# What are the Strong Tramway Corridors?

Note on definitions: for the purposes of this post, a tramway is a light rail line that runs predominantly on streets, interfacing with cross-traffic even if it has signal priority. It can be a legacy streetcar in mixed traffic, or a newer light rail line running on dedicated lanes. It is distinguished from lines that have substantial grade-separated segments, including subway-surface lines, where these segments are in city center while the suburban segments are in tramway mode, and tram-trains and most North American light rail lines, where these segments are in the suburbs while the city-center segments are in tramway mode.

Intermediate in capacity between the surface bus and the rapid transit train is the tram. Running on the street, perhaps with signal priority but without the absolute priority that mainline trains have at grade crossings, trams are still surface transit, but feature better ride quality, generally higher capacity in terms of vehicles per hour, and generally bigger vehicles. A number of cities have been building such transit in recent years, most notably Paris, which has been making the rounds on the Transit Center for having almost a million daily riders on its system. The Transit Center gives various recommendations based on Paris’s success, but those recommendations – frequency, fare integration, good transfers – say very little about where a city should be building tramway lines. In this post, I am going to sketch features of good corridors for tramways.

1. Tramways are surface transit

There are various features that make for good surface transit routes. Jarrett Walker, who has extensive experience in bus network redesigns, outlined some of them in a network design document he collaborated on for TransLink. These include high density along the route, relatively balanced demand in both directions, and the potential for a strong everywhere-to-everywhere grid. Additional important features of strong bus routes: a single street with few twists, since turns slow down surface vehicles a lot, and swerving to reach major destinations is often cumbersome; and a wide street, since in practice few cities will give transit dedicated lanes if there’s not enough room for cars as well. These rules do not apply to subways, which can zigzag between different streets or carve a new alignment. However, they do apply to tramways.

2. The strongest bus corridors are in most need of investment

In a city where the buses that can support high frequency already are frequent, the highest potential for extra ridership is on routes that are already strong. Imagine a bus that averages 15 km/h: replacing it with a 20 km/h tram that provides a smoother and more reliable ride has benefits in rough proportion to existing bus ridership. Since both buses and trams are surface transit and follow the same rules, it’s unlikely that there are routes that would make good trams but poor buses. This is in stark contrast with subways, where a potentially strong corridor may not have a continuous surface right-of-way for high bus ridership. On the surface, this corridor could not succeed as either a bus or a tram. This is a specification of the BMT’s all four concept (bus, trolleybus, tramway, subway), in which the four modes work in complement, and the busiest routes in each category are upgraded to the next based on a tradeoff between construction costs and operating costs.

3. In a city with subways, the tramways should be placed on routes that would make poor subway corridors

It goes without saying that tramways should not duplicate subways. But more than that, if a bus route is so strong that it’s a potential subway extension, it should not be turned into a tram. At first pass, this may look like the best bus routes to be turned into trams are not quite the busiest, but the next tier of busier buses. However, this has to do not just with ridership, but also layout relative to the subway system. The subway is almost invariably radial, so strong buses that make easy radials or branches of radials would be strong subway routes, while circumferential buses would not. A radial bus may also turn out to be a poor subway route, if it happens to point in a direction where a subway wouldn’t be a good fit, but this is less likely.

4. A connected network is beneficial, but not required

Ideally, all light rail routes – not just tramways, but also subway-surface routes and tram-trains if they exist – should form a connected graph, with track connections, to enable maximum flexibility in yard placement and reduce the required spare ratio. However, this is not a requirement. Large, busy systems in particular may economically have a yard serving just 1-2 lines, in which case the value of connectedness decreases. In conjunction with point #3, cities with large radial subway networks may have disconnected circumferential tramways, including Paris.

5. When there’s a choice between several tramways and a subway, tramways work better when there’s no dominant route

The construction cost of a subway, in developed countries that are not the US, is $100-300 million per km, with outliers outside the range in both directions. The construction cost of a tramway in the same countries is$15-50 million per km, again, with outliers. The choice of whether to build one subway or six tramways depends on how busy the strongest route is relative to the next five routes. If two strong bus routes are closely parallel, then both should be reckoned together for subway ridership estimates (and to some extent also for tram ridership), since people walk longer to better service, in this case a fast subway rather than a slow bus. Another consideration, more about construction costs than ridership, is whether there exists a good right-of-way for the subway, perhaps an abandoned or low-ridership commuter line that can be converted, that would make it possible to limit tunneling.

Examples

Boston has few long, wide roads; Massachusetts Avenue is one of very few exceptions. Downtown Boston and the surrounding neighborhoods have very narrow streets, which is why the Boston bus network is sparse downtown – the buses feed outlying subway stations, or stop at the edge of the central business district at Haymarket, and almost never enter the downtown core. Because of the Green Line, some strong radial routes, such as the Washington Street half of the Silver Line, and the 23 bus on Blue Hill Avenue, are naturally good extensions of the subway-surface network; they’d make good light rail, but not all-surface tramways.

In strongly gridded cities, including Chicago, Vancouver, Toronto, and Los Angeles, it doesn’t make too much sense to build individual tramways; instead, the entire frequent bus grid could be so upgraded, or possibly just the lines that are perpendicular to the rapid transit system in Chicago and Toronto. Unfortunately, this runs into high construction costs, which leads to questions of priorities: build an expansive light rail network, or extend a few subway lines.

I believe Los Angeles and Vancouver are doing right in choosing to prioritize subways on their strongest corridors. Vancouver in particular is an extreme example of point #5 pointing toward a subway, with 80,000 weekday riders on Broadway and another 40,000 on the routes interlining on 4th Avenue 500 meters away (not all on 4th, as two of the four 4th Avenue routes have substantial tails elsewhere), compared with 110,000 on the next five routes combined; Vancouver also seems to have an unusually low subway-to-tram cost ratio, only about 2.7 rather than 6. Los Angeles has a less extreme version of point #5, but Wilshire and very close-by routes dominate east-west traffic, and can also easily feed into the existing subway.

In Chicago, the circumferential nature of the top bus routes – north-south west of the Loop, east-west north and south of it – makes an L extension infeasible, so from point #3, any solution has to involve surface transit. The current plan is dedicated bus lanes. In Toronto this decision is more difficult, and acrid debates between a mostly-surface option and an all-underground option led to the latter choice, influenced by Rob Ford’s unwillingness to take road lanes from cars; right now Toronto is building one subway line (update: it’s mixed subway-surface), under Eglinton, and one tramway, on Finch West.

New York

In New York, Bill de Blasio proposed a tram route near the Brooklyn and Queens waterfront earlier this year; see background articles here and here. This route is ill-suited for the technology proposed, or for any significant investment. The buses along the waterfront are all quite weak. In both Brooklyn and Queens, the busiest buses are in the interior, some going perpendicular to the subway, such as the Q44 on Main Street and B35 on Church, and some serving radial routes that have long been planned to be subway extensions, namely the B46 on Utica and B44 on Nostrand. Select Bus Service investments have targeted these routes, and now the Q44, B44, and most recently the B46 all have SBS features.

Another weakness of the proposed route is that it subtly combines circumferential and radial service; see here for why this is poor practice. While the line is for the most part straight, the north-south segment in Queens is essentially radial, going from Astoria to Long Island City, parallel to the N/Q subways, before switching to circumferential between Long Island City and Downtown Brooklyn. South of Downtown Brooklyn it becomes radial again, connecting to Red Hook and Sunset Park. Riders in Astoria going south are mostly interested in continuing toward Manhattan and not toward Brooklyn; riders in Sunset Park and Red Hook going north would first of all follow different routes (Sunset Park already has the N and R subways and has no use for a detour through Red Hook), and second of all be more interested in going to Manhattan and to Williamsburg and points north.

While de Blasio’s proposal is bad transit, there are routes in New York that could make strong tramways. None of them is on the city’s redevelopment agenda, based on the principle that US cities almost never invest in low- and lower-middle-income neighborhoods except when they are about to gentrify, but the bus ridership there is solid, even though the buses crawl.

The busiest routes in New York are the M15 on 1st and 2nd Avenues in Manhattan, the B46, and the Bx12 on Fordham Road; each has been the single busiest in one of the last few years, but usually the M15 is first. The first two are strong subway routes: the first phase of Second Avenue Subway will soon open, and the rest will be built when the city can find multiple billions per kilometer for them; Utica is also a strong route, and de Blasio proposed it last year before abandoning the idea. But Fordham satisfies point #4 perfectly: it is circumferential, and can only realistically extend the A train, already the system’s longest route, with a mismatch in potential ridership between the core radial segment and what a Fordham subway would get. The Bx12 was the first route to be turned into SBS, and is either the strongest potential tramway in the city, or one of the few strongest.

Going further down the list, we should eliminate the strong Brooklyn routes, except the B41 on Flatbush. The B44 is also a potential subway extension, and the three busiest circumferentials – the B6, B35, and B82 – all parallel the Triboro right-of-way, which by point #5 is a superior project to building multiple light rail lines. The busiest bus in Queens, the Q58, has a long segment between Queens and Brooklyn, about half its total length, that would be obviated by Triboro as well.

The B41 could be a tramway going between City Hall and Kings Plaza, using two dedicated lanes of the Brooklyn Bridge. In that case, the line would effectively act as subway-surface, or more accurately elevated-surface: a surface segment in Brooklyn, a grade-separated segment between Manhattan and Brooklyn. Subway-surface lines should branch, as all current examples do (e.g. Boston Green Line, Muni Metro, Frankfurt U-Bahn), because the subway component has much higher capacity than the surface components. This suggests one or two additional routes in Brooklyn, which do not have strong buses, but may turn into strong tramways because of the fast connection across the river to Manhattan. The first is toward Red Hook, which is not served by the subway and cut off from the rest of the city by the Gowanus Expressway. Unfortunately, there is no really strong corridor for it – the streets are not very wide, and the best for intermediate ridership in Cobble Hill and Carroll Gardens require additional twists to get into the core of Red Hook. Court Street might be the best compromise, but is annoyingly a block away from the F/G trains, almost but not quite meeting for a transfer. The second possible route is along Flushing Avenue toward the Navy Yard; it’s not a strong bus by itself, but the possibility of direct service to Manhattan, if a Flatbush tramway preexists, may justify it.

In the Bronx and Queens, a more conventional network is called for. The Bronx in particular has several strong bus lines forming a good grid, in addition to the Bx12. The east-west routes cannot possibly be made into subway extensions, while the north-south ones have nowhere to go to in Manhattan except possibly a Second Avenue Subway extension, and even that is doubtful (if there’s money to extend Second Avenue Subway north, it should instead go west under 125th Street). A light rail grid could consist of the Bx12 as outlined above, a Tremont line acting as a compromise between the Bx36 and Bx40/42 feeding into Manhattan on 181st Street, a 161st/163rd Street route going into Manhattan on 155th Street replacing the Bx6, a Southern/Manhattan 145th Street route along the Bx19, a Third Avenue route along the Bx15, and a Grand Concourse route along the Bx1/2. Grand Concourse has a subway, but the Bx1/2 nonetheless currently ranks 5th in the city in weekday ridership, and the street is so wide that it’s a good candidate for light rail. Update: a Webster Avenue route along the Bx41 is also feasible, I just forgot it when writing this post.

In Queens, there’s less room for a grid. Main Street is a strong route, connecting to Tremont in the Bronx via the Whitestone Bridge, as the Q44 SBS already does today. A second route between Flushing and Jamaica, on Kissena and Parsons, could also get a tramway. These two routes are uniquely bad subways, since they connect two busy subway lines, both of which could be extended past their termini outward. The main route on Kissena, the Q25, and another route slightly farther east, the Q65, rank 3rd and 2nd among the MTA buses, separate from the New York City Transit buses, with about 20,000 weekday riders each; they also continue north to College Point, which could get a tramway, or perhaps even a subway extension of the 7, depending on whether there are plans to redevelop the Flushing Airport site.

If there is not enough ridership on both Kissena and Main, then only Main should be turned into light rail. More potential corridors include the Q46 on Union Turnpike and the Q10 on Lefferts going to JFK (the busiest MTA bus). Unfortunately, Queens buses tend to be on the long side, e.g. the Q27, the borough’s number 3 bus after the Q58 and Q46, is 15 km long; in the Bronx the longest, Tremont, would be 13 km, cobbled out of busier buses, and most are about 10 km. The Q44 is even longer, at 20 km; light rail is only justified there because of extra local ridership coming from the Q20 local and from the fact that the Queens-Bronx segment over the bridge would be rapid transit. Even then, the tramway may only be justified from Flushing south.

I don’t want to make recommendations for priorities and an exact fantasy map in New York, as those depend on construction costs and the available budget. Fordham and Main Street are most likely the two strongest initial choices. Judging by the cost estimate for de Blasio’s waterfront proposal, tramways in New York are about $60-70 million per km, which in an inverse of the situation in Vancouver leads to an unusually high subway : tram cost ratio, 25 if we take the Manhattan subway extensions (Second Avenue and the 7 extension) as our examples, probably less but not much less if we look at a hypothetical Utica subway. This should bias New York rail extensions toward surface transit. De Blasio proposed$1.5 billion for about 25 km of tramway on the waterfront. The waterfront idea is bad, and money can and should go elsewhere; 25 km is slightly longer than the combined length of the Bx12 and the B46 from Flushing south. Those two together could be the start of a program to bring surface rail back to New York, using the same routing reasoning that made Paris’s program so successful. Using ridership on the existing buses and adjusting upward for rail bias, initial ridership on those two lines combined should be higher than 100,000 per day, and with more lines and a bigger network, fast multiplication of overall traffic can be expected.

# Greenbelts Help Cars

A number of major cities, most notably London, have designated areas around their built-up areas as green belts, in which development is restricted, in an attempt to curb urban sprawl. The towns within the green belt are not permitted to grow as much as they would in an unrestricted setting, where the built-up areas would merge into a large contiguous urban area. Seeking access to jobs in the urban core, many commuters instead live beyond the greenbelt and commute over long distances. There has been some this policy’s effect on housing prices, for example in Ottawa and in London by YIMBY. In the US, this policy is less common than in Britain and Canada, but exists in Oregon in the form of the urban growth boundaries (UGBs), especially around Portland. The effect has been the same, replacing a continuous sprawling of the urban area with discontinuous suburbanization into many towns; the discontinuous form is also common in Israel and the Netherlands. In this post, I would like to explain how, independently of issues regarding sprawl, such policies are friendlier to drivers than to rail users.

Let us start by considering what affects the average speed of cars and what affects that of public transit. On a well-maintained freeway without traffic, a car can easily maintain 130 km/h, and good cars can do 160 or more on some stretches. In urban areas, these speeds are rarely achievable during the day; even moderate traffic makes it hard to go much beyond 110 or 120. Peak-direction commutes are invariably slower. Moreover, when the car gets off the freeway and onto at-grade arterial roads, the speed drops further, to perhaps 50 or less, depending on density and congestion.

Trains are less affected by congestion. On a well-maintained, straight line, a regional train can go at 160 km/h, or even 200 km/h for some rolling stock, even if headways are short. The busiest lines are typically much slower, but for different reasons: high regional and local traffic usually comes from high population density, which encourages short stop spacing, such that there may not be much opportunity for the train to go quickly. If the route is curvy, then high density also makes it more difficult to straighten the line by acquiring land on the inside of the curves. But by and large, slowdowns on trains come from the need to make station stops, rather than from additional traffic.

Let us now look at greenbelts of two kinds. In the first kind, there is legacy development within the greenbelt, as is common around London. See this example:

The greenbelt is naturally in green, the cities are the light blue circles with the large central one representing the big city, and the major transportation arteries (rail + freeway) are in black. The towns within the greenbelt are all small, because they formed along rail stops before mass motorization; the freeways were built along the preexisting transportation corridors. With mass motorization and suburbanization, more development formed right outside the greenbelt, this time consisting of towns of a variety of sizes, typically clustering near the freeways and railways for best access to the center.

The freeways in this example metro area are unlikely to be very congested. Their congestion comes from commuters into the city, and those are clustered outside the greenbelt, where development is less restricted. Freeways are widened based on the need to maintain a certain level of congestion, and in this case, this means relatively unimpeded traffic from the outside of the green belt right up until the road enters the big city. Under free development, there would be more suburbs closer to the city, and the freeway would be more congested there; travel times from outside the greenbelt would be longer, but more people would live closer to the center, so it would be a wash.

In contrast, the trains are still going to be slowed down by the intermediate stops. The small grandfathered suburbs have no chance of generating the rail traffic of larger suburbs or of in-city stops, but they still typically generate enough that shutting them down to speed traffic is unjustified, to say nothing of politically impossible. (House prices in the greenbelt are likely to be very high because of the tight restrictions, so the commuters there are rich people with clout.) What’s more, frequency is unlikely to be high, since demand from within the greenbelt is so weak. Under free development, there might still be more stops, but not very many – the additional traffic generated by more development in those suburbs would just lead to more ridership per stop, supporting higher frequency and thus making the service better rather than worse.

Let us now look at another greenbelt, without grandfathered suburbs, which is more common in Canada. This is the same map as before, with the in-greenbelt suburbs removed:

In theory, this suburban paradigm lets both trains and cars cruise through the unbuilt area. Overall commutes are longer because of the considerable extra distance traveled, but this distance is traversed at high speed by any mode; 120 km/h is eminently achievable.

In practice, why would there be a modern commuter line on any of these arteries? Commuter rail modernization is historically a piecemeal program, proceeding line by line, prioritizing the highest-trafficked corridors. In Paris, the first commuter line to be turned over to the Metro for operation compatible with city transit, the Ligne de Sceaux, has continuous urban development for nearly its entire length; a lightly-trafficked outer edge was abandoned shortly after the rest of the line was electrified in 1938. If the greenbelt was set up before there was significant suburbanization in the restricted area, it is unlikely that there would have been any reason to invest in a regional rail line; at most there may be a strong intercity line, but then retrofitting it to include slower regional traffic is expensive. Nor is there any case for extending a high-performing urban transit line to or beyond a greenbelt. Parts of Grand Paris Express, namely Lines 14 and 11, are extended from city center outward. In contrast, in London, where the greenbelt reduces density in the suburbs, high investment into regional rail focuses on constructing city-center tunnels in Crossrail and Crossrail 2 and connecting legacy lines to them. In cities that do not even have the amount of suburban development of the counties surrounding London, there is even less justification for constructing new transit.

The overall picture in which transit has an advantage over cars at high levels of density is why high levels of low-density sprawl are correlated with low transit usage. But I stress that even independently of sprawl, greenbelts are good for cars and bad for transit. A greenbelt with legacy railway suburbs is going to feature trains going at the normal speed of a major metro area, and cars going at the speed of a more spread out and less populated region. Even a greenbelt without development is good urban geography for cars and bad one for transit.

As a single exception, consider what happens when a greenbelt is reserved between two major nodes. In that specific case, an intercity line can more easily be repurposed for commuting purposes. The Providence Line is a good example: while there’s no formal greenbelt, tight zoning restrictions in New England even in the suburbs lead to very low density between Boston and Providence, which is nonetheless served by good infrastructure thanks to the strength of intercity rail travel. The MBTA does not make good use of this infrastructure, but that’s beside the point: there’s already a high-speed electrified commuter line between the two cities, with widely spaced intermediate stops allowing for high average speeds even on stopping trains and overtakes that are not too onerous; see posts of mine here and here. What’s more, intercity trains can be and are used for commutes from Providence to Boston. For an analogous example with a true greenbelt, Milton Keynes plays a role similar to Providence to London’s Boston.

However, this exception is uncommon. There aren’t enough Milton Keyneses on the main intercity lines to London, or Providences on the MBTA, to make it possible for enough transit users to suburbanize. In cities with contiguous urban development, such as Paris, it’s easier. The result of a greenbelt is that people who do not live in the constrained urban core are compelled to drive and have poor public transportation options. Once they drive, they have an incentive to use the car for more trips, creating more sprawl. This way, the greenbelt, a policy that is intended to curb sprawl and protect the environment, produces the exact opposite results: more driving, more long-distance commuting, a larger urban footprint far from the core.

# The RPA Continues to Push for the Flawed Crossboro Plan

As the Regional Plan Association continues to work on its Fourth Regional Plan, expected to be published next year, it’s releasing various components of the upcoming agenda. One, an update from the Third Regional Plan from 1996, is a line variously called Triboro or Crossboro. In the third plan, Triboro RX was meant to be a circumferential subway line, taking over existing abandoned and low-traffic freight rail rights-of-way in Brooklyn, Queens, and the South Bronx, terminating at Yankee Stadium via a short tunnel. It was never seriously proposed by any political actor, but was briefly mentioned positively by then-MTA chair Lee Sander in 2008, and negatively mentioned by Christine Quinn, who called for a bus line along a parallel alignment in her mayoral campaign in 2013. In 2014, Penn Design proposed a variant it calls Crossboro, which differs from the original Triboro proposal in two ways: first, the stop spacing is much wider, and second, instead of the short tunnel to Yankee Stadium, it continues northeast along the Northeast Corridor, making four stops in the Bronx as in the proposed Metro-North Penn Station Access plan. Crossboro is an inferior proposal, and unfortunately, the fourth plan’s Triboro proposal downgrades it from the original alignment to Crossboro.

As I explained a year and a half ago, specifically in the context of Crossboro, it is poor planning to run train service that begins as a radial and then becomes as a circumferential instead of continuing into the center. The route of Crossboro, and now also the Triboro plan, involves going from the North Bronx to the south in the direction of Manhattan, but then turning southeast toward Queens and Brooklyn, rather than continuing to Manhattan. Briefly, in a system with radial and circumferential routes (as opposed to a grid), circumferential service is the most effective when it connects to secondary centers, and has easy transfers to every radial. If a line runs as a radial and then switches to circumferential, its ability to connect to other radials is compromised, making it a weaker circumferential; nor could it ever be even a half-decent radial without service to the CBD. Lines with such service pattern, such as Line 3 in Shanghai and the G train in New York until 2001, tend to underperform.

However, the stop spacing deserves to be treated separately. Under both Crossboro and the RPA’s new version of Triboro, there are too few stops for the line to be useful as an urban rail service. I’m going to ignore the connection between Queens and the Bronx, which as a major water crossing can be expected to have a long nonstop segment, and talk first about the Bronx, and then about Queens and Brooklyn.

In the Bronx, there are four stops in 10 km, starting counting from where the bridge toward Queens begins to rise. This may be reasonable for a commuter rail service with local service extending well past city limits (to New Rochelle or even Stamford), but when it terminates within the city, it’s too far for people to be able to walk to it. The proposed stops also miss the Bronx’s most important bus route, the Bx12 on Fordham Road, which in 2015 became the city’s busiest single bus route. A stop on the Pelham Parkway, the continuation of Fordham in the East Bronx, would be a massive travel time improvement over trying to reroute the Bx12 to meet a train station near Coop City, the proposed northern terminus of both Crossboro and the new Triboro. Conversely, it would delay few other passengers, by very little, since there would only be one further stop north. The result of the proposed stopping pattern is then that most people living near the line would not be able to either walk to it or take a frequent bus.

In Queens and Brooklyn, starting from Astoria and going south, the route is 26 km long, and the new Triboro makes 17 stops. The average interstation, 1.5 km, is noticeably above the international subway average, and is especially high for New York, whose stop spacing is near the low end globally. The original version had 29 stops over the same distance, and one more stop between Astoria and the bridge. Unlike in the Bronx, in Brooklyn all streets hosting major radial routes get subway stops. However, long stretches of the route get no stops. The stop spacing is not uniform – from Northern Boulevard to Grand Avenue there’s a stretch with 4 stops in 2.8 km (counting both ends), but from Astoria-Ditmars to Northern Boulevard there’s a 2.5 km nonstop service, skipping Astoria Boulevard and Steinway, passing through a medium-density neighborhood south of the Grand Central Parkway with mediocre subway access. A stop at Astoria Boulevard and Steinway is obligatory, and probably also one between Astoria and Northern, around 49th Street. To the south of Grand Avenue, the proposal calls for a 2.1 km nonstop segment to the M terminus at Metropolitan Avenue, skipping Middle Village, which is cut off from Grand by the Long Island Expressway and from the M by cemeteries. An additional stop in the middle of this segment, at Eliot Avenue, is required.

In Brooklyn, the route runs express next to the L train, splitting the difference between serving Broadway Junction (with a connection to the A/C) and Atlantic Avenue (with a connection to the LIRR): the RPA’s diagram depicts a station at Atlantic Avenue but calls it Broadway Junction. Farther south, it makes a few stops on an arc going southwest toward southern Brooklyn; the stops are all defensible, and the stop spacing could potentially work, but there are still potential missing locations, and some nonstop segments in the 1.7 km area. For example, it goes nonstop between Utica and Nostrand Avenues, a distance of 1.7 km, with a good location for an interpolating station right in the middle, at Albany Avenue. From Nostrand west, it stops at a transfer to every subway line, except the R. In that segment, one more stop could be added, between the F and the D/N; the reason is that the gap between these two lines is 1.8 km, and moreover the right-of-way slices diagonally through the street grid, so that travel time from the middle to either stop is longer along the street network. However, overall, this is not why I dislike the route. Finally, at the western end, the route is especially egregious. The right-of-way is parallel to the N train, but then awkwardly misses 59th Street, where the N veers north and starts going toward Manhattan. The original proposal had a stop several blocks away from 59th, with a long transfer to the R (and N); this one drops it, so there is no R transfer in Brooklyn – trains express from the D/N transfer at New Utrecht to the terminus at Brooklyn Army Terminal, where there is very little development. There are practically no through-riders who would be inconvenienced by adding the extra two N stops in between. In contrast, due to the low frequency of the N (it comes every 10 minutes off-peak), making passengers originating in those stations who wish to ride Triboro transfer would add considerably to their travel time.

A route like Triboro has an inherent problem in deciding what stop spacing to use, because as a circumferential, it is intended to be used on a large variety of origin-destination pairs. For passengers who intend to connect between two outer radial legs more quickly than they could if they transferred in Manhattan, the wider stop spacing, emphasizing subway connections, is better. However, the mixed radial-circumferential nature of the new Triboro makes this a losing proposition: there’s no connection to any subway line in the Bronx except the 6. Moreover, in Brooklyn, there’s no connection in Brooklyn to the R, and if there’s a connection to the A/C, it involves walking several hundred meters from what on the L is a separate subway stop.

In contrast, for passengers whose origins are along the line, narrower stop spacing works better, because they’re unlikely to cluster around the connection points with the radial subway lines. (The line has no compelling destinations, except maybe Jackson Heights and Brooklyn College; in the Bronx, the two most important destinations, the Hub and Yankee Stadium, are respectively close to and on the old Triboro route, but far from the new one.) The aforementioned Astoria/Steinway, Eliot, and Albany, as well as the skipped stations along the L and N routes, all have reasonable numbers of people within walking distance, who have either poor subway access (the first three) or only radial access (the L and N stations).

What’s more, if trains make more stops, the increase in travel time for passengers connecting between two legs is not large compared with the reduced station access time for passengers originating at an intermediate station. The reason is that passengers who connect between two legs are not traveling all the way. The fastest way to get from the West Bronx to southern Brooklyn is to take the D train all the way, or take the 4 to the D; from the 6 train’s shed, the fastest way is to take the 6 and transfer to the N/Q at Canal or the B/D at Broadway/Lafayette. No circumferential service can change that. The benefit of circumferential service is for people who travel short segments: between the Bronx and Queens, or between the 7 or the Queens Boulevard trains and the lines in Brooklyn that aren’t the F. Given high circumferential bus ridership in Brooklyn – two circumferential routes, the B6 and B35, rank 2nd and 4th borough-wide and 4th and 7th citywide, despite averaging maybe 9 km/h – connections between two Brooklyn legs are also likely. For those passengers, making a few more local stops would add very little to travel time. The subway has a total stop penalty of about 45 seconds per station. Of the ten extra stops I list as required – Astoria/Steinway, Eliot, Albany, 59th, four along the L, and two along the N – three (the two on the N and 59th) are basically end stations, and few passengers have any reason to travel over more than five of the rest. In contrast, adding these ten stops would improve the quality of transfers to the R and A/C and provide crucial service to intermediate neighborhoods, especially Middle Village.

Finally, let me make a remark about comparative costs. The original Triboro plan required a short tunnel, between Melrose Metro-North station and Yankee Stadium; the new one does not. However, a single kilometer of new tunnel in the context of a 34 km line is not a major cost driver. The new proposal is actually likely to be more expensive. It is longer because of the segment in the Bronx along the Northeast Corridor, about 40 km in total, and 10 km would be alongside an active rail line. There are plans for increased mainline passenger rail service on the line: Penn Station Access, plus any improvements that may be made to intercity rail. Far from offering opportunities to share costs, such traffic means that any such plan would require four tracks on the entire line and flying junctions to separate trains going to Penn Station from trains going to Brooklyn. Fare collection would be awkward, too – most passengers would transfer to the subway, so subway faregates would be required, but commuter rail has no need for faregates, so sharing stations with Penn Station Access would require some kludge that wouldn’t work well for any mode. Tunneling is expensive in New York, but so is at-grade construction; a kilometer of tunnel in the Bronx is unlikely to cost more than configuring an active rail mainline for a combination of suburban and high-frequency urban service.

The RPA proposes the London Overground as a model, treating the new Triboro as a commuter line offering subway service levels. Everywhere else I’d support this idea. But here, it fails. First, as I explained in a previous post, the routing is an awkward mix of radial and circumferential. But second, the stop spacing only works in the context of a long suburban line feeding city center, and not an urban circumferential line. In the context of an urban line, more stops are needed, to let people walk from more neighborhoods to the train, or take a connecting bus. For the most part, the original Triboro plan, designed around interstations of about 900 meters not counting the water crossing, would work well. Crossboro, and its near-clone the new Triboro, is inferior to it in every respect, and the RPA should jettison it from the Fourth Regional Plan in favor of the old proposal.

# Select Bus Service Problems

I recently visited New York. I stayed in Kew Gardens Hills, a neighborhood located between Jamaica and Flushing, just close enough to the subway that it’s plausible to walk but just far enough that this walk is uncomfortable and I preferred to take a bus. The bus route, Main Street, is one of Queens’ busiest (see data here and here). I’ve been calling for investment in it for years, going back to a fantasy spite map I drew so long ago I don’t remember what year it was, and continuing more recently in my post on where New York should and shouldn’t build light rail. Last year, the route did get Select Bus Service, and I took it a few times. The result is not good.

Main Street maintains two bus corridors: the local Q20, and the Select Bus Service Q44. Almost every SBS route is an overlay of a local route and a rapid route; on the local route passengers must board from the front and pay within view of the driver, and on the rapid route passengers must validate a ticket at ticketing machines beforehand and can then board the bus from any stop, with the fare enforced via random checks for ticket receipts. This leads to the following problems, some preventable, some inherent to this setup:

1. Passengers who can take either the local or the SBS route need to decide in advance whether to validate their tickets at the machines or not, based on whether the next bus is SBS. The resulting last-minute validation delays boarding. After the mayhem caused by the introduction of SBS to the M15, on First and Second Avenues, bus drivers on local routes began to accept the receipts spitted out by the SBS ticketing machines. However, this practice is either inconsistent or not widely-known among occasional bus riders, such as the people I was staying with, who own cars.
2. The combination of local and limited buses on a medium-frequency route such as Main Street makes it impossible to maintain even headways. Even within each route (Q20 or Q44) I repeatedly saw bunching, but the different speeds of the Q20 and Q44 make bunching between a local and an express inevitable at some point on the route. Off-peak weekday frequency is 10 minutes on the Q20 and 8 on the Q44, which isn’t good enough to justify this split, especially given the bunching within each route; some stations will always be scheduled to have 8-minute service gaps, and in practice could see 15-minute gaps because of the bunching. See more on this problem of locals and rapids on infrequent routes on Human Transit.
3. The expense of the ticketing machines ($75,000 per stop for a pair of modified MetroCard vending machines and a machine that takes coins) limits how widely they can be installed. Everywhere else where proof-of-payment is used, holders of valid transfers and season passes can just board the train or bus and show their pass to an inspector. This would be especially useful in New York, because the biggest crunch at SBS stops occurs when many passengers arrive at the stop at once, which in turn is the most common where passengers transfer from the subway. The slow process of validating a ticket leads to queues at busy times, and adding more machines is difficult because of their cost. 4. Stop spacing is never what it should be. Most developed countries have converged on a standard of about 400-500 meters between successive bus stops. North America instead has converged on 200 meters, leading to slow buses that stop too often; see an old Human Transit post on the subject here. The stop spacing on the segment of the Q44 I was using was two stops in 1.7 km, leading to long walks between stops. 5. On the schedule, the Q44 makes 15 stops in 9.2 km between its origin in Jamaica and Flushing, and takes 42 minutes in the midday off-peak. This is an average speed of 13.1 km/h. In contrast, Vancouver’s limited-stop buses, which average about a stop per kilometer on Broadway and 4th Avenue, average 20 km/h and 30 km/h respectively; the 4th Avenue buses do not have off-board fare collection, but there’s less traffic than on Broadway, and the stoplights give priority to through-traffic, both private and public, over crossing traffic. The basic problem with New York’s approach to Select Bus Service is that all North American bus rapid transit ultimately descends from Jaime Lerner’s sales pitch of BRT as a cheap subway on tires, at grade. Lerner implemented BRT in Curitiba successfully, in the context of low wages: construction costs appear to only weakly depend on wealth (see e.g. my posts here, here, here, here, and here), but bus driver costs rise with average income, making replacing fifteen bus drivers with one subway driver a crucial money saver in rich cities and an unaffordable luxury in poor ones. North American BRT imitates Latin American BRT’s role as a cheap subway substitute, and ignores the superior usage of bus services in Europe, with which American transit planners do not dialog; there’s no systematic dialog with Latin American planners either, but Lerner has aggressively pitched his ideas to receptive audiences, whereas no comparable figure has pitched European-style reforms to the US. In cities that think of BRT as a subway substitute, the BRT network will tend to be small, consisting of a few lines only serving the most important corridors, and bundle various features of improved transit together (off-board fare collection, larger vehicles, bus lanes, signal priority). After all, a line can’t be partly a subway and partly a bus. In Bogota, whose BRT system has eclipsed Curitiba and is the world’s largest, the BRT lines run different vehicles from the local lines: local buses have doors opening on the right to the curb, BRT buses have doors opening on the left to a street median bus station, some hybrids have buses with doors on both sides (see photos on Spanish Wikipedia). ITDP, which promotes Latin American-style BRT around the world, has a BRT scoring guideline that awards points to systems that brand their BRT lines separately from the rest of the bus network, as New York does with SBS. In the European thinking, there’s already an improved quality urban transit service: the subway, or occasionally the tram. The bus is a bus. The biggest difference is that subway networks are smaller than bus networks. Paris and London, both with vast urban rail networks, have a number of subway lines measured in the teens, plus a handful of through-running commuter services; they have hundreds of bus routes. Instead of branding a few buses as special, they invest in the entire bus network, leading to systemwide proof-of-payment in many cities. Bus lanes and signal priority are installed based on demand on an individual segment basis. New York installs bus lanes without regard to local versus SBS status, but retains the special SBS brand, distinguished by off-board fare collection, and only installs it on a per-route basis rather than systemwide. The other issue, unique to New York, is the ticket receipts. Everywhere else that I know of, bus stops do not have large ticket machines as New York does. Vancouver, which otherwise suffers from the same problem of having just a few special routes (called B-Lines), has no ticket machines at B-Line stops at all: people who have valid transfers or monthly passes can board at their leisure from any door, while people who don’t pay at the front as on local buses. SBS in contrast does not give passengers the option of paying at the front. In New York, people justify the current system by complaining that the MetroCard is outdated and will be replaced by a smart card any decade now; in reality, systems based on paper tickets (including Vancouver, but also the entire German-speaking world) manage to have proof-of-payment inspections without smartcards. Small devices that can read the MetroCard magnetic stripe are ubiquitous at subway stops, where people can swipe to see how much money they have left. The right path for New York is to announce that every bus route will have off-board fare collection, regardless of stop spacing. It should also engage in stop consolidation to reduce the interstation to about 400-500 meters, but this is a separate issue from fare collection. Similarly, the question of bus lanes should be entirely divorced from fare collection. There should be no ticketing machines at bus stops of the kind currently used. At most, stops should have validators, similar to the MetroCard readers at subway turnstiles but without the fare barrier. Validators are not expensive: smartcard readers in Singapore are consumer items, available to people for recharging their cards at home via their credit cards for about$40, a far cry from the $75,000 cost in New York today. People with valid transfers or unlimited cards should be able to board without any action, and people without should be able to pay on the bus. Finally, the split between local and rapid routes should be restricted to the busiest routes, with the highest frequency in the off-peak. Conceivably it should be avoided entirely, in favor of stop consolidation, in order to increase effective frequency and reduce bunching. The city’s single busiest route, the M15, has 7-minute SBS and 8-minute local service in the midday off-peak, and given how slow the local is, it’s enough to tip the scales in favor of walking the entire way if I just miss the bus. # Quick Note: A Hypothesis About Airport Connectors It is a truth universally acknowledged that cities spend far more per rider on airport connectors than on other kinds of public transit. On this blog, see many posts from previous years on the subject. My assumption, and that of such other transit advocates as Charles Komanoff, was always that it came from an elite versus people distinction: members of the global elite fly far more than anyone else, and when they visit other cities, they’re unlikely to take public transit, preferring taxis for most intermediate-length trips and walking for trips around the small downtown area around their hotels. In this post, I would like to propose an alternative theory. Commuters who use public transit typically use their regular route on the order of 500 times a year. If they also take public transit for non-work trips around the city, the number goes even higher, perhaps 700. In contrast, people who fly only fly a handful of times per year. Frequent business travelers may fly a few tens of times per year, still an order of magnitude less than the number of trips a typical commuter takes on transit. What this means is that 2 billion annual trips on the New York-area rail network may not involve that many more unique users than 100 million annual trips between the region’s three airports. Someone who flies a few times per year and is probably middle class but not rich might still think that transportation to the airport is too inconvenient, and demand better. In the US, nearly half the population flies in any given year, about 20% fly at least three roundtrips, and 10% fly at least five. Usually, discussions of elite versus regular people do not define the elite as the top half; even the top 10% is rare, in these times of rhetoric about the top 1% and 0.1%. When Larry Summers called for infrastructure investment into airport transit, he said it would improve social equity because what he considered the elite had private jets. But what’s actually happening is not necessarily about the top 0.1% or 1% or even 5% directing government spending their way. It may be so; certainly politicians travel far more than the average person, and so do very rich donors. But broad segments of the middle class fly regularly. The average income of regular fliers is presumably considerably higher than that of people who do not fly, but not to the same extent as the picture drawn by political populists. None of this makes airport transit a great idea. Of course some projects are good, but the basic picture is still one in which per rider spending on airport connectors is persistently higher than on other projects, by a large factor. In New York, the JFK AirTrain cost about$2 billion in today’s money and carries 6.4 million riders a year, which would correspond to 21,000 weekday riders if it had the same annual-to-weekday passenger ratio as regular transit, 300 (it has a much higher ratio, since air travel does not dip on weekends the way commuter travel does). This is around $100,000 per rider, which contrasts with$20,000 for Second Avenue Subway Phase 1 if ridership projections hold. Earlier this year, the de Blasio administration proposed a developed-oriented waterfront light rail, projected to cost $1.7 billion and get 16 million riders a year, which corresponds to about$32,000 per daily rider; a subsequent estimate pegs it at $2.5 billion, or$47,000 per rider, still half as high as how much the AirTrain cost.

However, what I propose is that the high cost of airport connectors is not because the elite spends money on itself. Rather, it’s because many ordinary middle-class people fly a few times a year and wish for better airport transit, without thinking very hard about the costs and benefits. An airport connector appeals to a very wide section of the population, and may be very cheap if we divide the cost not by the number of daily users but by the number of unique annual users. Hence, it’s easier for politicians to support it, in a way they wouldn’t support an excessively costly subway line connecting a few residential neighborhoods to the city.

It’s a political failure, but not one that can be resolved by more democratic means. The conventional analysis that the root cause is excessive attention to elite concerns implies that if spending were decided in more democratic ways, it would be directed toward other causes. But if the hypothesis I’m putting forth is right, then democracy would not really resolve this, since the number of people who would benefit from an airport connector, if only shallowly, is large. A rigorous regime of cost-benefit analyses, including publicized estimates of cost per rider and the opportunity cost, would be required.

Following plans by the government of Norway to ban cars fueled by petrol or diesel by 2025, several other countries in Europe are formulating similar programs to phase out fuel-powered transportation. Moreover, sources close to the European Parliament say that once multiple member states pass such a ban as is expected later this year, the European Union will attempt to enforce these rules throughout its territory.

In Sweden, the office of Åsa Romson, minister for the environment and co-spokesperson for the Green Party, released a statement saying that a ban on the internal combustion engine is a necessary step to reduce pollution and carbon emissions. In Sweden, only about 3% of electricity production comes from fossil fuels, and plans made by the Persson cabinet in 2005, Making Sweden an Oil-Free Society, already call for a phaseout of the use of oil for heating. The Löfven cabinet has nowhere else to cut in its program to make Sweden a carbon-neutral society by 2050. The Social Democrats-Green minority government is expected to work with the more moderate parties in the opposition Alliance; the Centre Party has already endorsed the move, but the Liberals have yet to make a statement.

In France and Germany, the ban is expected to be far more contentious. Auto manufacturers in both countries have condemned the moves by their respective governments to ban the internal combustion engine, saying that it would make the economy less competitive. European automakers have lagged behind Japanese and American ones in both hybrid and all-electric car technology, as conventional European petrol and diesel cars already have high fuel economy. In response to so-called range anxiety, in which an electric car’s limited range may leave the driver stranded on the motorway, the Hollande administration is expected to pair the proposed phaseout with national investment into charging stations as well as additional investment into TGV lines, to make it easier to travel long distances in France without a car.

Demands by BMW and Volkswagen for Germany to commit to spending money on R&D for improved battery range and charging and battery swap stations on the highway network have run into budgetary problems. While Chancellor Angela Merkel is reported to be interested in implementing a phaseout, in order to attract Green support into a possible future grand coalition and reduce EU dependence on oil imports from Russia, Finance Minister Wolfgang Schäuble has openly rejected any package that would raise the budget deficit, and the allied Christian Social Union has rejected the proposed ban on principle. Opposition from far-right populist parties, including the Alliance for Germany (AfD) and France’s National Front (FN), is likely to be significant, and sources close to Hollande and Merkel say that both have ruled out tax increases to pay for the program.

In France the calls for a phaseout of the internal combustion engine are especially loud in the Paris region, where high levels of particulate pollution from diesel vehicles led to recent restrictions on car use. The mayor of Paris, the Socialist Anne Hidalgo, previously proposed to ban diesel vehicles from the city entirely, and has endorsed the state’s plans to phase out fuel-powered vehicles, adding that given Paris’s pollution crisis, a local ban on diesel vehicles should be implemented immediately. The president of the regional council, Valérie Pécresse of the Republicans (LR), is said to support the phaseout as well, and to push LR behind the scenes not to oppose it. Conversely, opposition from FN is especially acute. The party leader, Marine le Pen, quipped that France would not need any additional reductions in greenhouse gas emissions if it had not taken in non-European immigrants since the 1960s, and noted that the immigrants are especially likely to settle in Paris, where the problems are the most acute.

Elsewhere in Europe, Belgium, Switzerland, and the Netherlands are said to be considering a phaseout by 2030. Within Belgium, Saudi support of mosques preaching radical interpretations of Islam is said to have influenced the country’s liberal parties, the Francophone Reformist Movement (MR) and the Flemish Liberals and Democrats (VLD), to support a phaseout. However, the Flemish nationalist parties remain opposed, and the New Flemish Alliance (N-VA) issued a statement saying that this solution may work within Brussels but is inappropriate for Flanders. In contrast, the Netherlands is expected to pass the phaseout without any political problems. In Switzerland, a referendum is planned for next year, and early polling suggests that it is supported by 55-60% of the population.

Governments outside Europe are said to be watching the development closely, especially in France and Germany, which are perceived as more reliable bellwethers of European opinion than Sweden. In Japan, home to the world’s top-selling electric car, the Nissan Leaf, political support for a phaseout appears high. Prime Minister Shinzo Abe has called climate change a “defining issue of our time,” and is working on a national infrastructure plan. Sources close to Abe say it will pair subsidies for so-called city cars, short-range electric vehicles, with investments into the country’s rail network outside major metropolitan areas, to make it easier for people living outside the biggest cities to travel on public transport.

In the US, both the Obama administration and Hillary Clinton’s presidential campaign refused to comment, saying that it is an internal European affair. However, sources close to the administration say that it is already planning to use the Environmental Protection Agency’s executive power to restrict the sale of new fuel-powered cars to emergency needs. The sources speculate that an executive order is planned for shortly after the presidential election this November, provided Clinton wins, in order to avoid creating backlash among key swing constituencies, including the automakers and the exurban lower middle class. Donald Trump’s presidential campaign’s response is unprintable.

# Train Operator Labor Efficiency

Last summer, I brought up a metric of railroad labor efficiency: annual revenue hours per train driver. Higher numbers mean that train drivers spend a larger proportion of their work schedule driving a revenue train rather than deadheading, driving a non-revenue train, or waiting for their next assignment. As an example, I am told on social media that the LIRR schedules generous crew turnaround times, because the trains aren’t reliably punctual, and by union rules, train drivers get overtime if because their train is late they miss the next shift. Of note, all countries in this post have roughly the same average working hours (and the US has by a small margin the highest), except for France, which means that significant differences in revenue hours per driver are about efficiency rather than overall working hours.

I want to clarify that even when union work rules reduce productivity, low productivity does not equal laziness. Low-frequency lines require longer turnaround times, unless they’re extremely punctual. Peakier lines require more use of split shifts, which require giving workers more time to commute in and out.

The database is smaller than in my posts about construction costs, because it is much harder to find information about how many train operators a subway system or commuter railroad employs than to find information about construction costs. It is often also nontrivial to find information about revenue hours, but those can be estimated from schedules given enough grunt work.

In Helsinki, there is a single subway trunk splitting into two branches, each running one train every 10 minutes all day, every day: see schedules here and here. This works out to 65,000 train-hours a year. There are 75 train drivers according to a 2010 factsheet. 65,000/75 = 867 hours per driver. This is the highest number on this list, and of note, this is on a system without any supplemental peak service, allowing relatively painless scheduling.

In London, unlike in North America, the statistics are reported in train-km and not car-km. There are 76.2 million train-km a year, and average train speed is 33 km/h, according to a TfL factsheet; see also PDF-p. 7 of the 2013-4 annual report. In 2012, the last year for which there is actual rather than predicted data, there were 3,193 train drivers, and according to the annual report there were 76 million train-km. 76,000,000/33 = 2,300,000 revenue-hours; 2,300,000/3,193 = 721 hours per driver.

In Tokyo, there used to be publicly available information about the number of employees in each category, at least on Toei, the smaller and less efficient of the city’s two subway systems. As of about 2011, Toei had 700 hours per driver: from Hyperdia‘s schedules, I computed about 390,000 revenue train-hours per year, and as I recall there were 560 drivers, excluding conductors (half of Toei’s lines have conductors, half don’t).

In New York, we can get revenue car-hour statistics from the National Transit Database, which is current as of 2013; the subway is on PDF-p. 13, Metro-North is on PDF-p. 15, and the LIRR is on PDF-p. 18. We can also get payroll numbers from SeeThroughNY. The subway gets 19,000,000 revenue hours per year; most trains have ten cars, but a substantial minority have eight, and a smaller minority have eleven, so figure 2,000,000 train-hours. There were 3,221 train operators on revenue vehicles in 2013, and another 373 at yards. This is 556 hours per driver if the comparable international figure is all drivers, or 621 if it is just revenue vehicle drivers. The LIRR gets 2,100,000 annual revenue car-hours, and usually runs trains of 8 to 12 cars; figure around 210,000. There were 467 engineers on the LIRR in 2013; this is 450 hours per driver. Metro-North gets 1,950,000 annual revenue car-hours, and usually runs 8-car trains; figure about 240,000. It had 413 locomotive engineers in 2013; this is 591 hours per driver.

In Paris, the RER A has 523 train drivers (“conducteurs”). The linked article attacks the short working hours, on average just 2:50 per workday. The timetable is complex, but after adding the travel time for each train, I arrived at a figure of 230,000 train-hours a year. 230,000/523 = 440 hours per driver. There’s a fudge factor, in that the article is from 2009 whereas the timetable is current, but the RER A is at capacity, so it’s unlikely there have been large changes. Note also that in France, workers get six weeks of paid vacation a year, and a full-time workweek is 35 hours rather than 40; adjusting for national working hours makes this equivalent to 534 hours in the US, about the same as the New York subway.

In New York, the de Blasio administration has been spending considerable political capital pushing for a 2.5 billion light rail line connecting Astoria and the Brooklyn waterfront south to Sunset Park. There has been a lot of criticism from good transit advocates about implementation – namely, it’s unclear there will be free transfers to the subway and buses, in order to avoid having to share turf with the state-owned MTA – but also of the basic concept, which is not the biggest transit priority in the region, or for matter the twentieth. In comments and on social media, I’ve seen a few wrong arguments made in support of waterfront light rail and similar bad investments over and over, and I’d like to go in some detail into where cities should and should not build such lines. The principles below are based on various oppositions: first world versus third world, fast versus slow growth, subway versus no subway. I think a good meta-principle is that if the presence of a certain factor is an argument in favor of a specific solution, then its absence should be an argument against that solution. For instance, if high wages are an argument in favor of rail and against bus rapid transit, then low wages should be an argument in favor of bus rapid transit; this principle makes me wonder what Addis Ababa was thinking when it built light rail instead of BRT, while at the same time thinking very little of American cities that make the decision that Addis Ababa should have made. The upshot of the meta-principle is that many of the guidelines that work in New York could work in very different cities, in reverse. 1. New York is a mature first-world city with low population growth; it should build transit exclusively or almost exclusively based on current population and transportation patterns, and not attempt to engage in development-oriented transit. The upzoning the city engages in is too small compared to current population, and cannot justify anything of the magnitude of Vancouver’s Expo Line, which was built simultaneously with Metrotown and the New Westminster offices around the train stations. And even Vancouver cannot reasonably expect the growth rates of various third-world cities with annual population growth rates in the vicinity of 5% and even higher per capita income growth rates. 2. Rail bias is approximately the same on all routes. Routes with many turns and narrow roads have unusually slow buses, but they’ll also have unusually slow surface rail. Rapid transit does have the ability to avoid the extra traffic jams coming from such alignments, and this is especially important in cities where the main street is not the same as the nearby wide boulevard, but this is not what’s under discussion in New York. Yes, de Blasio’s proposed light rail line would get more riders than the buses on segments of the route in question are getting now; the same would be true of any number of light rail routes paralleling the busiest buses in the city. 3. In a city with a subway, the best light rail routes are the ones that don’t make sense as subway extensions. Of the three busiest buses in New York, two make sense as subway lines, so there’s no point building light rail and only later a subway: the M15, on First and Second Avenues, and the B46, on Utica. In contrast, the third route, the Bx12 on Fordham, is crosstown, and cannot reasonably be an extension of any subway line, so it would be a strong light rail corridor. The same can be said of Main Street in Queens, between Flushing and Jamaica; and 14th and 86th Streets in Manhattan, where the M14 and M86 are the busiest surface routes in the US in terms of riders per kilometer, well ahead of the Boston Green Line (they both have about 8,000, and the Green Line 6,000). Of note, 14th Street already hosts the L, but a branch going on Avenue D is far from the subway, and the street is so well-trafficked that despite slower-than-walking bus speeds, that arguably light rail makes sense there even with the subway. 4. As soon as a project is judged as not a top priority, it’s best to think of how useful it is once the top priorities are built. In the case of New York, let us zoom in on Brooklyn’s top two circumferential buses, the B4 B6 and B35. Triboro RX is a higher priority than turning these routes into light rail, and once it’s in place, how much demand is there really going to be for them? It would be faster to take the subway and connect to Triboro, except at very short distances, where speeding up surface traffic is less useful. In New York, excluding the somewhat special cases of 14th and 86th Streets, I’d say there are three light rail networks that make sense: one in the Bronx, one in Brooklyn, and one in Queens. The Bronx network involves taking the borough’s most frequent buses and turning them into light rail routes: the Bx12 on Fordham as noted above, but also the Bx1/2 on Grand Concourse (like 14th Street, hosting both a subway and a very busy bus route), the Bx19 on Southern and 145th, the Bx15 on Third, and a route on Tremont combining the Bx36 and the Bx40/42. These routes roughly form a grid, each has at least 30,000 weekday riders, and none is SBS except the Bx12. In this case, light rail should really be thought of as the next step after publishing a frequent grid map based on these routes and equipping the entire city bus fleet with off-board fare collection. In Queens, there’s less room for a grid – the borough has street grids, but it really is based on several old centers, with major roads connecting them. The strongest routes are the ones that cannot reasonably be subway extensions, because they’re too circumferential; in turn, the strongest subway extension, i.e. Northern, is not a major bus route, because it’s close enough to the Queens Boulevard subway that people instead take the subway, which is overcrowded. Of the strong surface transit routes, the corridor with the highest ridership takes in several bus routes between Flushing and Jamaica; Main Street is the most important route, but potentially there’s room both there and on the second route, Kissena-Parsons. Other potential light rail routes radiate from Flushing and Jamaica, in directions not well-served by the subway and the LIRR, or even west on Queens Boulevard to help serve the gap in subway coverage between the 7 and the Queens Boulevard Line and relieve the subway lines. Brooklyn is the most interesting. The main missing pieces in subway coverage in Brooklyn are good subway extensions: Triboro, Utica, Nostrand. With those in place, the only real gaps are Flatbush, and some route serving Red Hook. Possibly service to the Navy Yard may be desirable, but the area is not very well-developed right now, and the buses serving it have low ridership. Those are two or three routes radiating out of the same center in Downtown Brooklyn, which makes it tempting to not only build light rail on them, but also send it over the Brooklyn Bridge to City Hall. This would be like the subway-surface lines in Boston and San Francisco, where one underground trunk splits into several at-grade branches, except that in this case the trunk would be elevated rather than underground. It’s not worth building by itself, but the possibility of leveraging Brooklyn Bridge lanes for several light rail lines may make the ridership per unit of cost pencil out. The common factor to all of these possibilities is that they are not meant for signature development areas that the city is targeting. Maybe there’s some new development there, but the focus is on improving public transit services to existing residents, who either are riding very slow buses or have given up on public transit because of the inconvenience. It can be marketed as an improvement in transit, but cannot really be sold as part of a plan to revitalize the Brooklyn waterfront. It’s about day-to-day governing, whereas the administration is interested in urban renewal schemes, which are rarely good transit. # Why Costs Matter Stockholm is currently expanding its transit system, with about 19 kilometers of subway extension, and another 6 kilometers of a commuter rail tunnel taking regional traffic off the at-capacity mainline. The subway extension, excluding rolling stock acquisition, costs about2.1 billion, and the commuter rail extension $1.8 billion. The US is currently building five subways: Second Avenue Subway Phase 1 (2.8 km,$4.6 billion), East Side Access (2.2 km, $10 billion), the first phase of the Wilshire subway (6.3 km,$2.8 billion), the Regional Connector (3.1 km, $1.4 billion), U-Link (5 km,$1.8 billion). Two more projects are partially underground: the Crenshaw/LAX Line, a total of 13.7 km of which 4.7 are underground, at a total cost of $2.1 billion, and the Warm Springs BART extension, a total of 8.6 km of which 1.6 are underground, at a total cost of$900 million. (Update 2/1: the Central Subway is $1.6 billion for 2.8 km. Thanks to Joel for pointing out that I forgot about it.) The first observation is that Sweden has just 700 meters 3.5 km of subway under construction less than the US under construction, despite a vast gap in not only population but also current transit usage. Stockholm may have twice the per capita rail ridership of New York, but it’s still a small city, the size of Indianapolis, Baltimore, Portland, or Charlotte; 450 million annual rail trips is impressive for a city of its size, but the US combined has more than 3 billion. This relates to differences in costs: the amount of money Sweden is putting into heavy rail infrastructure is$3.9 billion, vs. $23.6 billion$25.2 billion among the seven eight US projects, which approaches the ratio of national subway and commuter rail ridership levels.

The second observation is that the US spending is not really proportional to current rail ridership. Two thirds of the spending is in New York, as is two thirds of US rail ridership, but nearly everything else is in Los Angeles, which takes in a majority of current subway construction route-length. Los Angeles is a progressive city and wants better public transit, but the same is true in many of the six major US transit cities – New York, Washington, San Francisco, Chicago, Boston, and Philadelphia. And yet, of those six, only New York and San Francisco are building urban subways (BART’s one mile of tunnel is in a suburb, under a park).

The difference is that Los Angeles builds subways at $400-450 million per km in the city core (less in future phases of the Wilshire subway), whereas in most of the US, lines are either more expensive or more peripheral. Boston, the Bay Area, and Washington are expanding their rapid transit networks, but largely above-ground or in a trench, and only outside the core. Boston’s Green Line Extension is in a trench, but has had major budget overruns and is currently on the high side for a full subway ($3 billion for 6.9 km), and the MBTA is even putting canceling the project on the table due to the cost. Washington’s Silver Line Phase 2 is 18.5 km and $2.7 billion, in a highway median through the Northern Virginia suburbs. BART’s Warm Springs extension is about$100 million per km, which is not outrageously high, but the next extension of the line south, to Berryessa, is $2.3 billion for 16 km, all above ground. Let us now stay on the North American West Coast, but go north, to Vancouver. Vancouver’s construction costs are reasonable: the cost projections for the Broadway subway (C$2.7 billion ex-vehicles, PDF-p. 95) are acceptable relative to route-length (12.4 km, PDF-p. 62) and very good relative to projected ridership (320,000 per weekday, PDF-p. 168). Judging by the costs of the Evergreen and Canada Lines, and the ridership evolution of the Canada Line, these projections seem realistic. And yet, in a May 2015 referendum about funding half the line as well as many other transit projects, 62% of the region’s voters, including a bare majority in Vancouver proper, voted no.

The referendum’s result was not a shock. In the few months before the vote, the polls predicted a large, growing no vote. Already in February, the Tyee was already comparing Vancouver negatively with Stockholm, and noting that TransLink’s regional governance structure was unusual, saying the referendum was designed to fail. This is not 100% accurate: in 2014, polls were giving the yes side a majority. The deterioration began around the end of 2014 or beginning of 2015: from 52-39 in December to 46-42 in January, to 27-61 in March. The top reason cited by no voters was that they didn’t trust TransLink to spend the money well.

This cannot be divorced from Vancouver’s Compass Card debacle: plans to replace paper tickets and SkyTrain’s proof-of-payment system with a regionwide smartcard, called Compass, and faregates on SkyTrain, were delayed and run over budget. The faregates aren’t even saving money, since TransLink has to pay an operating fee to vendor Cubic that’s higher than the estimated savings from reduced fare evasion. The height of the scandal was in 2014, but it exploded in early 2015, when TransLink replaced its manager amidst growing criticism. The referendum would probably have been a success a year earlier; it was scheduled in what turned out to be a bad period for TransLink.

The importance of the Vancouver example is that construction costs are not everything. Transit agencies need to get a lot of things right, and in some cases, the effects are quite random. (Los Angeles, too, had a difficult rollout of a Cubic-run faregate system.) The three key principles here are, then:

1. Absolute costs matter. They may not directly affect people’s perceptions of whether construction is too expensive. But when legislators have to find money for a new public transit project, they have some intuitive idea of its benefits, give or take a factor of perhaps 2. Gateway is being funded, even though with the latest cost overrun (to $23.9 billion) the benefit-cost ratio in my estimation is about 1/3, but this involved extensive lobbying by Amtrak, lying both to Congress and to itself that it is a necessary component of high-speed rail. Ordinary subways do not have the luxury of benefiting from agency imperialism the way the Gateway project did; if they’re too expensive, they’re at risk of cancellation. 2. Averaged across cities and a number of years of construction, cities and countries with lower construction costs will build more public transit. We see this in the US vs. Sweden. Of course, there are periods of more construction, such as now, and periods of less, such as around 2000, but this affects both countries right now. 3. Variations from the average are often about other issues of competence – in Vancouver’s case, the failure of the faregates and the delayed Compass rollout. Political causes are less important: Vancouver’s business community opposed the transit referendum and organized against it, but it’s telling that it did so and succeeded, whereas business communities in cities with more popular transit authorities support additional construction. In a post from 2011, Yonah Freemark argued that California HSR’s projected cost’s upper end was just 0.18% of the projected GDP of California over a 20-year construction period. The implication: the cost of high-speed rail (and public transit in general) is small relative to the ability of the economy to pay. This must be paired with the sobering observation that the benefits of public transit are similarly small, or at most of the same order of magnitude. New York’s survived decades without Second Avenue Subway. It’s a good project to have, provided the costs are commensurate with the benefits, but without cost containment, phase 2 is probably too expensive, and phases 3 and 4 almost certainly. What’s more, the people funding such projects – the politicians, the voters, even the community organizations – consider them nice-to-haves. The US has no formal mechanism of estimating benefit-cost ratios, and a lot of local political dysfunction, and this can distort the funding, to the point that Gateway is being funded even though at this cost it shouldn’t. But, first, even a factor of 3 distortion is unusual, and second, on average, these distortions cancel out. Democrats and Republicans shouldn’t plan on controlling either Congress or the White House more than about half the time, in the long run, and transit activists shouldn’t plan on political dysfunction persistently working in their favor. The only route forward is to improve the benefit-cost ratio. On the benefit side, this means aggressive upzoning around subway stations, probably the biggest lacuna in Los Angeles’s transit construction program. But in New York, and even in the next five transit cities in the US, this is not the main problem: population density on many corridors is sufficient by the standards of such European transit cities as Stockholm, Berlin, London, and Munich, none of which is extraordinarily dense like Paris. No: the main problem in most big US cities is costs, and almost only costs. Operating costs, to some extent, but mainly capital construction costs. Congress and the affected states apparently have enough political will to build a 5-km tunnel for$20 billion going on $24 billion; if this system could be built for$15 billion, they’d jump at the opportunity to take credit. The US already has the will to spend reasonable amounts of money on public transit. The difference is that its $24 billion$25 billion of spending on subways buys 26 km 28.5 km of subway and 16 km of a mix of light rail and el, where it could be buying 120 km 125 km of subway. Work out where you’d build the extra 94 km 96.5 km and ask yourself if ignoring costs is such a good idea for transit activists.

# Modeling Anchoring

Jarrett Walker has repeatedly called transit agencies and city zoning commissions to engage in anchoring: this means designing the city so that transit routes connect two dense centers, with less intense activity between them. For example, he gives Vancouver’s core east-west buses, which connect UBC with dense transit-oriented development on the Expo Line, with some extra activity at the Canada Line and less intense development in between; Vancouver has adopted his ideas, as seen on PDF-page 15 of a network design primer by Translink. In 2013, I criticized this in two posts, making an empirical argument comparing Vancouver’s east-west buses with its north-south buses, which are not so anchored. Jarrett considers the idea that anchoring is more efficient to be a geometric fact, and compared my empirical argument to trying to empirically compute the decimal expansion pi to be something other than 3.1415629… I promised that I would explain my criticism in more formal mathematical terms. Somewhat belatedly, I would like to explain.

First, as a general note, mathematics proves theorems about mathematics, and not about the world. My papers, and those of the other people in the field, have proven results about mathematical structures. For example, we can prove that an equation has solutions, or does not have any solutions. As soon as we try to talk about the real world, we stop doing pure math, and begin doing modeling. In some cases, the models use advanced math, and not just experiments: for example, superstring theory involves research-level math, with theorems of similar complexity to those of pure math. In other cases, the models use simpler math, and the chief difficulty is in empirical calibration: for example, transit ridership models involve relatively simple formulas (for example, the transfer penalty is a pair of numbers, as I explain here), but figuring out the numbers takes a lot of work.

With that in mind, let us model anchoring. Let us also be completely explicit about all the assumptions in our model. The city we will build will be much simpler than a real city, but it will still contain residences, jobs, and commuters. We will not deal with transfers; neither does the mental model Jarrett and TransLink use in arguing for anchoring (see PDF-p. 15 in the primer above again to see the thinking). For us, the city consists of a single line, going from west to east. The west is labeled 0, the east is labeled 1, and everything in between is labeled by numbers between 0 and 1. The city’s total population density is 1: this means that when we graph population density on the y-axis in terms of location on the x-axis, the total area under the curve is 1. Don’t worry too much about scaling – the units are all relative anyway.

Let us now graph three possible distributions of population density: uniform (A), center-dominant (B), and anchored (C).

Let us make one further assumption, for now: the distributions of residences and jobs are the same, and independent. In city (A), this means that jobs are uniformly distributed from 0 to 1, like residences, and a person who lives at any point x is equally likely to work at any point from 0 to 1, and is no more likely to work near x than anyone else. In city (B), this means that people are most likely to work at point 0.5, both if they live there and if they live near 0 or 1; in city (C), this means that people are most likely to work at 0 or 1, and that people who live at 0 are equally likely to work near 0 and near 1.

Finally, let us assume that there is no modal splitting and no induced demand: every employed person in the city rides the bus, exactly once a day in each direction, once going to work and once going back home, regardless of where they live and work. Nor do people shift their choice of when to work based on the network: everyone goes to work in the morning peak and comes back in the afternoon peak.

With these assumptions in mind, let us compute how crowded the buses will be. Because all three cities are symmetric, I am only going to show morning peak buses, and only in the eastbound direction. I will derive an exact formula in city (A), and simply state what the formulas are in the other two cities.

In city (A), at point x, the number of people who ride the eastbound morning buses equals the number of people who live to the west of x and work to the right of x. Because the population and job distributions are uniform, the proportion of people who live west of x is x, and the proportion of people who work east of x is 1-x. The population and job distributions are assumed independent, so the total crowding is x(1-x). Don’t worry too much about scaling again – it’s in relative units, where 1 means every single person in the city is riding the bus in that direction at that time. The formula y = x(1-x) has a peak when x = 0.5, and then y = 0.25. In cities (B) and (C), the formulas are:

(B): $y = \begin{cases}2x^2(1 - 2x^2) & \mbox{ if } x \leq 1/2\\ 2(1-x)^2(1 - 2(1-x)^2) & \mbox{ if } x > 1/2\end{cases}$

(C): $y = \begin{cases}(2x-2x^2)(1 - 2x + 2x^2) & \mbox{ if } x \leq 1/2\\ (2(1-x)-2(1-x)^2)(1 - 2(1-x) + 2(1-x)^2) & \mbox{ if } x > 1/2\end{cases}$

Here are their graphs:

Now, city B’s buses are almost completely empty when x < 0.25 or x > 0.75, and city C’s buses fill up faster than city A’s, so in that sense, the anchored city has more uniform bus crowding. But the point is that at equal total population and equal total transit usage, all three cities produce the exact same peak crowding: at the midpoint of the population distribution, which in our three cases is always x = 0.5, exactly a quarter of the employed population lives to the west and works to the east, and will pass through this point on public transit. Anchoring just makes the peak last longer, since people work farther from where they live and travel longer to get there. In a limiting case, in which the population density at 0 and 1 is infinite, with half the population living at 0 and half at 1, we will still get the exact same peak crowding, but it will last the entire way from 0 to 1, rather than just in the middle.

Note that there is no way to play with the population distribution to produce any different peak. As soon as we assume that jobs and residences are distributed identically, and the mode share is 100%, we will get a quarter of the population taking transit through the midpoint of the distribution.

If anything, the most efficient of the three distributions is B. This is because there’s so little ridership at the ends that it’s possible to run transit at lower frequency at the ends, overlaying a route that runs the entire way from 0 to 1 to a short-turn route from 0.25 to 0.75. Of course, cutting frequency makes service worse, but at the peak, the base frequency is sufficient. Imagine a 10-minute bus going all the way, with short-turning overlays beefing frequency to 5 minutes in the middle half. Since the same resources can more easily be distributed to providing more service in the center, city B can provide more service through the peak crowding point at the same cost, so it will actually be less crowded. This is the exact opposite of what TransLink claims, which is that city B would be overcrowded in the middle whereas city C would have full but not overcrowded buses the entire way (again, PDF-p. 15 of the primer).

In my empirical critique of anchoring, I noted that the unanchored routes actually perform better than the anchored ones in Vancouver, in the sense that they cost less per rider but also are less crowded at the peak, thanks to higher turnover. This is not an observation of the model. I will note that the differences in cost per rider are not large. The concept of turnover is not really within the model’s scope – the empirical claim is that the land use on the unanchored routes lends itself to short trips throughout the day, whereas on the anchored ones it lends itself to peak-only work trips, which produce more crowding for the same total number of riders. In my model, I’m explicitly ignoring the effect of land use on trips: there are no induced trips, just work trips at set times, with 100% mode share.

Let us now drop the assumption that jobs and residences are identically distributed. Realistically, cities have residential and commercial areas, and the model should be able to account for this. As one might expect, separation of residential and commercial uses makes the system more crowded, because travel is no longer symmetric. In fact, whereas under the assumption the peak crowding is always exactly a quarter of the population, if we drop the assumption the peak crowding is at a minimum a quarter, but can grow up to the entire population.

Consider the following cities, (D), (E), and (F). I am going to choose units so that the total residential density is 1/2 and so is the total job density, so combined they equal 1. City (D) has a CBD on one side and residences on the other, city (E) has a CBD in the center and residences on both sides, and city (F) is partially mixed-use, with a CBD in the center and residences both in the center and outside of it. Residences are in white, jobs are in dark gray, and the overlap between residences and jobs in city (F) is in light gray.

We again measure crowding on eastbound morning transit. We need to do some rescaling here, again letting 1 represent all workers in the city passing through the same point in the same direction. Without computing, we can tell that in city (D), at the point where the residential area meets the commercial area, which in this case is x = 0.75, the crowding level is 1: everyone lives to the west of this point and works to its east and must commute past it. Westbound morning traffic, in contrast, is zero. City (E) is symmetric, with peak crowding at 0.5, at the entry to the CBD from the west, in this case x = 0.375. City (F) has crowding linearly growing to 0.375 at the entry to the CBD, and then decreasing as passengers start to get off. The formula for eastbound crowding is,

(F): $y = \begin{cases}x & \mbox{ if } x < 3/8\\ x(5/2 - 4x) & \mbox{ if } 3/8 \leq x \leq 5/8\\ 0 & \mbox{ if } x > 5/8\end{cases}$

In city (F), the quarter of the population that lives in the CBD simply does not count for transit crowding. The reason is that, with the CBD occupying the central quarter of the city, at any point from x = 0.375 east, there are more people who live to the west of the CBD getting off than people living within the CBD getting on. This observation remains true down to when (for a symmetric city) a third of the population lives inside the CBD.

In city (B), it’s possible to use the fact that transit runs empty near the edges to run less service near the edges than in the center. Unfortunately, it is not possible to use the same trick in cities (E) and (F), not with conventional urban transit. The eastbound morning service is empty east of the CBD, but the westbound morning service fills up; east of the CBD, the westbound service is empty and the eastbound service fills up. If service has to be symmetric, for example if buses and trains run back and forth and make many trips during a single peak period, then it is not possible to short-turn eastbound service at the eastern edge of the CBD. In contrast, if it is possible to park service in the center, then it is possible to short-turn service and economize: examples include highway capacity for cars, since bridges can have peak-direction lanes, but also some peaky commuter buses and trains, which make a single trip into the CBD per vehicle in the morning, park there, and then make a single trip back in the afternoon. Transit cities relies on services that go back and forth rather than parking in the CBD, so such economies do not work well for them.

A corollary of the last observation is that mixed uses are better for transit than for cars. Cars can park in the CBD, so for them, it’s fine if the travel demand graph looks like that of city (E). Roads and bridges are designed to be narrower in the outskirts of the region and wider near the CBD, and peak-direction lanes can ensure efficient utilization of capacity. In contrast, buses and rapid transit trains have to circulate; to achieve comparable peak crowding, city (E) requires twice as much service as perfect mixed-use cities.

The upshot of this model is that the land use that best supports efficient use of public transit is mixed use. Since all rich cities have CBDs, they should work on encouraging more residential land uses in the center and more commercial uses outside the center, and not worry about the underlying distribution of combined residential and job density. Since CBDs are usually almost exclusively commercial, any additional people living in the center will not add to transit crowding, even as they ride transit to work and pay fares. In contrast, anchoring does not have any effect on peak crowding, and on the margins makes it worse in the sense that the maximum crowding level lasts longer. This implies that the current planning strategy in Vancouver should be changed from encouraging anchoring to fill trains and buses for longer to encouraging more residential growth Downtown and in other commercial centers and more commercial growth at suitable nodes outside the center.