric, with the growth of near-CBD clusters like Long Island City, in addition to older ones like Downtown Brooklyn and Downtown Newark. Los Angeles is just weak-centered.

The structure of density

In his original posts about weighted density from 2008, Chris noted not just the overall weighted density of an American urban area but also the ratio of the weighted to standard density. This ratio is highest in New York, but after New York the highest ratios are in other old industrial cities like Boston and Chicago. This ratio is in stronger correlation with the public transit modal share than weighted density. Much of this fact is driven by the fact that Boston, Chicago, and Philadelphia have high-for-America transit usage and Los Angeles doesn’t, but it still suggests that there is something there regarding the structure of density.

In Chicago and Washington, the population density is low, but it follows a certain structure, with higher density in central areas and in distinguished zones near train stations. These structures are not identical. Chicago has fairly uniform density within each city neighborhood, and only sees this structure in the suburbs, which are oriented around commuter rail stations, where people take Metra to the city at rush hour (and drive for all other purposes). In contrast, in Washington commuter rail is barely a footnote, whereas Metro drives transit-oriented development in clusters like Arlington, Alexandria, Silver Spring, and Bethesda. In these islands of density, the transit-oriented lifestyle is at least semi-plausible.

Paris has fairly uniform density within the city, but it has strong TOD structure in the suburbs: high density within walking distance of RER stations, lower density elsewhere. Some RER stations are also surrounded by job clusters oriented toward the train station: La Defense is by far the biggest and best-known, but Cergy, Val d’Europe and Marne la Vallee, Issy, Noisy, and Saint-Denis are all walkable to job centers and not just housing. Within the city there is no obvious structure, but the density is so high and the Metro so ubiquitous that transit serves the secondary nodes well.

In Los Angeles, there is no structure to density. There are some missing middle and mid-rise neighborhoods, but few form contiguous blobs of high density that can be served by a rapid transit line. Koreatown is in a near-tie with Little Osaka for highest population density in the United States outside New York, but immediately to its west, on the Purple Line Extension, lie kilometers of single-family sprawl, and only farther west on Wilshire can one see any density (in contrast, behind Little Osaka on Geary lies continuous density all the way to the Richmond). With the exception of Century City, UCLA, and Santa Monica, the secondary centers don’t lie on any obvious existing or current transit line.

With no coherent structure, Los Angeles is stuck. Its dense areas are too far away from one another and from job centers to be a plausible urban zone where driving is not necessary for a respectable middle-class lifestyle. Buses are far too slow, and trains don’t exist except in a handful of neighborhoods. Worse, because the density is so haphazard, the rail extensions can’t get any ridership. The ridership projection for the Purple Line Extension is an embarrassing 78,000 per weekday for nearly 15 km and $8.2 billion. The construction cost is bad, but in a large, dense city should be offset by high ridership (as it is in London); but it isn’t, so the projected ridership per kilometer is on a par with some New York City Transit buses and the projected cost per rider is so high that it is usually reserved for airport connectors.

The way out

In a smaller, cheaper auto-centric city, like Nashville or Orlando, I would be entirely pessimistic. In Los Angeles there is exactly one way out: fix the urban design, and reinforce it with a strong rail network.

The fact that this solution exists does not mean it is politically easy. In particular, the region needs to get over two hangups, each of which is separately nearly insurmountable. The first is NIMBYism. Los Angeles is so expensive that if it abolishes its zoning code, or passes a TOD ordinance that comes close to it, it could see explosive growth in population, which would be concentrated on the Westside, creating a large zone of high density in which people could ride the trains. However, the Westside is rich and very NIMBY. Metro isn’t even trying to upzone there: the Purple Line Extension has a 3.2-km nonstop segment from Western to La Brea, since the single-family houses in between are too hard to replace with density. Redeveloping the golf courses that hem Century City so that it could grow to a real second downtown is attractive as well, but even the YIMBYs think it’s unrealistic.

The second obstacle is the hesitation about spending large amounts of money all at once. American politicians are risk-averse and treat all spending as risk, and this is true even of politicians who boldly proclaim themselves forward-thinking and progressive. Even when large amounts of money are at stake, their instincts are to spread them across so many competing goals that nothing gets funded properly. The amount of money Los Angeles voters have approved to spend on transportation would build many rapid transit lines, even without big decreases in construction costs, but instead the money is wasted on showcasing bus lanes (this is Metro’s official blog’s excuse for putting bus lanes on Vermont and not rapid transit) or fixing roads or the black hole of Metro operating costs.

But the fact that Los Angeles could be a transit city with drastic changes to its outlook on development and transportation investment priorities does not mean that it is a transit city now. Nor does it mean that the ongoing program of wasting money on low-ridership subway lines is likely to increase transit usage by the required amount. Los Angeles does not have public transportation today in the sense that the term is understood here or in New York or even in Chicago. It should consider itself lucky that it can have transit in the future if it implements politically painful changes, but until it does, it will remain the autopia everyone outside urbanism thinks it is.

Sometimes, Bus Stop Consolidation is Inappropriate

For the most part, the optimal average spacing between bus stops is 400-500 meters. North American transit agencies have standardized on a bus stop every 200-250 meters, so stop consolidation is usually a very good idea. But this is based on a model with specific inputs regarding travel behavior. In some circumstances, travel behavior is different, leading to different inputs, and then the model’s output will suggest a different optimum. In contrast with my and Eric’s proposal for harsh stop consolidation in Brooklyn, I would not recommend stop consolidation on the crosstown buses in Manhattan, and am skeptical of the utility of stop consolidation in Paris. In Vancouver I would recommend stop consolidation, but not on every route, not do we recommend equally sweeping changes on every single Brooklyn route.

The model for the optimal stop spacing

If demand along a line is isotropic, and the benefits of running buses more frequently due to higher in-vehicle speed are negligible, then the following formula holds:

\mbox{Optimum spacing} = \sqrt{2\cdot\frac{\mbox{walk speed}}{\mbox{walk penalty}}\cdot\mbox{stop penalty}\cdot\mbox{average trip distance}}

The most important complicating assumption is that if demand is not isotropic, but instead every trip begins or ends at a distinguished location where there is certainly a stop, such as a subway connection, then the formula changes to,

\mbox{Optimum spacing} = \sqrt{4\cdot\frac{\mbox{walk speed}}{\mbox{walk penalty}}\cdot\mbox{stop penalty}\cdot\mbox{average trip distance}}

The choice of which factor to use, 2 or 4, is not exogenous to the bus network. If the network encourages transferring, then connection points will become more prominent, making the higher factor more appropriate. Whether the network encourages interchanges depends on separate policies such as fare integration but also on the shape of the network, including bus frequency. Higher average bus speed permits higher frequency, which makes transferring easier. The model does not take the granularity of transfer ease into account, which would require a factor somewhere between 2 and 4 (and, really, additional factors for the impact of higher bus speed on frequency).

After the choice of factor, the most contentious variable is the walk speed and penalty. Models vary on both, and often they vary in directions that reinforce each other rather than canceling out (for example, certain disabilities reduce both walk speed and willingness to walk a minute longer to save a minute on a bus). In Carlos Daganzo’s textbook, the walk speed net of penalty is 1 m/s. For an able-bodied adult, the walk speed can exceed 1.5 m/s; penalties in models range from 1.75 (MTA) to 2 (a Dutch study) to 2.25 (MBTA). The lower end is probably more appropriate, since the penalty includes a wait penalty, and stop consolidation reduces waits even as it lengthens walk time.

Update 10/31: alert reader Colin Parker notes on social media that you can shoehorn the impact of walk time into the model relatively easily. The formula remains the same with one modification: the average trip distance is replaced with

\mbox{average trip distance} + \frac{\mbox{average distance between buses}\cdot\mbox{wait penalty}}{2}.

The factor of 2 in the formula comes from computing average wait time; for worst-case wait time, remove the 2 (but then the wait penalty would need to be adjusted, since the wait penalty is partly an uncertainty penalty).

The average distance between buses is proportional to the number of service-hours, or fleet size: it obeys the formula

\mbox{revenue service-hours per hour} = \frac{2\cdot\mbox{route-length}}{\mbox{average distance between buses}}.

The factor of 2 in the formula comes from the fact that route-length is measured one-way whereas revenue hours are for a roundtrip.

If we incorporate wait time into the model this way, then the walk and wait penalties used should be higher, since we’re taking them into account; the Dutch study’s factor of 2 is more reasonable. The conclusions below are not really changed – the optima barely increase, and are unchanged even in the cases where stop consolidation is not recommended.

The situation in New York

The average unlinked New York City Transit bus trip is 3.35 km: compare passenger-miles and passenger trips as of 2016. In theory this number is endogenous to the transit network – longer interstations encourage passengers to take the bus more for long trips than for short trips – but in practice the SBS routes, denoted as bus rapid transit in the link, actually have slightly shorter average trip length than the rest. For all intents and purposes, this figure can be regarded as exogenous to stop spacing.

The stop penalty, judging by the difference between local and limited routes, is different for different routes. The range among the routes I have checked looks like 20-40 seconds. However, Eric tells me that in practice the B41, which on paper has a fairly large stop penalty, has little difference in trip times between the local and limited versions. The local-SBS schedule difference is consistent with a stop penalty of about 25 seconds, at least on the B44 and B46.

As a sanity check, in Vancouver the scheduled stop penalty on 4th Avenue is 22 seconds – the 84 makes 19 fewer stops than the 4 between Burrard and UBC and is 7 minutes faster – and the buses generally run on schedule. The actual penalty is a little higher, since the 4 has a lot of pro forma stops on the University Endowment Lands that almost never get any riders (and thus the bus doesn’t stop there). This is consistent with 25 seconds at a stop that the bus actually makes, or even a little more.

Plugging the numbers into the formula yields

\mbox{Optimum spacing} = \sqrt{4\cdot\frac{1.5}{1.75}\cdot 25\cdot 3350} = 536 \mbox{ meters}

if we assume everyone connects to the subway (or otherwise takes the bus to a distinguished stop), or

\mbox{Optimum spacing} = \sqrt{2\cdot\frac{1.5}{1.75}\cdot 25\cdot 3350} = 379 \mbox{ meters}

if we assume perfectly isotropic travel demand. In reality, a large share of bus riders are connecting to the subway, which can be seen in fare revenue, just $1.16 per unlinked bus trip compared with $1.91 per subway trip (linked or unlinked, only one swipe is needed). In Brooklyn, it appears that passengers not connecting to the subway disproportionately go to specific distinguished destinations, such as the hospitals, universities, and shopping centers, or Downtown Brooklyn, making the higher figure more justified. Thus, our proposed stop spacing, excluding the long nonstop segments across the Brooklyn-Battery Tunnel and between borough line and JFK, is 490 meters.

Update 10/31: if we incorporate wait time, then we need to figure out the average distance between buses. This, in turn, depends on network shape. Brooklyn today has 550 km of bus route in each direction, which we propose to cut to 350. With around 600 service hours per hour – more at the peak, less off-peak – we get an average distance between buses of 1,830 meters today or 1,180 under our proposal. Using our proposed network, and a wait and walk penalty of 2, we get

\mbox{Optimum spacing} = \sqrt{4\cdot\frac{1.5}{2}\cdot 25\cdot (3350 + \frac{2\cdot 1180}{2}} = 583 \mbox{ meters}

or

\mbox{Optimum spacing} = \sqrt{2\cdot\frac{1.5}{2}\cdot 25\cdot (3350 + \frac{2\cdot 1180}{2})} = 412 \mbox{ meters}.

Short bus routes imply short stop spacing

Our analysis recommending 490 meter interstations in Brooklyn depends on the average features of New York’s bus network. The same analysis ports to most of the city. But in Manhattan, the situation is different in a key way: the crosstown buses are so short that the average trip length cannot possibly match city average.

Manhattan is not much wider than 3 km. Between First and West End Avenues the distance is 2.8 km. The likely average trip length is more than half the maximum, since the typical use case for the crosstown buses is travel between the Upper East Side and Upper West Side, but the dominant destinations are not at the ends of the line, but close to the middle. With Second Avenue Subway offering an attractive two-seat ride, there is less reason to take the crosstown buses to connect to the 1/2/3 (and indeed, the opening of the new line led to prominent drops in ridership on the M66, M72, M79, M86, and M96); the best subway connection point is now at Lexington Avenue, followed by Central Park West. On a long route, the location of the dominant stop is not too relevant, but on a short one, the average trip length is bounded by the distance between the dominant stop and the end of the line.

If we take the average trip length to be 1.6 km and plug it into the formula, we get

\mbox{Optimum spacing} = \sqrt{4\cdot\frac{1.5}{1.75}\cdot 25\cdot 1600} = 370 \mbox{ meters}

or

\mbox{Optimum spacing} = \sqrt{2\cdot\frac{1.5}{1.75}\cdot 25\cdot 1600} = 262 \mbox{ meters.}

A crosstown bus stopping at First, Second, Third, Lex, Madison, Fifth, Central Park West, Columbus, Amsterdam, Broadway, and West End makes 10 stops in 2.8 km, for an average of 280 meters. There isn’t much room for stop consolidation. If the bus continues to Riverside, lengthening the trip to 3 km at the latitude of 96th Street, then it’s possible to drop West End. If the buses running up Third and down Lex are converted to two-way running, presumably on Lex for the subway connections, then Third could be dropped, but this would still leave the interstation at 330 meters, much tighter than anything we’re proposing in Brooklyn.

The only other places where avenues are too closely spaced are poor locations for stop removal. Amsterdam and Broadway are very close, but Amsterdam carries a northbound bus, and if the Columbus/Amsterdam one-way pair is turned into two two-way avenues, then Amsterdam is a better location for the bus than Columbus because it provides better service to the Far West Side. Fifth and Madison are very close as well, but the buses using them, the M1 through M4, are so busy (a total of 32 buses per hour at the peak) that if the two avenues are converted to two-way running then both should host frequent bus trunks. It’s not possible to skip either.

Within Brooklyn, there is one location in which the same issue of short bus routes applies: Coney Island. The B74 and B36 act as short-hop connectors from Coney Island the neighborhood to Coney Island the subway station. The routes we propose replacing them have 7 stops each from the subway connection west, over distances of 2.5 and 2.7 km respectively, for interstations of 360 and 390 meters.

Vancouver supplies two more examples of routes similar to the B74 and B36: the 5 and 6 buses, both connecting the West End with Downtown. The 6 is only 2 km between its western end and the Yaletown SkyTrain station, and the 5 is 2.3 km from the end to the Burrard station and 2.8 km to city center at Granville Street. The average trip length on these buses is necessarily short, which means that stop consolidation is not beneficial, unlike on the main grid routes outside Downtown.

Update 10/31: incorporating wait time into this calculation leads to the same general conclusion. The short routes in question – the Manhattan crosstowns, the B36 and B74, and the 5 and 6 in Vancouver – have high frequency, or in other words short distance between buses. For example, the M96 runs every 4 minutes peak, 6 off-peak, and takes 22-24 minutes one-way, for a total of 6 circulating buses per direction peak (which is 500 meters), or 4 off-peak (which is 750 meters). This yields

\mbox{Optimum spacing} = \sqrt{2\cdot\frac{1.5}{2}\cdot 25\cdot (1600 + \frac{2\cdot 500}{2})} = 281 \mbox{ meters.}

A network that discourages transferring should have more stops as well

In Paris the average interstation on buses in the city looks like 300 meters; this is not based on a citywide average but on looking at the few buses for which Wikipedia has data plus a few trunks on the map, which range from 250 to 370 meters between stations.

The short stop spacing in Paris is justified. First of all, the average bus trip in Paris is short: 2.33 km as of 2009 (source, PDF-p. 24). Parisian Metro coverage is so complete that the buses are not useful for long trips – Metro station access time is short enough that the trains overtake the buses on total trip time very quickly.

Second, there is little reason to transfer between buses here, or to transfer between buses and the Metro. The completeness of Metro coverage is such that buses are just not competitive unless they offer a one-seat ride where the Metro doesn’t. Another advantage of buses is that they are wheelchair-accessible, whereas the Metro is the single least accessible major urban rail network in the world, with nothing accessible to wheelchair users except Line 14 and the RER A and B. It goes without saying that people in wheelchairs are not transferring between the bus and the Metro (and even if they could, they’d have hefty transfer penalties). The New York City Subway has poor accessibility, but nearly all of the major stations are accessible, including the main bus transfer points, such as Brooklyn College and the Utica Avenue stop on the 3/4.

With little interchange and a mostly isotropic city density, the correct formula for the optimal bus stop spacing within Paris is

\mbox{Optimum spacing} = \sqrt{2\cdot\frac{1.5}{1.75}\cdot 25\cdot 2330} = 316 \mbox{ meters,}

which is close to the midpoint of the range of interstations I have found looking at various routes.

Conclusion

The half-kilometer (or quarter-to-a-third-of-a-mile) rule for bus stop spacing is an empirical guideline. It is meant to describe average behavior in the average city. It is scale-invariant – the density of the city does not matter, only relative density does, and the size of the city only matters insofar as it may affect the average trip length. However, while scale itself does not lead to major changes from the guideline, special circumstances might.

If the geography of the city is such that bus trips are very short, then it’s correct to have closer stop spacing. This is the case for east-west travel in Manhattan. It is also common on buses that offer short-hop connections to the subway from a neighborhood just outside walking range, such as the B36 and B74 in Coney Island and the 5 and 6 in Vancouver’s West End.

Note that even in New York, with its 3.3 km average trip length, stop consolidation is still beneficial and necessary on most routes. North American transit agencies should not use this article as an excuse not to remove extraneous stops. But nor should they stick to a rigid stop spacing come what may; on some routes, encouraging very short trips (often 1.5 km or even less), closely spaced stations are correct, since passengers wouldn’t be riding for long enough for the gains from stop consolidation to accumulate.

How Transit and Green Tech Make Economic Geography More Local

The theme of winners and losers has been on my mind for the last few months, due to the politics of the Brooklyn bus redesign. In a rich country, practically every social or political decisions is win-lose, even if the winners greatly outnumber the losers. It’s possible to guarantee a soft landing to some of the losers, but sometime even the soft landing is disruptive, and it’s crucial that backers of social change be honest with themselves and with the public about this. Overall, a shift from an auto-oriented society to a transit-oriented one and from dirty energy to clean energy is positive and must be pursued everywhere, but it does have downsides. In short, it changes economic geography in ways that make certain regions (like Detroit or the Gulf Cooperation Council states) redundant; it reorients economies toward more local consumption, so oil, gas, and heavy industry jobs would not be replaced with similar manufacturing or mining clusters but with slightly more work everywhere else in the world.

Dirty production is exportable

The United States has the dirtiest economy among the large developed countries, so it’s convenient to look at average American behavior to see where the money that is spent on polluting products goes.

Nationally, about 15.9% of consumer spending is on transportation. The vast majority of that is on cars, 93.1% (that is, 14.7% of total consumer spending). The actual purchase of the car is 42% of transportation spending, or 6.7% of household spending. This goes to an industry that, while including local dealerships (for both new and used cars), mostly consists of auto plants, making cars in suburban Detroit or in low-wage Southern states and exporting them nationwide.

In addition to this 6% of consumer spending on cars, there’s fuel. Around 3% of American household spending is on fuel for cars. Overall US oil consumption in 2017 was 7.28 billion barrels, which at $52/barrel is 5% of household spending; the difference between 5 and 3 consists of oil consumed not by households. This is a total of about 2% of American GDP, which includes, in addition to household spending, capital goods and government purchases. This tranche of the American economy, too, is not local, but rather goes to the oil industry domestically (such as to Texas or Alaska) or internationally (such as to Alberta or Saudi Arabia).

Historically, when coal was more economically significant, it was exportable too. Money flowed from consumers, such as in New York and London, to producers in the Lackawanna Valley or Northeast England; today, it still flows to remaining mines, such as in Wyoming.

The same is true of much of the supply chain for carbon-intensive products. Heavy industry in general has very high carbon content for its economic value, which explains how the Soviet Union had high greenhouse gas emissions even with low car usage (15.7 metric tons per capita in the late 1980s) – it had heavy industry just as the capital bloc did, but lagged in relatively low-carbon consumer goods and services. The economic geography of steel, cement, and other dirty products is again concentrated in industrial areas. In the US, Pittsburgh is famous for its historical steel production, and in general heavy manufacturing clusters in the Midwestern parts of the Rust Belt and in transplants in specific Southern sites.

All of these production zones support local economies. The top executives may well live elsewhere – for example, David Koch lives in New York and Charles Koch in Wichita (whose economy is based on airplane manufacturing and agriculture, neither of which the Kochs are involved in). But the working managers live in city regions dedicated to servicing the industry, the way office workers in the oil industry tend to live in Houston or Calgary, and of course the line workers live near the plants and mines.

Clean alternatives are more local

The direct alternatives to oil, gas, and cars are renewable energy and public transportation. These, too, have some components that can be made centrally and exported, such as solar panel and rolling stock manufacturing. However, these components are a small fraction of total spending.

How small? Let’s look at New York City Transit. Its operating costs are about $9.1 billion a year as of 2016, counting both the subway and buses. Nearly all of this is wages, salaries, and benefits: $7.3 billion, compared with only $500 million for materials and supplies. This specifically excludes vehicle purchases, which in American transit accounting are lumped as capital costs. The total NYCT fleet is about 6,400 subway cars, which cost around $2.3 million each and last 40+ years, and 5,700 buses, which cost around $500,000 each and last 12 years, for a total depreciation charge of around $600 million a year combined.

Compare this with cars: New York has about 2 million registered cars, but at the same average car ownership rate as the rest of the US, 845 per 1,000 people, it would have 7.3 million cars. These 5.3 million extra cars would cost $36,500 each today, and last around 20 years, for a total annual depreciation charge of $9.7 billion.

Put another way, total spending on vehicles at NYCT is one sixteenth what it would take to raise the city’s car ownership rate to match the national average. Even lumping in materials and supplies that are not equipment, such as spare parts and fuel for buses, the total, $1.1 billion, is one ninth as high as buying New Yorkers cars so that they can behave like Americans outside the city, and that’s without counting the cost of fuel. In particular, there is no hope of maintaining auto plant employment by retraining auto workers to make trains, as Michael Moore proposed in 2009.

The vast majority of transit spending is then local: bus and train operations, maintenance, and local management. The same is true of capital spending, which goes to local workers, contractors, and consultants, and even when it is outsourced to international firms, the bulk of the value of the contract does not accrue to Dragados or Parsons Brinckerhoff.

Clean energy is similarly local. Solar panels can be manufactured centrally, but installing them on rooftops is done locally. Moreover, the elimination of carbon emissions coming from buildings has to come not just from cleaner electricity but also from reducing electricity consumption through passive solar construction. Retrofitting houses to be more energy-efficient is a labor-intensive task comprising local builders sealing gaps in the walls, windows, and ceilings.

Low-carbon economic production can be exported, but not necessarily from Detroit

A global shift away from greenhouse gas emissions does not mean just replacing cars and oil with transit and solar power. Transit is cheaper to operate than cars: in metro New York, 80.5% of personal transportation expenditure is still on cars, and the rest is (as in the rest of the country) partly on air travel and not transit fare, whereas work trip mode shares in the metropolitan statistical area are 56% car, 31% transit. With its relatively high (for North America) transit usage, metro New York has the lowest share of household spending going to transportation, just 11.4%. This missing consumption goes elsewhere. Where does it go?

The answer is low-carbon industries. Consuming less oil, steel, and concrete means not just consuming more local labor for making buildings more efficient and running public transit, but also shifting consumption to less carbon-intensive industries. This low-carbon consumption includes local purchases, for example going out to eat, or hiring a babysitter to look after the kids, neither of which involves any carbon emissions. But it also includes some goods that can be made centrally. What are they, and can they be made in the same areas that make cars and steel or drill for oil and gas?

The answer is no. First, in supply regions like the Athabascan Basin, Dammam, and the North Slope of Alaksa, there’s no real infrastructure for any economic production other than oil production. The infrastructure (in the case of North America) and the institutions (in the case of the Persian Gulf) are not suited for any kind of manufacturing. Second, in real cities geared around a single industry, like Detroit or Houston, there are still lingering problems with workforce quality, business culture, infrastructure, and other necessities for economic diversification.

Take the tech industry as an example. The industry itself is very low-carbon, in the sense that software is practically zero-carbon and even hardware has low carbon content relative to its market value. Some individual tech products are dirty, such as Uber, but the industry overall is clean. A high carbon tax is likely to lead to a consumption shift toward tech. And tech as an industry has little to look for in Detroit and Houston. Austin has booming tech employment, but Houston does not, despite having an extensive engineering sector courtesy of the oil industry as well as NASA. The business culture in the space industry (which is wedded to military contracting) is alien to that of tech and vice versa; the way workers are interviewed, hired, and promoted is completely different. I doubt the engineers oil and auto industries are any more amenable to career change to software.

On the level of line workers rather than engineers, the situation is even worse. A manufacturing worker in heavy industry can retrain to work in light industry, or in a non-exportable industry like construction, but light industry has little need for the massive factories that churn out cars and steel. And non-manufacturing exports like tech don’t employ armies of manufacturing workers.

In Germany the situation is better, in that Munich and Stuttgart may have little software, but they do have less dirty manufacturing in addition to their auto industries. It’s likely that if global demand for cars shifts to a global demand for trains then Munich will likely keep thriving – it’s the home of not just BMW and Man but also Siemens. However, the institutions and worker training that have turned southern Germany into an economically diverse powerhouse have not really replicated outside Germany. Ultimately, in a decarbonizing world, southern Germany will be the winner among many heavy industrial regions, most of which won’t do so well.

There’s no alternative to shrinkage in some cities

A shift away from fossil fuel and cars toward green energy and public transit does not have to be harsh. It can aim to give individual workers in those industries a relatively soft landing. However, two snags remain, and are unavoidable.

The first is that some line workers have deliberately chosen poor working conditions in exchange for high wages; the linked example is about oil rig workers in Alaska, but the same issue occurs in some unionized manufacturing and services, for example electricians get high wages but all suffer hearing loss by their 50s. It’s possible to retrain workers and find them work that’s at the same place on the average person’s indifference curve between pay and work conditions, but since those workers evidently chose higher-pay, more dangerous jobs, their personal preference is likely to weight money more than work conditions and thus they’re likely to be unhappy with any alternative.

The second and more important snag is the effect of retraining on entire regions. Areas that specialize to oil, gas, cars, and to some extent other heavy industry today are going to suffer economic decline, as the rest of the world shifts its consumption to either local goods (such as transit operations) or different economic sectors that have no reason to locate in these areas (such as software).

Nobody will be sad to see Saudi Arabia crash except people who are directly paid by its government. But the leaders of Texas and Michigan are not Mohammad bin Salman; nonetheless, it is necessary to proceed with decarbonization. It’s not really possible to guarantee the communities a soft landing. Governments all over the world have wasted vast amounts of money trying and failing to diversify from one sector (e.g. oil in the GCC states) or attract an industry in vogue (e.g. tech anywhere in the world). If engineering in Detroit and Houston can’t diversify on its own, there’s nothing the government can do to improve it, and thus these city regions are destined to become much smaller than they are today.

This is bound to have knock-on regional effects. Entire regions don’t die quietly. Firms specializing in professional services to the relevant industries (such as Halliburton) will have to retool. Small business owners who’ve dedicated their lives to selling food or insurance or hardware to Houstonians and suburban Detroit white flighters will need to leave, just as their counterparts in now-dead mining towns or in Detroit proper did. Some will succeed elsewhere, just as many people in New Orleans who were displaced by Katrina found success in Houston. But not all will. And it’s not possible to guarantee all of them a soft landing, because it’s not possible to guarantee that every new small business will succeed.

All policy, even very good policy, has human costs. There are ways to reduce these costs, through worker retraining and expansion of alternative employment (such as retrofitting older houses to be more energy-efficient). But there is no way to eliminate these costs. Some people who are comfortable today will be made precarious by any serious decarbonization program; put another way, these people’s entire livelihood depends on continuing to destroy the planet, and most of them are not executives at oil and gas companies. It does not mean that decarbonization should be abandoned or even that it should be pursued more hesitantly; but it does mean climate activists, including transit activists, have to be honest about how it affects people in and around polluting industries.

Quick Note: What We Can Learn from Russian Construction Costs

There is relatively scant information in English about construction costs in Russia and China. Frustratingly, even Metro Report, which does have some information about China, has only a handful of Russian examples with their costs stated; from perusing the articles Wikipedia links to, even Russian originals rarely state the costs of subway extensions.

Fortunately, Metro Report does have an article mentioning general costs. Be warned: the costs quoted below are somewhat higher than the specific figures I’ve found for individual projects.

Tunnels, including stations and depots, cost an average of 10bn to 15bn roubles per route-km to build, with construction of an extension lasting five to six years. Cut-and-cover methods can save 2bn to 5bn roubles and up to three to four years. Additional savings could be made by using double-track bored tunnels, which first appeared in 2014-15 in St Petersburg, along with top-down station construction. At some stations in Moscow, platform arrangements are being introduced with a platform on each side of a single track so that boarding and alighting passengers do not use the same platform; this leads to a 15% to 30% saving on the overall construction cost.

The PPP conversion rate is about US$1 = 24 rubles as of 2016-7. So the overall cost quoted is supposedly around $400-600 million per km, which is very high for a European country, and overlaps the American range (though the $500 million/km American subways tend not to be in city centers). In practice, the two specific lines cited in the article are cheaper, at $310 million/km for the Line 3 extension in Saint Petersburg (which is partly underwater) and $185 million/km for the Line 2 extension in Nizhny Novgorod; but both extensions have wide stop spacing even by Russian standards, and deep underground, stations dominate construction costs.

Look more carefully at the quoted paragraph. Using side platforms rather than island platforms is stated to reduce costs by 15-30% – presumably overall costs, not just station costs. This is because the caverns are simpler, especially if the stations are built cut-and-cover. Cut-and-cover overall is supposed to save 20-30% of the cost, taking the 10-15 billion figure as correct and not the lower figures of the Saint Petersburg and Nizhny Novgorod lines mentioned in the piece. If the lower figures are right, the saving is around half the cost, making cut-and-cover cost about the same as above-ground construction (an above-ground Line 1 extension is projected to cost $130 million/km).

I saw a different source, in French, make the same claim that cut-and-cover is about as expensive as elevated construction; I can’t find the reference anymore, but interested readers can Google “ciel couvert” and see if they can find the article. This was very much not the case in 1900-4, when New York was spending (in today’s money) around $39 million/km on the subway’s underground portions and $9 million/km on its elevated portions, but then again New York built els to be cheap and noisy, and it’s plausible that quieter concrete structures would cost more.

Another plausible explanation is that cut-and-cover has gotten relatively cheaper over time due to mechanization of street digging. New York and Paris built their subways with hand tools in the 1900s. Deep boring is more mechanized, but was already somewhat mechanized at the turn of the century, so it’s not surprising if the cost trajectory in the last 120 years has been more favorable to cut-and-cover. As it is, London’s early Tube lines didn’t cost more than the cut-and-cover lines of New York or Paris, nor did they cost more in the 1930s; the cost differential is thus a recent phenomenon.

Finally, on a more political point, it’s worth comparing Russia with other countries that used to be in the Soviet bloc, since they have broadly comparable incomes today and learned to build subways from the same place (i.e. the Moscow Metro and the Soviet triangle). Overall, Russian costs seem somewhat higher than in the rest of Eastern Europe: comparable to costs in Poland or a little higher, somewhat lower than Hungary (M4 was around $500 million/km), much higher than Bulgaria and Romania. Does EU membership and the package of reforms required for accession mean lower construction costs? It’s not guaranteed, but it looks like the parts of former communist Europe that joined the EU are doing better. Upper middle-income wages with good institutions can produce good results, just as the never-communist parts of Europe with comparable incomes, like Greece and Italy, have pretty low costs.

How to Design Rail Service to Connect to Buses Better

Usually, integrated transit planning means designing bus networks to feed rail trunks better. Buses are mobile: their routes can move based on long-term changes in the city’s physical and economic layout. Railroads in contrast have high installation costs. Between the relative ease of moving buses and the fact that there’s a hierarchy in which trains are more central than buses, buses normally should be feeding the trains. However, there are some cases in which the opposite happens: that is, cases in which it’s valuable to design rail infrastructure based on expected bus corridors. Moreover, in developed and middle-income countries these situations are getting more rather than less frequent, due to the increasing use of deep tunneling and large station complexes.

In nearly every circumstance, the hierarchy of bus and rail remains as it is; the exceptions (like Ottawa, at least until the light rail subway opens) are so rare as to be notable. What I posit is that in some situations, rail infrastructure should be designed better to allow buses to feed the trains more efficiently. This mostly affects station infrastructure, but there are also reasons to choose routes based on bus feeding.

Major bus corridors

Surface transit likes following major streets. Years ago, I blogged about this here and here. Major streets have two relevant features: they are wide, permitting buses (or streetcars) to run in generous dedicated lanes without having to deal with too much traffic; and they have continuous linear development, suitable for frequent bus stops (about every half kilometer).

These two features are likely to remain important for surface transit for the foreseeable future. The guidelines for good surface transit service depend on empirical parameters like the transfer penalty (in particular, grids are not the universal optimum for bus networks), but major corridors are relatively insensitive to them. The walk penalty can change the optimal bus stop spacing, but not in a way that changes the basic picture of corridor-based planning. Which streets have the most development is subject to change as city economic and social geography evolves, but which streets are the widest doesn’t. What’s more, a train station at a street intersection is likely to cement the cross-street’s value, making adverse future change less likely.

Note that we don’t have to be certain which major streets will host the most important buses in the future. We just need to know that major buses will follow major streets.

The conclusion is that good locations for rail infrastructure are major intersecting streets. On a commuter line, this means stations should ideally be placed at intersections with roads that can carry connecting buses. On a subway line, this means the same at a more local scale.

Stations and accessibility

When possible, train stations should locate at intersections with through-streets, to permit efficient transfers. This also carries over to station exits, an important consideration given the complexity of many recently-built stations in major rich and middle-income cities.

It goes without saying that a Manhattan subway line should have stations with exits at 72nd, 79th, 86th, 96th, etc. streets. Here, Second Avenue Subway does better than the Lexington Avenue Line, whose stations are chosen based on a 9-block stop spacing and miss the intersecting buses.

However, it’s equally important to make sure that the accessible exits are located at major streets as well. One bad example in New York is the Prospect Park B/Q station: it has two exits, one inaccessible on Flatbush Avenue and one accessible on Empire Boulevard. In theory both are major corridors, but Flatbush is far and away the more important ones, one of the busiest surface transit corridors in the city, while Empire competes for east-west buses with Kings County Hospital, the borough’s biggest job center outside Downtown Brooklyn. Eric Goldwyn’s and my Brooklyn bus redesign breaks the B41 bus on Flatbush and loops it and the Washington Avenue routes around the station complex to reach the accessible exit.

The Prospect Park case is one example of an almost-right decision. The full-time, accessible exit is close to Flatbush, but not quite there. Another example is Fields Corner: the eastern end of the platform is 80 meters from Dorchester Avenue, a major throughfare, and 180 meters from Adams Avenue, another major street, which unlike Dot Ave diverges from the direction the Red Line takes on its way south and is a useful feeder bus route.

Commuter rail and feeder buses

The station placement problem appears especially acute on mainline rail. This is not just an American problem: suburban RER stations are built without regard for major crossing roads (see, for example, the RER B airport branch and the RER A Marne-la-Vallee branch, both built in the 1970s). Railroads historically didn’t think much in terms of systemwide integration, but even when they were turned into modern rapid transit, questionable stop locations persisted; the Ashmont branch of the Red Line in Boston was taken over from mainline rail in the 1920s, but Fields Corner was not realigned to have exits at Dot and Adams.

Today, the importance of feeder buses is better-understood, at least by competent metropolitan transportation planners. This means that some stations need to be realigned, and in some places infill stops at major roads are desirable.

This is good for integration not just with buses but also with cars, the preferred station access mode for American commuter rail. The LIRR’s stations are poorly located within the Long Island road network; Patrick O’Hara argues that Hicksville is the second busiest suburban station (after Ronkonkoma) not because it preferentially gets express service on the Main Line, but because it has by far the best north-south access by road, as it has one arterial heading north and two heading south, while most stations miss the north-south arterials entirely.

Instead of through-access by bus (or by car), some stations have bus bays for terminating buses. This is acceptable, provided the headways are such that the entire local bus network can be configured to pulse at the train station. If trains arrive every half hour (or even every 20 minutes), then timed transfers are extremely valuable. In that case, allowing buses to stop at a bay with fast access to the platforms greatly extends the train station’s effective radius. However, this is of far less value on a dense network with multiple parallel lines, or on a railroad so busy that trains arrive every 10 minutes or less, such as the RER A branches or the trunks of the other RER lines.

Within New York, we see this mistake of ignoring local transit in commuter rail planning with Penn Station Access. The project is supposed to add four stations in the Bronx, but there will not be a station at Pelham Parkway, the eastern extension of Fordham Road carrying the city’s busiest bus, the Bx12. This is bad planning: the MTA should be encouraging people to connect between the bus and the future commuter train and site stations accordingly.

Street networks and route choice

On a grid, this principle is on the surface easy: rapid transit routes should follow the most important routes, with stops at cross streets. This is well understood in New York (where proposals for subway extensions generally follow busy bus routes, like Second Avenue, Nostrand, and Utica) and in Vancouver (where the next SkyTrain extension will follow Broadway).

However, there remains one subtlety: sometimes, the grid makes travel in one direction easier than in another. In Manhattan, north-south travel is easier than east-west travel, so in isolation, east-west subways connecting to north-south buses would work better. (In reality, Manhattan’s north-south orientation means north-south subways are indispensable, and once the subways exist, crossing subways should aim to connect to them first and to surface transit second.) In West Los Angeles, there is a multitude of east-west arterials and a paucity of north-south ones, which means that a north-south subway is of great value, connecting not just to the Expo Line and upcoming Wilshire subway but also other east-west arterials carrying major bus routes like Olympic.

Moreover, some cities don’t have intact grids at all. They have haphazard street networks, with some routes suitable for arterial buses and some not. This is less of an issue in mature cities, which may have such street networks but also have older subway lines for newer route to connect to, and more in newer cities, typically in the third world.

The tension is that very wide arterials are easier to build on, using elevated construction or cut-and-cover. If such a technique is feasible, then constructibility should trump connections to buses (especially since such cities are fast-changing, so there is less certainty over what the major future bus routes are). However, if deep boring is required, for examples because the arterials aren’t that wide, or the subway must cross underwater, or merchant opposition to cut-and-cover is too entrenched, then it’s useful to select routes that hit the arterials orthogonally, for the best surface transit connections.

Conclusion

In a working transit city, rail should be the primary mode of travel and buses should be designed to optimally feed the trains. However, this does not mean rail should be planned without regard to the buses. Train stations should be sited based not just on walk sheds and major destinations but also planned bus connections; on an urban rapid transit system, including S-Bahn trunks, this means crossing arterial streets, where buses typically run. Moreover, these stations’ exits should facilitate easy transfers between buses and trains, including for people with disabilities, who face more constrained mobility choices if they require elevator access. In some edge cases, it may even be prudent to select entire route construction priorities based on bus connections.

While choosing rail routes based on bus connections seems to only be a real issue in rare circumstances (such as the West LA street network), bus-dependent station siting is common. Commuter train services in general are bad at placing stations for optimal suburban bus connections, and may require extensive realignment and infill. On urban subways, station placement is important for both accessibility retrofits and new projects. Outside city centers, where dense subway networks can entirely replace surface transit, it’s critical to select station sites based on maximum connectivity to orthogonal surface lines.

Port Authority’s LaGuardia Rail Link Study

Two days ago, Port Authority put out a study about a rail link to LaGuardia, which became Governor Cuomo’s top transit priority a few years ago. The PDF file is bundled with the RFP, but starting on PDF-p. 25 it’s an alternatives analysis and not an RFP. While transit activists including myself have attacked Cuomo’s proposed rail link for its poor alignment choice, the Port Authority study considers many alternatives, including some interesting ones. It also describes the current situation in more detail than I’ve seen elsewhere. I’d like to talk about the alternatives for a rail link, but also summarize some of the important facts buried in the study. Unfortunately, the study also eliminates all the useful options and prefers to advance only Cuomo’s uselessly circuitous alignment.

The current situation

LaGuardia had about 25 million O&D passengers in 2017. They disproportionately go to or from Midtown, but it’s not as overwhelming as I thought based on this density map. Here is a precise breakdown, lumping together both locals (33%) and visitors (67%):

In Manhattan and western Queens “Walking access” means half a mile from a commuter rail stop or from the 7 train; there is no attempt to track walk access to the N or W trains. In Eastern Queens it means half a mile from any subway stop.

About half of the passengers get to or from the airport by taxi, and another 20% are dropped off or picked up in a car. Only 6.2% use public transportation, and another 5.6% use a shared ride such as a hotel shuttle.

Among employees, the situation is different. I expected employees to cluster in western and central Queens, but in fact, based on the same categories used for passengers, the largest group is Queens East beyond subway range:

There are 13,000 employees at LaGuardia per Port Authority (compared with about 10,000 per OnTheMap), of whom 40% take transit to work and 57% drive. It goes without saying that the transit options are exceedingly harsh. The connections from Brooklyn require taking a subway through Manhattan (and I don’t think LGA is necessarily important enough to justify a direct bus route from Brooklyn, presumably a merger of the B38 with a Q18/Q47 compromise route to the airport). From Queens beyond subway range they require taking a bus to the subway and then another bus. The implication is that people take transit to the airport out of necessity – that is, poverty – and not because the options are good.

Unfortunately, the implication is also that it’s hard to serve the current employee base by any rail link, even if it’s fare-integrated with the subway (unlike the JFK AirTrain). The origins are too dispersed. The best that can be done is serving one tranche of origins, and letting passengers sort themselves based on commute possibilities.

In some strategic places, a decent two-seat ride can be made available. The M60 bus is not good for passengers, but it is fine for employees since more of them come from Upper Manhattan and the Bronx, and moreover low incomes imply that it’s fine to have a transit : car trip time ratio well in excess of 1 provided it’s not too onerous. Some future rail extensions, not covered in the study, would help with passenger distribution: Triboro RX would help get passengers from the South Bronx, Brooklyn, and parts of Queens to major transfer points at Astoria and Jackson Heights, and Penn Station Access with an Astoria stop would help get eastern Bronx passengers into Astoria with a quick transfer.

The alternatives analyzed

The study mentions a horde of different options for connecting people to the airport, but most only get a few paragraphs followed by an indication that they don’t meet the objectives and therefore should not be considered further. These excluded alignments exist only for i-dotting and t-crossing, such as ferries or whatever Elon Musk is calling his tunnels this year; Port Authority is right to reject them.

The alternatives proposed for further consideration consist of no build, subway extensions, and various air train alignments. Unfortunately, on second pass, the subway extensions are all eliminated, on the same grounds of community impact. This includes the least impactful subway extension, going north on 31st Street and then east on 19th Avenue, avoiding Ditmars (which could host an el).

Instead of a subway extension, the study is recommending an air train. There are many alternatives analyzed: one from Astoria along the Grand Central Parkway, one from Woodside with a connecting to the local M/R trains on the Queens Boulevard Line at Northern Boulevard, one from Jackson Heights, one from Jamaica with a missed connection to the 7, and one from Willets Point as recommended by Cuomo. All but the last are excluded on the same grounds of impact. Any land acquisition appears to be prohibited, no matter how minor.

What went wrong?

The obvious answer to why the study recommends the Willets Point detour is political support. This can be seen in e.g. PDF-p. 150, a table analyzing each of the air train possibilities. One of the criteria is operational concerns. The Jamaica option fails that test because it is so circuitous it would not get passengers between the airport and either Penn Station or Grand Central in thirty minutes. The Willets Point option passes, despite being circuitous as well (albeit less so); it would still not get passengers to Midtown Manhattan in thirty minutes since the 7 is slow, but the study seems to be assuming passengers would take the LIRR, on the half-hourly Port Washington Branch.

This alone suggests political sandbagging. But by itself it doesn’t explain how the study’s assumptions sandbag the options the governor doesn’t favor; after all, there could be many little omissions and judgment calls.

Rather, I propose that the study specifically looked only at nonstop service to the airport. The subway extensions are all proposed as nonstop services from Astoria (either Astoria Boulevard or Ditmars) to the airport, without intermediate stops. Without intermediate stops, the political will to build els above neighborhood streets is diminished, because few people in Astoria have any need to travel to LaGuardia. In contrast, with intermediate stops, the subway extensions would improve coverage within Astoria, serving Steinway and Hazen Streets.

If intermediate stops are desired, then 19th Avenue may not be the best corridor. Ditmars itself is feasible (with some takings), as are 21st and 20th Avenues. Ditmars has the most impact but serves the highest-value location, and can descend to Grand Central Parkway to get to the airport without any tunneling, limiting costs.

Moreover, the impact of els can be reduced by building them on concrete columns rather than all-steel structures. Paris Metro Line 2 opened in 1903, before the First Subway in New York; it has a steel structure on top of concrete columns, and the noise level is low enough that people can have conversations underneath while a train is passing. New Yorkers should be familiar with the reduced noise of concrete structures since the 7 el on top of Queens Boulevard is quiet, but that is an all-concrete structure on a very wide street; Line 2 here follows wide boulevards as well but not so wide as Queens Boulevard, and is moreover a mixture of concrete and steel, and yet manages not to have the screeching noise New Yorkers are familiar with from Astoria, Woodside, and other neighborhoods with els.

Is this study valuable?

Yes and no. Its conclusions should be tossed for their limited scope (nonstop airport access only), questionable assumptions (overreliance on infrequent commuter rail), and political aims (justifying Cuomo’s decision). But some of the underlying analysis, especially of current travel patterns, is useful for the purposes of thinking about systemwide transit expansion. Despite the consideration of an N/W extension, the study does not try to figure out the percentage of travelers whose ultimate origin or destination is near an N/W stop, only near a 7 stop; however, we can make some educated guesses from the map and realize that an N/W extension is of considerable value to passengers.

For employees, the situation is more delicate. The study mentions them but doesn’t try to optimize for them – the aim is to give Cuomo political cover, not to design the best possible public transit for New York. But the dispersal of worker origins means that a single rail link to the airport is unlikely to have much of an effect. Better everywhere-to-everywhere transit is needed. With decent bus connections at Astoria and Jackson Heights, it’s more important to build circumferential transit there (that is, Triboro) than to connect directly to the airport.

A general program of transit expansion would serve both groups. An N/W extension through Astoria with intermediate stops would give the neighborhood better coverage while also connecting the airport with Manhattan destinations, with good transfers to origins on the Upper East and West Sides. Better circumferential transit would then let workers from different parts of the city use the same extension without having to detour through Midtown even if their origins are in the Bronx or Queens.

Can any of this happen? The answer is unambiguously yes. Even in New York, els and at-grade rail is not so expensive. The only real question is whether good transit can happen while the state is governed by a do-nothing administration, headed by a governor who is more interested in a signature project than in improving transportation for his hapless subjects.

Heterogeneity of Preferences

The public transit conversation is full of statements like “passengers don’t like to transfer,” or, in quantified terms, “passengers perceive a minute transferring to be equivalent to 1.75 minutes on a moving vehicle.” But what does this exactly mean? It’s not a statement that literally every passenger has a transfer penalty factor of 1.75. Different passengers behave differently. At best, it’s a statement that the average passenger on the current system has a transfer penalty factor of 1.75, or alternatively that the aggregate behavior of current passengers can be approximated by a model in which everyone has a transfer penalty factor of 1.75. Understanding that different people have different preferences is critical to both the technical and political aspects of transportation planning.

I talked about the heterogeneity of transfer penalties three years ago, and don’t want to rewrite that post. Instead, I want to talk more broadly about this issue, and how it affects various transit reforms. In many cases, bad American transit practices are the result not of agency incompetence (although that happens in droves) but of preferential treatment for specific groups that have markedly different preferences from the average.

Disabilities

The universal symbol of disability is the wheelchair. Based on this standard, every discussion of accessible to people with disabilities centers people in wheelchairs, or alternatively retirees in walkers (who tend to make sure of the same infrastructure for step-free access).

However, disabilities are far broader, and different conditions lead to dramatically different travel preferences. One paper by the CDC estimates that 20% of US adults have chronic pain, and 8% have high-impact chronic pain, limiting their life in some way. People with chronic pain are disproportionately poor, uneducated, and unemployed, which should not be a surprise as chronic pain makes it hard to work or go to school (in contrast, the one unambiguously inborn socioeconomic factor in the study, race, actually goes the other way – whites have somewhat higher chronic pain rates than blacks and Hispanics). Another paper published by BMJ is a meta-analysis, finding that depending on the study 35-51% of the UK population has chronic pain and 10-14% has moderately to severely disabling chronic pain.

I’ve only talked to a handful of people with chronic pain – all of working age – and the best generalization that I can make is that it is impossible to generalize. The conditions vary too much. Some find it more painful to drive than to take transit, some are the opposite. Some have conditions that make it hard for them to walk, some are fine with walking but can’t stand for very long. To the extent the people I’ve talked to have common features, they a) have a strong preference for rail over bus, and b) require a seat and can’t stand on a moving vehicle for very long.

Work status

The best use case for rapid transit is getting people to work in a congested city center at a busy time of day, ideally rush hour. Off-peak ridership is generally cheaper to serve than peak ridership, but this is true for all modes of transportation, and public transit tends to be relatively better at the peak than cars. Per table 2 of the Hub Bound report, as of 2016, 19% of public transit riders entering the Manhattan core do so between 8 and 9 am and 43% do so between 7 and 10 am, whereas the corresponding proportions for drivers are 6% and 18% respectively.

The upshot is that people are more likely to ride public transit if they work a salaried job. This is especially true in the middle class, which can afford to drive, and whose alternative is to work at some suburban office park where car ownership is mandatory. In the working class, the distribution of jobs is less CBD-centric, but the ability to afford a car is more constrained.

The social groups most likely to drive are then neither the working class (which doesn’t own cars anywhere with even semi-reasonable public transit) nor the professional working class, but other social classes. The petite bourgeoisie is the biggest one: small business owners tend to drive, since they earn enough for it, tend to have jobs that either virtually require driving (e.g. plumbers) or involve storefronts that are rarely located at optimal locations for transit, and need to go in and out at various times of day.

Another group that’s disproportionately likely to drive is retirees. They don’t work, so they don’t use transit for its most important role. They take trips to the hospital (which is bundled with issues of disability), which can be served by buses given that hospitals are major job centers and non-work travel destinations, but their other trips tend to be based on decades of socialization that have evolved haphazardly. The urban transit network isn’t likely to be set up for their particular social use cases.

Consensus for whomst?

I bring up small business owners and retirees because these two groups are especially empowered in local politics. When I lived in Sweden, I could vote in the local and regional elections, where I had no idea what the main issues were and who the candidates were; I voted Green based on the party’s national platform, but for all I know it’s not great on Stockholm-specific issues. Figuring out the national politics is not hard even for a newcomer who doesn’t speak the language – there are enough English-language news sources, there’s social media, there are friends and coworkers. But local politics is a mystery, full of insider information that’s never spelled out explicitly.

What this means is that the groups most empowered in local politics – that is, with the highest turnouts, the most ability to influence others in the same constituency, and the greatest ability to make consistent decisions – are ones that have local social networks and have lived in one place for a long time. This privileges older voters over younger voters, and if anything underprivileges people with disabilities, whose ability to form social and political connections is constrained by where they can go. This also privileges people with less mobile jobs – that is, shopkeepers rather than either the professional middle class or the working class.

With their greater local influence, the most empowered groups ensure the transportation that exists is what is good for them: cars. Public transit is an afterthought, so of course there is no systemwide reorganization – that would require politicians to care about it, which interferes with their ability to satisfy the politically strongest classes. But even individual decisions of how to run transit suffer from the same problem when there is no higher political force (such as a strong civil service or a national political force): bus stops are very close together, transfers are discouraged (“we oppose the principle of interchange” said one left-wing group opposed to Jarrett Walker’s bus redesign in Dublin), rail service is viewed more as a construction nuisance than a critical mobility service, etc.

Models for transportation usage take into account the behavior of the average user – at least the average current user, excluding ones discouraged by poor service. However, the political system takes into account the behavior of the average empowered voter. In the case of local politics, this average voter rarely rides public transit. When city political machines run themselves, the result is exactly what you’d think.