Buses Versus Trams: Low-Floor Boarding

For years, Jarrett Walker has been making the point that streetcars do not provide much transportation value over buses. They have higher capacity, because trams can run longer vehicles, but on a medium-ridership bus line without capacity constraints, this is not relevant. As I note in comments, tramways can use rail signaling to get marginal speed advantages, but it’s not a big advantage. They also have slightly lower minimum headways – a single bus route running more often than every 3 minutes will hopelessly bunch, whereas tramways seem capable of higher frequency – but this is again a matter of capacity. And yet, there is an observed rail bias, even when other factors are kept the same: a Transportation Research Bureau report by Edson Tennyson concludes it is 34-43%, using evidence from North American cities in the four decades after WW2. In this post, I would like to propose one mechanism that may produce rail bias even when speed, capacity, and frequency are unchanged.

Low-floor vehicles make it easier to board from raised curbs. Passengers do not need to climb steps as they do on older buses and streetcars, but can walk straight to the vehicle. This speeds up boarding and improves the passenger experience: see p. 14 of a presentation about commuter rail level boarding, p. 64 of a book about low-floor light rail, and a study about bus dwell times in Portland. It’s especially useful for passengers in wheelchairs: as the Portland bus reference notes, the difference between low- and high-floor buses’ dwell times is especially noticeable when there are wheelchair lifts, because operating a wheelchair lift on a low-floor bus is much faster than on a high-floor bus. Low-floor vehicles’ ability to not lose too much time every time a disabled passenger boards or disembarks improves reliability, which in turns allows schedules to be less padded, improving trip times even when no passenger in a wheelchair uses the route.

While high-floor buses and high-floor trains serving low platforms are similar in requiring passengers to climb multiple steps, low-floor buses and trains with level boarding (regardless of whether high or low) are different. Trains run on guideways; they can have the vehicle’s edge exactly level with the platform edge, with narrow horizontal gap. My attempt to measure this on SkyTrain in Vancouver yielded a horizontal gap of about 5 cm, and a vertical gap of perhaps 2 cm; with such gaps, passengers in wheelchairs can board unaided. While SkyTrain is automated rapid transit rather than light rail, nothing about its technology makes the rail-platform gap easier to resolve than on other rail lines.

In contrast, low-floor buses do not have true level boarding. The bus floor is still raised from the curb somewhat, so modern low-floor buses typically kneel, increasing dwell time by a few seconds per stop, to reduce the platform gap. While it’s possible to raise the curbs as at light rail stops, the buses are still buses, and cannot align themselves to be as close to the platform as trains are: without rails, they sway from side to side, so a safety margin is required from the platform edge. As a result, passengers in wheelchairs cannot board unaided without a retractable ramp, which adds considerable dwell time. On board the bus, the more sudden acceleration also requires the wheelchair to be strapped, adding dwell time even further.

Because there is no way to prevent a bus from incurring schedule risk if there’s a passenger in a wheelchair, bus schedules are inherently more vulnerable than train schedules. While few transit passengers are in wheelchairs, passengers who have luggage, walkers, or strollers can get on and off much faster when there’s perfect level boarding, and are slowed by the need to navigate steps or a wide vehicle-platform gap; the schedule will have to take this into account. Low-floor buses reduce this problem, but do not eliminate it.

The limiting factor to bus frequency is not stopping distances, unlike the case of trains. Instead, it is bunching: at very high frequency, small variations in boarding time compound, as fuller buses are harder to board. Soon enough a slightly delayed bus becomes even more delayed as passengers take more time to board, until it bunches with the bus behind it. This effect can be reduced with off-board fare collection, but when the bus is crowded, the combination of narrow passageways and a significant platform gap means that boarding time is nontrivial no matter what.This effect means that all else being equal, a low-floor tramway will be faster and more reliable than a low-floor bus. In practice, all else is not equal, and in particular, in mixed traffic, the bus’s ability to get around obstacles will make it faster. But with well-enforced dedicated lanes, tramways are capable of running reliably with less schedule padding than buses. A familiar experience to North American bus riders – sitting for several minutes as a passenger in a wheelchair boards, and maneuvers awkwardly through the narrow spaces to where the bus driver will strap in the chair – is not an issue on any train with level boarding.

Mixing Circumferential and Radial Transit in the Other Direction

Two years ago, I wrote a post criticizing subway lines that mix radial and circumferential elements. These lines, for examples Shanghai Metro Lines 3 and 6 and New York’s G train before 2001, contain long radial segments, going from an outlying neighborhood toward city center, but then switch to circumferential mode, avoiding city center and instead serving secondary nodes. Such lines do not get high ridership, because they fail at either radial or circumferential transit. Recently, I was challenged in comments about my support for a mixed line that goes in the other direction: circumferential on the outside, radial on the inside. I would like to talk more about such lines.

Consider the following diagram of a subway system:

subwaydiagram

The city is shown in light gray, with its center in dark gray. There are five subway lines: the red and blue lines are straightforward radials, the green line is a straightforward circumferential, the yellow line mixes radial and circumferential as criticized in my previous post, the pink line mixes radial and circumferential in the other manner, which I will describe in this post.

The reason the yellow line is going to underperform in this system is that it fails as a radial: it does not go to city center, which has the largest concentration of destinations for transit users. People who have equal access to the red and yellow lines, north and south of city center, are much likelier to choose the red line, which takes them where they want to go. The green line fails as a radial too, but has the positive features of a circumferential: it only serves relatively nearby neighborhoods, which are likely to be denser and produce more riders per unit length; it connects to every line in the system; it allows people to connect between two radial lines without going through the congested city center; it has no dominant direction at the peak, so trains are unlikely to be full in the peak direction and empty in the reverse-peak direction. The yellow line has none of these features, unless one wants to connect between the western legs of the blue and pink lines.

The pink line still works as a radial. Its northeastern leg is a straightforward radial, but even its southwestern leg  works as a radial for people who live west of the yellow line and wish to commute to city center. In this way, it is not truly a mixture of radial and circumferential elements the way the yellow line is, but is simply a radial with a circumferential element tacked on at the end.

Whether the pink line’s circumferential tail works must be evaluated against two alternatives: build nothing, and build a radial leg. This is because in an incrementally-built transit system, the radial parts of the line are typically built first, and the circumferential tail is tacked on as a later extension. In the no-build case, the pink line’s southwestern leg would simply be shorter than the other radial legs in this system. In the radial case, the pink line’s southwestern leg would look symmetric with the northeastern leg. This depends on the following factors:

  1. The strength of the radial alternative. If the radial alternative is strong, then this discourages building the circumferential extension, and vice versa. The radial alternative can be weak in several ways: the southwestern quadrant of the city depicted above may be already replete with radial transit and not need more; the population density in the neighborhoods that would be served by the radial option may be low; and the city’s layout may not be the above-depicted perfect circle, so that there is nowhere for the line to turn except sideways.
  2. The strength of the corridor that would be served by the circumferential leg. The leg can never be a complete circle, so it must be evaluated as a rapid transit line on an individual street or corridor. This far out of city center, transit demand on each route is unlikely to be high, but there may well be exceptions, for example if there is a linear secondary CBD. For example, while Seoul Metro Line 2 is fully circumferential, one of its segments follows a Tehran Avenue, a major street in Gangnam with high transit demand, which would justify a subway even if it weren’t part of a large circle.
  3. The strength of the circumferential transit demand from the end of the potential circumferential extension to the radial segment. In the depicted city, there may be strong demand for east-west transit south of the CBD, and the circumferential pink line is then better at serving it than connecting between the red and yellow lines via the blue line.

The original impetus for this post, as noted at the beginning, is a comment challenging me for my support of an extension of Second Avenue Subway Phase 2, going under 125th Street from the planned terminus at Lexington Avenue to Broadway, with stations at the intersection with each preexisting subway line. I contend that in this case, all three factors above point to a very strong circumferential extension. In order:

  1. The radial alternative is to extend Second Avenue Subway to the north, to the Bronx, presumably under Third Avenue, but according to some railfans also under University Avenue. This is problematic, for three reasons. First, the Bronx already has many north-south lines feeding into Manhattan trunk lines, with mediocre ridership. The Manhattan trunk lines are overloaded, but mostly with traffic coming from the Upper East and West Sides, Harlem, and Washington Heights. Second, Third Avenue is close to the Harlem Line, which could be used for local transit if fares and schedules are integrated with the subways and buses. And third, the plan for Second Avenue Subway is for the line to turn west at 125th toward Lexington, since 125th and Second is not as compelling a destination, and this makes it easier to extend the line to the west than to the north.
  2. 125th Street is a very busy street, and acts as the main street of Harlem. Transit demand is high: four bus routes use the street, with a total of 32,630 boardings per weekday on 125th Street, exclusive of other segments of those routes. This count misses people who board elsewhere and get off on 125th, but conversely assigns people who board on 125th and get off elsewhere to this street and not the other segment. But with this caveat in mind, this points to about 11,000 weekday riders per route-km, ahead of New York’s busiest bus per unit length (the M86, with about 7,000), and not far behind the subway average (15,000). This is despite the fact that, in my experience going between Columbia and the Metro-North station at Park Avenue, those buses are not faster than walking.
  3. East-west transit in Uptown Manhattan consists of Pokey-winning crosstown buses; the 125th Street buses are as slow on 125th. An underrated feature of Second Avenue Subway Phase 1 is that it will soon enable a two-seat subway ride from the Upper East Side to the Upper West Side, West Harlem, and Washington Heights. However, this option will require connecting at Times Square, and is useful mainly for people in the southern areas of the Upper East Side connecting to the 1/2/3 rather than to the A/B/C/D. A two-seat ride based on going up Second Avenue to 125th Street and thence connecting to the 2/3, A/B/C/D, or 1 would enable more connections, many without any backtracking. This could have a potential cascading effect on all Uptown east-west buses, and not just those using 125th Street.

Of course, a Second Avenue Subway extension on 125th Street cannot be exactly like the pink line in the diagram above, because a key feature of it is that the circumferential part is not in fact near the outer end of the city. It’s barely 5 km north of the northern edge of Midtown, not even halfway from Midtown to the northern ends of most preexisting north-south subway lines. This is how it can have such high residential and commercial density and strong transit demand. Much farther north, Fordham Road is a very strong bus corridor, with about 4,500 weekday riders per route-km on the Bx12, but this is at much higher speed than in Manhattan, about 13 km/h rather than 5 km/h. An extension of the A east toward the Bronx under Fordham would underperform, because Fordham just doesn’t have that much demand; but 125th does.

The result of this discrepancy is that in a small city, one whose subway system is only about as large as in the diagram, it’s unlikely that such circumferential extensions would work. A radial line built all the way out is going to have as its terminus either a relatively low-density area or an anchor point, such as a commercial center or big housing project, neither of which lends itself to a strong continuous circumferential corridor. A radial line built part of the way to the edge of the city could potentially find a Tehran Avenue or a 125th Street, but if the system is small, with many key outlying neighborhoods still unserved, then it is usually best to keep extending lines outward.

The factors that conspire to make a 125th Street subway extension work are in place precisely because New York already has a large, mature subway network, in which Second Avenue Subway is a relief line. Certainly the projected demand on Second Avenue is very high, but the East Side is already served by a north-south subway 500-600 meters to the west of this line; it’s being built because this subway is overcrowded, not because the East Side has no access. This means that there’s more leeway with choosing what to do with the line once it reaches Harlem – after all, the Bronx subways are not overcrowded, and do not need relief.

Whereas mixed lines like the above-depicted yellow line are always bad transit, mixed lines like the pink line, in which the circumferential part is farther out than the radial part, are potentially an option for large cities that already have many rapid transit lines. They are especially useful for providing connections between closely parallel radial lines when other crosstown transit options are slow, and should be considered as extensions for relief lines, provided the radial lines farther out do not need relief as well.

Northeast Corridor, 95% Cheaper: Frankford Junction

Amtrak’s plan for high-speed rail on the Northeast Corridor, at a cost of about $290 billion depending on the exact alternative chosen, is unacceptably costly. I went into some details of where excess cost comes from in an older post. In this post, I hope to start a series in which I focus on a specific part of the Northeast Corridor and propose a cheaper alternative than what the NEC Future plan assumes is necessary. The title is taken from a post of mine from four years ago; since then, the projected costs have doubled, hence the title is changed from 90% cheaper to 95% cheaper. In this post, I am going to focus on untangling Frankford Junction.

Frankford Junction is one of the slowest parts of the Northeast Corridor today south of New York. It has a sharp S-curve, imposing a speed limit of 50 mph, or 80 km/h. While worse slowdowns exist, they are all very close to station throats. For example, Zoo Junction just north of Philadelphia 30th Street Station has a curve with radius about 400 meters and an interlocking, so that superelevation is low. The speed limit is low (30 mph, or 50 km/h), but it’s only about 2 km out of the station; it costs about 2 minutes, and with proper superelevation and tilting the speed limit could be doubled, reducing the time cost to 25 seconds. In contrast, Frankford Junction is about 13 km out of 30th Street Station; an 80 km/h restriction there, in the middle of what could be a 200 km/h zone, makes it uneconomic for trains to accelerate to high speed before they clear the junction. This impacts about 4 km, making it a 108-second slowdown, which can be mitigated by either more tilting or a wider curve. In reality, a mixture is required.

The NEC Future plan for high-speed rail, the $290 billion Alternative 3, avoids the Frankford Junction S-curve entirely by tunneling under Center City and building a new HSR station near Market East, a more central location than 30th Street; see PDF-pp. 19, 20, and 78 of Appendix A of the environmental impact statement. This option should be instantly disposed of: 30th Street is close enough to the Philadelphia CBD, and well-connected enough to the region by public transit, that it is no worse a station choice than Shin-Osaka. The Tokaido Shinkansen could not serve Osaka Station as a through-station without tunneling; since Japan National Railways wanted to be able to extend HSR onward, as it eventually did with the Sanyo Shinkansen, it chose to serve Osaka via a new station, Shin-Osaka, 3 km away from the main station. Given the expense of long tunnels under Philadelphia, the slightly less optimal station today should be retained as good enough.

A lower-powered plan providing some HSR functionality, Alternative 2, does not include a new tunnel under Philadelphia, but instead bypasses Frankford Junction. On Appendix A, this is on PDF-pp. 19, 20, and 70. Unfortunately, the bypass is in a tunnel, which appears to be about 4 kilometers. The tunnel has to cross under a minor stream, Frankford Creek, adding to the cost. Instead, I am going to propose an alignment that bypasses the tunnel, with moderate takings, entirely above ground.

In brief, to minimize trip times without excessive construction, it is best to use the highest superelevation and cant deficiency that HSR technology supports today. The maximum superelevation is 200 mm, on the Tokaido Shinkansen (link, PDF-p. 41); there were plans to raise superelevation to 200 mm on the Tohoku Shinkansen, to permit a maximum speed of 360 km/h, but they were shelved as that speed created problems unrelated to superelevation, including noise, pantograph wear, and long braking distances. The maximum cant deficiency on existing trainsets capable of more than 300 km/h is about 180 mm, including the E5/E6 Shinkansen and the Talgo 350 and Talgo AVRIL. Tilting trains capable of nearly 300 mm cant deficiency exist, but are limited to 250 km/h so far. With 200 mm superelevation and 175 mm cant deficiency, speed in meters per second equals square root of (2.5 * curve radius in meters); the minimum curve radius for 200 km/h is then 1,235 meters.

An S-curve requires some distance to reverse the curve, to avoid shocking the train and the passengers with a large jerk, in which they suddenly change from being flung to the right to being flung to the left. If you have ridden a subway, sitting while the train was decelerating, you must have noticed that as the train decelerated, you felt some force pushing you forward, but once the train came to a complete stop, you’d be pulled backward. This is the jerk: your muscles adjusted to being pushed forward and resisting by pulling backward, and once the train stopped, they’d pull you back while adjusting back to the lack of motion. This is why S-curves built a long time ago, before this was well-understood, impose low speed limits.

With today’s computer-assisted design and engineering, it’s possible to design perfect S-curves with constant, low jerk. The limits are described in the above link on PDF-pp. 30 and 38. With the above-described specs, both sets of standards described in the link require 160 meters of ramp. For a single transition from tangent track to a fully superelevated curve, this can be modeled very accurately as 80 meters of straight track plus the circular curve (half the transition spiral is within the curve); the displacement from an actual spiral curve is small. For an S-curve, this requires double the usual transition, so 160 meters of tangent track between the two circles; bear in mind that this distance grows linearly with speed, so on full-speed 360 km/h track, nearly 300 meters are required.

Here is a drawing of two circles and a tangent track between them. The curve of course consists only of a short arc of each circle. The straight segment is a little less than 700 meters, which permits a gentle spiral. The curves have radius 1,250 meters. Takings include a charter school, a wholesale retailer, an auto shop, and what appears to be industrial parking lots, but as far as I can tell no residences (and if I’m wrong, then very few residences, all very close to industrial sites). The charter school, First Philadelphia Preparatory, is expanding, from 900 students in 2012-3 to an expected 1,800 in 2018-9. School construction costs in Pennsylvania are high, and $100 million is expected for a school of that size; see also table 5 on PDF-p. 7 here for national figures. The remaining takings are likely to cost a fraction of this one. Even with the high cost of takings, it is better to realign about 2 kilometers of track above-ground, at perhaps $150 million, than to build 4 km of tunnel, at $1.5 billion; both figures are based on cost items within the NEC Future . This represents a saving of about 83% over Alternative 2, which is projected to cost $116-121 billion excluding rolling stock (PDF-p. 42 of chapter 9 of the EIS).

Given the long spiral length, it may be feasible to avoid the charter school entirely. This would probably require shrinking curve radius slightly, permitting 180 or 190 km/h rather than 200 km/h. However, the travel time cost is measured in seconds: with about 11 km from the end of Zoo Junction to the northern end of Frankford Junction, of which 1 is required just to accelerate to speed, the difference between 200 and 180 km/h is 20 seconds. Further savings, reducing this time difference, are possible if the speed limit without taking the school is 190, or if trains accelerate to 200, decelerate to curve speed, and accelerate again to the north. This option would improve the cost saving over Alternative 2 to about 90%.

The correct way forward for affordable improvement of the Northeast Corridor is to look for ways in which expensive infrastructure can be avoided. If a tunnel can be replaced by a viaduct at the cost of a few extra takings, it should be. If an expensive undertaking can be avoided at the cost of perhaps 10 seconds of extra travel time, then it probably should be avoided. There should be some idea of how much it’s acceptable to spend per minute of marginal travel time saving, by segment: the New York-Philadelphia segment has the heaviest traffic and thus should have the highest maximum cost per unit of time saved. But even then, $100 million for 20 seconds is probably too high, and $100 million for 10 seconds is certainly too high.

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 than 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.

Public Transit Unions

In this post, I would like to explain an observation: public transit workers are unionized even in countries where few workers belong to a union, such as the US and the UK. Attempts by management to win concessions from the unions have often led to prolonged strikes, for example the 108-day strike by SEPTA workers in 1983. This is not just the public sector: the private railroads in the US are unionized, and in 1964 the Florida East Coast Railway had a year-long strike. Nor is this because the public operators and private railroads have a unionized legacy: many private bus shuttles used by Bay Area tech firms to get workers from San Francisco to Silicon Valley offices have unionized drivers, including Facebook and Google, even though the tech industry as a whole is predominantly non-union. Public transportation workers, especially on-board crew, are in a position of strength, and I would like to explain why.

First, let us recount how unions work. At their heart is collective bargaining: the union negotiates wages and benefits for the entire membership. An individual worker who is paid too little can quit, which is unlikely to cause the employer much concern; a union can launch a strike, thereby getting higher wages and better work conditions than each individual worker could obtain alone.

In order to be able to collectively bargain, there needs to be a collective in the first place, which means two separate things:

  1. Politically, there needs to be a sense of solidarity among the workers. The workers need to see each other as comrades, or as colleagues, and not as competitors. They need to feel like the union represents their interest. This is unlikely to happen in industries where there is substantial competition for promotions to managerial roles, but easier in industries with clear separation between line workers and managers. It is also unlikely to happen in industries with rapid turnover of employees.
  2. Economically, there needs to be a reasonable way to set a uniform wage scale. This means that the work done by the various employees in each category must be interchangeable, or close enough to it that wages can be made equal. In turn, this requires that the job not have a strong sense of merit, in which some workers are persistently much more productive than others. Productivity differences should be related to seniority, or easily worked into wage agreements (for examples, sales agents can collectively bargain for a uniform commission structure). It’s fine if there is differentiation into several job categories, but then it’s best if this differentiation is rigid, so that workers in each group do not often have to do the job of workers in other groups.

Conversely, if the union goes on strike, management has tools to fight back, including the lockout, or more commonly hiring strikebreakers. To deter management from doing so, the union can exercise peer pressure on people not to scab (condition 1 above), but it also union needs to also fulfill a third condition:

  1. The job must be skilled enough that it is hard for the employer to hire and train strikebreakers quickly. On a nationwide basis this makes unionization easier in a tight labor market, hence socialist support for monetary policy that prioritizes full employment over price stability. But on a per-industry basis, this condition requires some difficult pipeline that workers must go through: a degree, long training, apprenticeship, or bespoke familiarity with the project at hand.

Conditions 2 and 3 are in tension, since skilled jobs are more likely to involve workers with different levels of productivity. For example, retail workers fulfill condition 2, but are easy to replace if they go on strike and the labor market is not tight. In contrast, programmers easily fulfill condition 3, in the sense that if the entire development team on a project quits, it will be difficult for the company to find a new one and get it up to speed, but because there is a wide range of productivity levels, it makes little sense for programmers to all be paid the same. Silicon Valley’s business culture, in which developing a product fast is more important than establishing a business culture, and turnover is encouraged, also makes it hard to establish meaningful solidarity among software developers.

In the intersection between these three conditions lie a set of job descriptions in which there is a strong sense of professionalism, to meet condition 3, but a weak sense of merit, to meet condition 2. These jobs are typically static in the sense of not changing too much over the years, which makes it ideal for a person to do the same thing for their entire life, learning to adopt new technologies gradually as they are introduced but not having to change their entire skillset. Often, the industries these jobs are in are static as well, whence they are more easily done by the public sector, or by large conglomerates that have been around for generations, such as the private US railroads.

Commercial drivers – of buses, trucks, trains, planes – are a major example of people who satisfy all three conditions. One racecar driver can be better than the next by being faster, but in the commercial sector, speeds are determined by the equipment, the schedule, and the safety standards. A train driver can be better than another on the margins, by responding more quickly to an obstacle on the tracks, or paying attention to the posted schedule better, but both of these aspects depend more on external factors, such as the signal system, than on driver skill. Train schedule padding, accounting for suboptimal driver behavior such as beginning to brake too early but also for propagating delays and passengers who take too long to board or alight, consists of a few percent of total travel time: in its peer review of California High-Speed Rail, JR East proposes 3-5% (PDF-p. 10); and a Swedish study for high-speed rail mentions a 0.9-2.3% discrepancy in energy consumption based on driver behavior (PDF-p. 12) and a total schedule pad equal to about 7% of travel time (PDF-p. 24). The productivity difference, or in other words individual merit, is too small to challenge the logic of a uniform wage scale.

Instead of individual merit, commercial drivers have professionalism. A train driver is expected to fulfill certain criteria to ensure safety first and punctuality second, which requires considerable study of the route of the train, the signal systems, the dispatching codes, the correct way to respond to various unforeseen circumstances. Unlike individual car drivers, commercial drivers are not permitted to take small risks in other to go faster, and learning how to pilot a vehicle safely takes some time; all of this is true manifold if the vehicle in question is a plane, leading to arduous certification requirements. In this setting, even in an environment of absolute control by management, there’s little reason to have different payscales – at most, management can penalize workers who make mistakes.

For the same reasons that train drivers have standards of professionalism, it is easy for them to form a cultural group with internal solidarity. They have their own knowledge set and jargon, as anyone who has tried reading threads on railfan forums knows. The transportation industry changes slowly enough, in terms of both travel demand and technological progress, that most train drivers can expect to work for the same company for decades. Even bus drivers, in an industry that’s less dependent on physical plant, can expect to move between bus operators.

The other major category of public transportation workers, maintenance workers, is not as clear-cut. There is certainly a difference in merit – some people just fix things faster than others. But at the same time, the importance of safety is such that giving financial incentive to working faster can lead to shoddy work. Instead, there are extensive regulations, developed by national safety authorities as well as internally by rail operators, specifying which tasks need to be performed and at what intervals.

Unlike train drivers, maintenance workers aren’t interchangeable – they have more specific job titles. But these job titles often lend themselves to easy categorization, such as electricians and welders. Those have their own standards, and the potential for major accidents encourages uniformity of credentials and of wages, while the complexity of the machinery these workers operate ensures that they must be skilled. This leads to the same presence of professionalism without differential individual merit seen in the case of train drivers, and ensures all three conditions facilitating unionization are present.

In a healthy company, technology progresses as fast as it can given the requirements of the industry, and the union rules are reasonable. Wages and benefits are higher with collective bargaining than without almost by definition, but they cannot be massively higher – those are skilled workers, who are not easily replaceable. In environments where the rules are unreasonable – perhaps the certification requirements are more onerous than necessary, perhaps labor-saving technologies are not used, perhaps the work rules are not suitable for a modern operation – management cannot easily force the union’s hand. Even when three people do the job of one, as in the case of US commuter rail operations with conductors and assistant conductors, labor is in a position of power, and reform-minded managers cannot easily hire strikebreakers.

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:

greenbelt1

 

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:

greenbelt2

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.

Now, you may ask, if there’s no demand for new urban transit lines, why is there demand for new highways? After all, if there was not much regional travel into these suburbs historically, why would there be enough car traffic to justify high investment into roads? The answer is that at low levels of traffic, it’s much cheaper to build a road than to build and operate a railway. This example city has no traffic generators in the greenbelt, except perhaps parks, so roads are cheap to build and have few to no grade crossings to begin with, making it easier to turn them into full freeways. The now-dead blog Keep Houston Houston made this point regarding a freeway in Portland, which was originally built as an arterial road in a narrow valley and had few at-grade intersections to be removed. At high levels of demand, the ability to move the same number of people on two tracks as on fourteen lanes of freeway makes transit much more efficient, but at low demand levels, rail still needs two tracks or at least one with passing sidings, and high-speed roads need four lanes and in some cases only two.

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.

A Theory of Zoning and Local Decisionmaking

This weekend there’s a conference in the US, YIMBY 2016, by a national network of activists calling for more housing. I am not there, but I see various points raised there via social media. One is a presentation slide that says “NIMBYism is a collective action problem: no single neighborhood can lower prices by upzoning; might still be in everyone’s interest to upzone at city/state level.” I think this analysis is incorrect, and in explaining why, I’d like to talk about a theory of how homeowners use zoning to create a housing shortage to boost their own property values, and more generally how long-time residents of a city use zoning to keep out people who are not like them. In this view,zoning is the combination of a housing cartel, and a barrier to internal migration.

For years, I’ve had trouble with the housing cartel theory, because of a pair of observations. The first is that, contra the presentation at YIMBY, zoning is driven by homeowners rather than by renters; for an overview, see the work of William Fischel. The second is that restrictive zoning typically correlates with local decisionmaking, such as in a neighborhood or small city, while lax zoning typically correlates with higher-level decisionmaking, such as in a city with expansive municipal boundaries or in an entire province or country; see below for more on this correlation. These two observations together clash with the housing cartel theory, for the inverse of the reason in the above quote from the YIMBY presentation: it’s more effective to create a housing shortage in a large area than in a small one.

To a good approximation, land value equals (housing price – housing construction cost)*allowed density. If a small municipality upzones, then as in the quote, housing price doesn’t change much, but allowed density grows, raising the price a homeowner can get by selling their house to developers who’d build an apartment building. In contrast, if a large municipality upzones then housing prices will fall quite a bit as supply grows, and depending on the price elasticity, land value might well go down. If x = housing price/housing construction cost and e = price elasticity for housing, i.e. price is proportional to density^(-1/e), then maximum land value occurs when x = e/(e-1), provided e > 1; if e < 1 then maximum value occurs when x is arbitrarily large. Price elasticity is much higher in a small municipality, since even a large increase in local housing supply has a small effect on regional supply, limiting its ability to reduce prices. This implies that, to maximize homeowner value, small municipalities have an incentive to set density limits at a higher level than large municipalities, which will be seen in faster housing growth relative to population growth.

What we see is the exact opposite. Consider the following cases, none a perfect natural experiment, but all suggestive:

1. In the Bay Area, we can contrast San Francisco (a medium-size urban municipality), San Jose and generally Santa Clara County (San Jose is medium-size for a central city and very large for a suburb), and San Mateo County (comprising small and medium-size suburbs). San Mateo County is by far the stingiest of the three about permitting housing: over the last three years it’s averaged 1,000 new housing units per year (see here); in 2013, the corresponding figures elsewhere in the Bay Area were 2,277 new housing units in San Francisco and 5,245 in Santa Clara County. Per thousand people (not per housing unit), this is 2.63 in San Francisco, 2.73 in Santa Clara, and 1.31 in San Mateo. In Alameda County, comprising medium-size cities and suburbs, with a less hot housing market because of the distance from Silicon Valley jobs, growth was 2,474 units, 1.51 per 1,000 people. In small rich Silicon Valley municipalities like Palo Alto and Menlo Park, NIMBYs have effectively blocked apartment construction; in much larger and still rich San Jose, the city has a more pro-growth outlook.

2. Among the most important global cities – New York, Paris, London, and Tokyo – Tokyo has by far the fastest housing stock growth, nearly 2% a year; see article by Stephen Smith. In Japan, key land use decisions are made by the national government, whereas in Paris, London, and New York, decision is at a lower level. London builds more than New York and Paris; its municipal limit is much looser than Paris’s, with 8.5 million people to Paris’s 2.2 million even though their metro areas have similar populations. New York has a fairly loose limit as well, but the development process empowers lower-level community boards, even though the city has final authority.

3. Canada has a relatively permissive upzoning process, and in Ontario, the planning decisions are made at the provincial level, resulting in about 1.3% annual housing growth in Toronto in the previous decade; in the same period, San Jose’s annual housing growth was about 1% and San Francisco’s was 0.9%.

4. France has recently made a national-level effort to produce more housing in the Paris region, especially social housing, due to very high housing prices there. Last decade, housing production in Ile-de-France was down to about 30,000-35,000 per year, averaging to 2.6 per 1,000 people, similar to San Francisco; see PDF-pp. 4-5 here and the discussion here. With the new national and regional effort at producing more social housing, plans appear to be on track to produce 30,000 annual units of social housing alone in the next few years; see PDF-p. 6 here. With 7,000 annual units within city limits, Paris expects to build somewhat more per capita than the rest of the region.

In France, the combination of a national focus on reducing housing burden and the observation that higher-level decisionmaking produces more housing makes sense. But elsewhere, we need to ask how come homeowners aren’t able to more effectively block construction.

My theory is that the answer involves internal migration. Consider the situation of Palo Alto: with Stanford and many tech jobs, it is prime location, and many people want to move there. The homeowners are choosing the zoning rule that maximizes their ability to extract rents from those people, in both the conventional sense of the word rent and the economic sense. Now consider decisionmaking at the level of the entire state of California. California can raise housing prices even more effectively than Palo Alto can by restricting development, but unlike Palo Alto, California consists not just of residents of rich cities, but also of residents of other cities, who would like to move to Palo Alto. In the poorer parts of the state, there’s not much point in restrictive zoning, because there isn’t that much demand for new housing, except perhaps from people who cannot afford San Francisco or Los Angeles and are willing to endure long commutes. On the contrary, thanks to the strength of internal migration, a large fraction of prospective residents of Palo Alto live elsewhere in California. Nor do people in poor areas, where houses aren’t worth much as investments, gain much from raising house prices for themselves; the ability to move to where the good jobs are is worth more than raising housing prices by a few tens of thousands of dollars. This means that the general interest in California is to make Palo Alto cheaper rather than more expensive. The same is true of Japan and Tokyo, or France and Paris, or Ontario and Toronto.

While superficially similar to the point made in the presentation quoted at the beginning of this post, my theory asserts the opposite. The issue is not that individual municipalities see no benefit in upzoning since it wouldn’t reduce rents by much. It’s that they see net harm from upzoning precisely because it would reduce rents. It is not a collective action problem: it is a problem of disenfranchisement, in which the people who benefit from more development do not live in the neighborhoods where the development would be taking place. High-level decisionmaking means that people who would like to move to a rich area get as much of a vote in its development policy as people who already live there and have access to its amenities, chief of which is access to work. It disempowers the people who already have the privilege of living in these areas, and empowers the people who don’t but would like to.

Individual rich people can be virtuous. Rich communities never are. They are greedy, and write rules that keep others out and ruthlessly eliminate any local effort to give up their political power. They will erect borders and fences, exclude outsiders, and demagogue against revenue sharing, school integration, and upzoning. They will engage in limited charity – propping up their local poor (as San Francisco protects low-income lifelong San Franciscans via rent control), and engaging in symbolic, high-prestige giving, but avoid any challenge to their political power. Upzoning is not a collective action problem; it is a struggle for equal rights and equal access to jobs regardless of which neighborhood, city, or region one grew up in.

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.