Linear Compression: How HSR is Like Rapid Transit

A post from last month on Keep Houston Houston notes how high-speed rail transformed Japanese geography to the point that it’s faster to get from Osaka to Nagano via Tokyo than direct despite a doubling of travel distance. The same comment could equally be made about rapid transit within a city: for example, for some origin-destination pairs in Vancouver, it’s faster to go the long way around the Millennium Line than to take a direct bus, and the same principle works in every other city. For both modes of transportation, this comes from high capital costs and high capacity, which make them useful primarily on the thickest travel markets, which tend to be radial around the largest center.

The next step is to look at the effect this change in transportation on economic geography. As I’ve argued before, in both cases the result reinforces preexisting centralization. This is both feedforward and feedback: a dominant city creates enough travel demand to support an HSR network and a dominant CBD creates enough demand to justify digging subways, while at the same time the quickness of travel along the rapid lines makes people emphasize connections along them and deemphasize others.

Concretely, this means that in Manhattan, with its wealth of north-south subway lines and paucity of east-west lines north of Midtown, people identify with the East Side or the West Side. Although the Upper East Side and Upper West Side are socially and demographically similar and are geographically close to each other, the social connections I’ve seen are primarily north-south. A gaming group I participate in many of whose members have recently moved to New York concentrates on the West Side since the earliest members moved to the Upper West Side, and so more people who were living or looking to live in Brooklyn or Queens are moving to Uptown Manhattan in general and the West Side specifically. The subway helps the Greater Upper West Side project influence as far north as Inwood. In contrast, the east-west connection is deemphasized to the point that people I know talk up the cultural differences between the Upper East Side and the Upper West Side, even ones who are not from either neighborhood and are not from the usual high-income demographic (though, of course, the two neighborhoods are culturally dominant and can discuss their own issues via mass media).

I do not know if the above trend is also the case for countries with developed HSR networks. However, another corollary trend is. The importance of the CBD and areas easily accessible from it is that the CBD becomes the more or less neutral choice for where people from different sectors can meet. Midtown can be easily accessed from the Greater Upper West Side, Greater Williamsburg, Greater Bed-Stuy, and so on. This effect then not only reinforces the rapid transit lines but also their nodes, to the point of creating possible centers around accidental transfer stations. In Vancouver, the Commercial Drive area functions as a major meeting location for social groups that are too widely distributed around the metro area for a place in Burnaby or along the Canada Line to be as acceptable. Although the Commercial Drive area hasn’t turned into a CBD and most likely never will, Midtown Manhattan became a CBD largely because of subway lines leading to Uptown Manhattan and Queens. Social meetings and job centers obey similar geographic rules.

In a fractal manner, in each sector there can also be a relatively neutral meeting location when the primary CBD is too expensive or too far, based on either a highway network (for example, White Plains for Westchester) or a rapid transit network (for example, Downtown Brooklyn for all of Brooklyn except Eastern Brooklyn), or even an arbitrary choice of zoning that then becomes self-reinforcing (for example, Metrotown in Burnaby). It promotes a perverse kind of equality, one in which no sector is favored over others, and the social hierarchy is based on the ease of getting to the center, in a similar manner to how in former British colonies with few whites, English sometimes arises as the politically neutral choice of language (or French in former French colonies, etc.), replacing a hierarchy between speakers of different local languages with a hierarchy between people with varying degrees of English fluency.

The exact same node effect can be observed in HSR. Japan’s become more centralized around Tokyo since the Shinkansen was built. In France and Britain there’s heavy centralization, going back many decades; from the start, the lines connecting the capital to the major secondary cities were treated as fast main lines while the others were slower branches. In South Korea, there’s mixed evidence about the role of the KTX in promoting development in secondary cities, but there has been growth in outer exurbs of Seoul that the KTX put within reasonable commute distance, such as Cheonan and Asan, even beyond the general growth of Seoul’s suburbs in the last 30 or so years. It is likely that of the secondary cities, the one emerging the best from this development is Daejeon, both the closest to Seoul and the junction of the lines to Busan/Daegu and Gwangju; for what it’s worth, even before the KTX opened, its metro area had faster population growth than the other major metro areas, excluding satellite metro areas that should really be thought of as suburbs of larger cities.

The meaning of this analogy is that an urban rapid transit network and a national HSR network will look similar. We can now extend the analogy and think in terms of connecting transportation. S-Bahn/RER-style regional rail generally involves routing preexisting commuter lines through new tunnels to provide rapid transit-style urban service; this is analogous to making HSR use legacy lines at lower speed in parts of the system that don’t justify the construction costs of a new line. Branch regional lines and buses feed people into rapid transit stations, in the same manner that legacy rail lines feed people into HSR stations. Some of the alignment questions, such as whether to tunnel or build complex viaducts to reach secondary city centers or to go around them on easier rights of way to save money, are similar, though the answers are often different (i.e. the benefits of the higher-cost alternative are much higher for rapid transit than for HSR since more people ride local transit than intercity transit, while the extra costs are comparable).

It can even explain some of the political coalitions. Rapid transit and HSR are both high-construction cost, high-capacity, long-term investments. They scale up but not down, and therefore cannot be undertaken by a cheeky entrepreneur with a moderate amount of venture capital; they are instead built by governments or very large conglomerates or sometimes both combined, and require careful planning (for example, upzoning) to ensure economic development patterns can reorient along the new infrastructure. They are also signature investments generating a lot of press, to the point that in some cases they can pursued purely for the ribbon cutting, while other forms of rail usually aren’t unless a politician is trying to oversell them as equivalent to rapid transit or HSR but cheaper.

SkyTrain and UBC

I live about 3 minutes from an express bus stop, where I can get the express bus and be at UBC within 15 minutes, whereupon I can walk from the diesel bus loop to my classroom in 6 minutes. Since I teach at 10 in the morning, it means I should leave around 9:30 or just before and then with rush hour headways I can be guaranteed not to be late to my own class. Unfortunately, because classes start on the hour, everyone wants to ride the last bus that makes the 10 am classes, and by the time this bus gets to my neighborhood, it is full. To guarantee getting on a bus I need to be at the bus stop by 9:20 or not much later, which since I have no real reason to show up to campus 15 minutes ahead of time lengthens my effective commute to 40-45 minutes. A bus that is in principle faster door-to-door than any proposed SkyTrain extension, which would serve my area at a much farther away station, becomes more than 10 minutes slower at the time of day relevant to me.

Vancouver has a general problem with passups – that is, passengers at a bus stop who have to let a full bus go. A list of the bus stops with the most passups is dominated by UBC’s peak caused by classes starting and ending at a synchronized time: eight of the top ten stops are for east-west buses serving UBC, and at those stops the passups are concentrated in the AM peak for westbound buses and the PM peak for eastbound ones. Of those eight stops, two, on the 49, are partially connections to the Canada Line (compare passups east and west of Cambie here), but the six on the 99-B are not, since a sizable fraction of riders ride end to end and there are substantial passups west of Cambie as well.

The demand generated by a traditional CBD can be smoothed with flex-time work and with a general spread of the peak around a peak half hour. With a university this is not feasible: to ensure maximum flexibility for students’ class schedule classes should be synchronized. When I was at NUS, a commuter university like UBC, I had a similar problem with full buses heading from campus to the subway stations after classes. Because UBC is nowhere near SkyTrain, its demand has to be spread among many bus routes, and is so great that it’s clogged not just the 99-B but also parallel routes such as the 25 and relief lines such as the 84.

The only alternative for investment in the Broadway corridor that has enough capacity to meet this demand is a full SkyTrain option. Any option that relies on a connecting bus part of the way not only won’t solve the capacity problem, but might even make it worse by concentrating all the UBC-bound demand at the westernmost SkyTrain station on Broadway, at either Granville or Arbutus. Today, people who take the Millennium Line can use the 84, which is faster than the 99-B; any extension of the Millennium Line west, even just to Cambie to complete the gap from Commercial to the Canada Line, is likely to concentrate demand on one corridor, overwhelming the truncated 99-B even further.

A light rail option probably has enough capacity, but does very little for Central Broadway or for completing the SkyTrain gap, and would also require pedestrian-hostile reconfiguration of stoplights and left turn cycles, making crossing the street even harder than it already is. UBC, which doesn’t care about Vancouver’s own needs, advocates an all-light rail option, while the city, which doesn’t care about UBC’s, wants a subway initially going as far west as Arbutus with a bus transfer to the west. A combo option with SkyTrain to Arbutus and light rail the rest of the way exists (Combo A in the alternatives analysis), but is almost as expensive as a full subway. The ridership projection for the combo option is almost even with that of a full subway, but such a projection is based on optimistic assumptions about transfer penalties and passengers’ willingness to travel on slower transit: the combo option is slower by about 7 minutes than the full subway from most preexisting SkyTrain stations as well as from Central Broadway, and requires an extra transfer for people traveling from the Millennium Line or Central Broadway.

Because the project has a $3 billion price tag, various critics have already begun complaining that it’s needlessly expensive (in reality, the inflation-adjusted projected cost per rider is the same as those of the Millennium, Canada, and Evergreen Lines) and proposing inferior solutions, and I believe that this cost is why the city and Translink are thinking of truncating the extension to Arbutus and only doing the rest later. It’s fine to spend a higher sum on the combination of the Canada and Evergreen Lines, which look nice on a map and make a lot of suburban mayors happy, but when it’s just one line that more or less stays within the city it’s too expensive and needs to be chopped into phases.

The other issue is that SkyTrain extensions have been more about shaping than about serving, i.e. serving areas that can be redeveloped rather than ones that are already dense. Look at the density map by census tract here: the residential density on Central Broadway and in the eastern parts of Kits is high, comparable to that of the census tracts hosting most SkyTrain-oriented developments. Even as far west as Alma there’s fairly high residential density. However, this is low-rise density, distributed roughly uniformly in the census tract, rather than clustered in a few high-rise buildings next to the SkyTrain stations. High-rises are possible throughout the corridor – there already are a few near the future Alma and Sasamat stops – but because of Point Grey’s affluent demographic it’s easy to write it off as not densifiable. Empty or very low-density plots are easier to redo from scratch than an existing neighborhood, even if the neighborhood already has enough development to justify a subway.

I suspect part of the problem comes from the context in which Vancouver’s TOD is located in. The Expo Line follows a private right-of-way with pedestrian-hostile streets connecting to stations, and the Millennium Line is elevated over the mostly sidewalk-free Lougheed Highway. The fastest way to get from some houses that are close to SkyTrain on a map to the station is to walk through mall parking lots. The walking range of SkyTrain stations located in unwalkable parts of Burnaby is not as high as it would be at ones located in a walkable urban context. At the level of how many people would live within a kilometer of SkyTrain, Kits and Central Broadway are already outperforming most of the Expo Line’s TOD, and even at the 500-meter range they do quite well; but in Burnaby the relevant distance is much shorter, and this may affect Translink’s ridership projections elsewhere in the metro area.

The only medium- and long-term solution is to find the $3 billion for the UBC extension, just as the metro region will have spent $3.5 billion in 10 years on the Canada and Evergreen Lines. Nothing else works for both UBC and Central Broadway; the counterarguments are based on generalizing from a different urban context; the difference-splitting intermediate solutions make some of the transit problems even worse than they are. It is always wrong to downgrade projects just because of a sticker shock, and if a very large project still has a good cost-benefit ratio then it’s a good investment to raise taxes or borrow money to fund it.

The Magic Triangle: Infrastructure-Timetable-Rolling Stock

In the last month, Amtrak decided not to purchase additional Acela cars, but instead replace the Acela fleet ahead of time, and try to buy trains that aren’t compliant with FRA regulations. More recently, Amtrak and the California HSR Authority decided to bundle their orders together. The latter decision drew plenty of criticism from some good transit advocates, such as Clem Tillier, and even the former decision did. Clem explained,

The whole notion of buying quicker trains for the NEC is ridiculous– the existing Acela Express trains have plenty of oomph (16 kW/tonne) to do anything they need to do. “Lighter” and “faster” isn’t the key to anything on the NEC, and dropping in a higher-performance train will not lead to material trip time improvements. They need to speed up the slow bits first, which isn’t something you do by blowing money on trains.

Clem’s criticism got a fair amount of flak in comments, from me and others, for underestimating how important getting around FRA regulations is. What nobody said in comments, and I only realized after the discussion died out, is how the choice of rolling stock depends heavily on what Amtrak plans to do with infrastructure and service planning in the Northeast. It doesn’t make sense in any case to tether Amtrak’s plans for a corridor that’s in many ways globally unique to the California HSR Authority’s for a fairly standard HSR implementation. But what rolling stock is required, and thus how bad the tethering is, depends on a concrete plan for infrastructure and schedule.

At the highest level, the unique issue with the Northeast Corridor is that significant parts can’t be feasibly upgraded to more than 200-250 km/h or easily bypassed, while others can. This means that there’s a tradeoff between top speed and cant deficiency, and the optimal choice depends on how much investment there is into speeding up segments. In any case it’s critical to improve station throats, interlockings, and railroad junctions, but after the 50 and 100 km/h zones are dealt with, the remaining questions are still nontrivial.

The more money is invested, the less it makes sense to run a 270 mm-cant deficiency, 250 km/h Pendolino, and the more it makes sense to run a Talgo AVRIL or E5/E6, both of which are capable of 350 km/h but only about 180 mm of cant deficiency (or N700-I, which is on paper capable of 330 km/h and about 135 mm and in practice could probably be run at 360 km/h and 175 mm). If there’s one segment that tilts the decision, it’s New Haven-Providence: using the legacy Shore Line, even with heavy upgrades, limits speeds and favors high cant deficiency, while bypassing it on I-95 favors high top speeds. But even the New York-Washington segment of today has a few curves strategically located at the worst locations, which make higher tilt degree a benefit.

In medium-speed territory, the Pendolino versus E5/AVRIL/N700-I decision is the muddiest. I ran rough simulations on an upgraded New Haven Line, with bypasses including those I advocated as a first step but also additional ones in the more difficult Stamford-New Haven segment. A train with E5 cant deficiency and N700-I acceleration did New York-New Haven in 32 minutes, and a Pendolino with all cars powered did it in 30. Neither is a standard trainset, though the former is very close to standard (and the Talgo AVRIL is also quite close). The Pendolino as it is, with about half the cars powered, has low power by HSR standards, and this is a problem for accelerating back from a slow zone at medium speed. With all cars powered (which is feasible, at higher acquisition cost) it’s still far from turbocharged, but can change speed more easily. An off-the-shelf Pendolino would not beat an E5 or AVRIL or N700-I on such a corridor, and of course would not beat it south of New York or north of New Haven.

Since nonstandard trains cost more, it’s important to also decide whether they’re worth the cost. Bearing in mind that Amtrak said a new noncompliant trainset costs $35-55 million, which is above the range for 8-car trains (China pays about $4 million per 350+ km/h car), so it may already be factoring in a premium, paying more for trains is worth it whenever the benefits to passengers are noticeable enough. This, like choosing very high-speed rolling stock rather than a Pendolino, is the most effective at high levels of infrastructure investment. An off-the-shelf Pendolino is good enough for most applications. So is an off-the-shelf N700-I without tilt. It’s okay to be 15 minutes slower than the cutting edge if the cutting edge is too expensive. But the effect of 15 minutes on ridership is more pronounced if it’s the difference between 1:35 and 1:50 than if it’s the difference between 3:00 and 3:15. In addition, the faster the service is, the more revenue each train earns, and this allows spreading the extra acquisition cost among more passengers.

Another factor that’s neglected, at least in public statements, is the service plan. Amtrak service is heavily padded: the fastest northbound Acela is scheduled to do Providence-Boston in 47 minutes, but in the opposite direction it’s 34. Remove the Route 128 stop and this can get close to 30 or even below it. About the fastest trains can go with no schedule padding is 19.25 minutes, and reasonable but not onerous padding raises it to about 20.5. Clearly, more of the difference comes from operating efficiencies than from any speed raising; the Acela already goes 240 km/h between Providence and Boston and already has about 180 mm (7″) cant deficiency.

The limiting factor here is more MBTA ownership and operating culture. A good service plan would make it clear how trains can share the corridor (and the same is true on the New Haven Line, another unduly slowed commuter-owned segment), and because MBTA trains are so slow, any cooperation would involve public statements regarding upgrades to the MBTA. The Acela has level boarding at every stop except New London, which is the easiest to cut out and should be bypassed together with the rest of Shore Line East. It’s the MBTA that has non-level boarding, which remains one of the biggest schedule risks, requiring plenty of recovery time to deal with possible long dwell times coming from above-average crowds.

The problem is that Amtrak has made no statements regarding how to integrate the three legs of the magic triangle. It proposed the Vision plan, which even political transit bloggers like Ben Kabak note the extreme cost of; there’s no funding, and the first segment for which it’s trying to obtain funding, the Gateway Tunnel, is very far from the top priority for speed or even for intercity rail capacity. It now proposes new rolling stock, but is unclear about what the trains are supposed to do except be very fast. (Bundling with a new-build line like California makes sense only if all curves are straightened to a radius of 4+ kilometers, even extremely expensive ones.)

Perhaps it’s a feature of opaque government, that Amtrak refuses to say how much money it needs to meet each timetable and capacity goal. For example, it could say that if Congress gives it $10 billion it could reduce travel time from Washington to Boston from the present 6:45 to 5:45 while also running a peak of 4 long trains per hour at that speed. (I think for $10 billion it’s possible to get down to 3:30 or at worst 4:00, but this is a matter of cost control and not just transparency, though transparency can indirectly lead to better cost control.) This would involve heavy cooperation with the commuter railroads that share its tracks and joint plans, as well as detailed public plans for how much to spend on each segment and for what purpose. This is routine in Swiss rail infrastructure planning, since all major projects have to be approved by referendum, but does not happen in the US. It could be that Amtrak knows what it’s doing but acts like it doesn’t because the structure of government in the US is such that these decisions are made behind closed doors.

But more likely, Amtrak doesn’t know what it’s doing, and is just proposing new initiatives that make it seem forward-looking. Changing FRA rules is an unmixed blessing. Bundling an order with California HSR is not. The fact that Amtrak is doing so, while keeping mum about even what kind of rolling stock it thinks it needs, suggests that it reverses the usual way reform should be: instead of a need for reform producing good results and thence good headlines, a need to get good headlines about reform produces reform ideas that sound good. Some of those good-sounding ideas really are good, but not all are. It’s important for good transit advocates to distinguish the two both privately and publicly.

I feel like in the last two years, we’ve seen important American transit and railroad managers say correct things. Shortly after I started making noise in comments about New York’s outsized subway construction costs, Jay Walder said as much in a report entitled Making Every Dollar Count. Joe Lhota proposed through-running on commuter rail as a solution to improve efficiency. Scott Stringer, too, talked publicly about comparative construction costs, and for all of my criticisms of transit managers who say that, I thought it was enough for him to say that as a political candidate for a medium-term office to deserve my endorsement for the mayoral election, which he unfortunately bowed out of. The FRA proposed to start working on new rules for rolling stock last year. At Amtrak, we’ve just now seen Joseph Boardman propose noncompliant rolling stock. Perhaps I’d be more optimistic if Walder and Lhota had stayed at the MTA for longer to implement their positive reform ideas, instead of using it as a springboard to secure a higher-paying job or run for mayor, but increasingly it looks like the good reform talk is not generally accompanied by good actions.

This is, again, where good transit advocates can have the most influence. We more or less know which reforms are required and which are not. There are disagreements at times (Clem, for one, has much better credentials as a good transit activist than I do), but on most of the agenda items there’s agreement. We already know what details we might want to see from a good plan of action, and the advantage of this is that we can check proposed plans against them. That Amtrak’s gotten so many details wrong suggests that it still doesn’t know what the best practices for rail construction are, even if the basic idea of getting around FRA rules is sound. I wish I didn’t have to say it, but I’ll believe Amtrak’s improved when I see it.

C-Shaped Lines

The ideal rapid transit line looks something like a straight line. It can have deviations, but on a map it will be more or less a line with a definitive direction. Most rapid transit lines are indeed linear, or failing that circular (to provide circumferential service) or L-shaped. In most cities there are just a handful of C-shaped exceptions: London has just one (the Piccadilly Line), Tokyo two (the Marunouchi Line and the Yokosuka-Sobu Line), Paris one (the RER C; Metro 2 and 6 should really count as a circle), Seoul one (Line 6). In contrast, in some cities, such as New York, there are many C-shaped lines. Since most people aren’t traveling in semicircles, it’s worth talking about reasons why cities may build lines that don’t have the most efficient shape.

Reason 1: water

Cities right next to a large body of water may have lines that double back. Chicago has the Blue Line, Toronto has the Yonge-University-Spadina Line, San Francisco has the Daly City-Dublin and Daly City-Fremont BART routes and the T-Third Muni route. If Boston extends the Green Line to Somerville, the Green Line will form a C. Tokyo’s Yokosuka-Sobu through-line is in this category as well. Usually, the transit operator doesn’t expect anyone to take the line for its full length; Toronto is planning a crosstown line bridging the far ends of the C. Such lines are C-shaped because they are really two interlined lines coming from the same direction.

Reason 2: two separate lines joined at the outer end for operational reasons

This can be similar to reason 1 in that nobody is expected to take the line along its full length, but here the joining occurs at the outer end. Singapore’s North-South Line and Vancouver’s Millennium Lines are both examples of this. In Singapore’s case this comes from an international boundary; in Vancouver’s it comes from the need to connect the line to the Expo Line so that trains can go to the maintenance yard, and it proved too hard to connect the lines at the inner end, at Broadway/Commercial. In both examples, what should really be two separate lines are joined by an outer loop that functions as somewhat of a circumferential, but the lines were not planned to provide circumferential service and are not good at connecting to anything other than the two joined lines. (Singapore built a separate circumferential, the Circle Line.) Arguably, the RER C falls into this category too, except the connection between the lines is too inner.

Reason 3: a half-formed circumferential

Hong Kong’s Kwun Tung Line is circumferential in the sense that it doesn’t serve Hong Kong Island, just Kowloon; partially because of water, it is C-shaped. New York’s G route used to be in this category back when it ran to Forest Hills, but in 2001 it was truncated to Court Square and became linear. Other lines in this category are hypothetical: if Paris’s Metro 2 and 6 count as C-shaped, then they fall into this category; Boston’s busiest bus, Line 66, is vaguely C-shaped, acting as a circumferential in the southwestern arc from Harvard to Dudley; and if New York builds Triboro RX then it will fall into this category, too. In this case, usually another reason, or a pure ridership concern, is what prevents completing the line as a full circle, but the line is configured to be useful for interchanges. The Kwun Tung Line is useful for end-to-end trips, but the other hypothetical cases aren’t: Triboro RX would be useful for short trips, but to get from the Bronx to southern Brooklyn, the D is much faster.

Reason 4: administrative boundaries

In regions without much intergovernmental cooperation, administrative boundaries can be as sharp as coastlines. Everything proceeds as in reason #1, but this time the inefficiency is entirely preventable. This specifically affects New York and SEPTA Regional Rail. Morally, New York’s north-south lines should connect the Bronx with Brooklyn and the east-west lines should connect Queens with New Jersey. But because New Jersey is administratively separate, the Queens lines loop back into Brooklyn, creating some awkward shapes on the F, the R, and especially the M both before and after its recent combination with the V. (Some Bronx-Brooklyn lines are also awkwardly shaped, but this is because of water). Likewise, SEPTA Regional Rail barely goes into New Jersey, and only in Trenton; PATCO, serving Camden, is separate, and as a result, while the system had the R# designations, the R5 and R6 were C-shaped and the R7 and R8 self-intersected, helping ensure there was not much suburb-to-suburb ridership.

Reason 5: aberrations

In some cases, such as the Marunouchi Line or Singapore’s self-intersecting Downtown Line, there’s no apparent reason, and in that case the two branches combine to form a C-shaped line for essentially random reasons. Maybe the ideal route through city center is one that connects two branches in the same direction; maybe there is more demand to one direction than to the other.

Of the above five reasons, it is reason 4 that is the most angering. Jersey City and the hill cities to its north have as long a history of ferry-oriented New York suburbanization as Brooklyn. But because of administrative reasons, they never got as much rapid transit, stunting their development. New York’s subway plans never really made any use of the Hudson Tubes, and even the unrealized plans for a North Jersey subway network made surprisingly little use of existing infrastructure. The result: 12 km out of Manhattan, at the same distance as Flushing, New Jersey only has Bogota, Rutherford, and Hackensack; 20 km out, at the same distance as still fairly dense Cambria Heights, New Jersey has Paramus and Montclair.

It’s of course too late for New York to do things right, but for a city just beginning to build a subway network, it’s important to make sure that lines are straight and hit developing suburbs in all directions, so that they can develop as high-density transit-oriented communities, and not as low-density auto-oriented ones.

Asymmetric Mode Choice

In most models I have seen, ridership and mode choice are assumed to be symmetric: if I take the bus to work, I will also take it back home. Of course those models distinguish home from work: if a bus is full inbound in the morning it’s not expected to be full outbound in the morning. But the assumptions are that if the bus is full inbound in the morning, it should be full outbound in the afternoon. To a first-order approximation this is fine, but there are multiple situations in which people can choose differently in each direction. This is less relevant when discussing cars and bikes, because if you use them in one direction you must use them in the other, but it’s relevant to car-share, bike-share, various kinds of buses and trains, walking, and flying.

Most of this post will take the form of anecdotes. I have not seen any model that accounts for these cases, or any discussion elsewhere. The only exception is when large changes in grade are involved: people walk or bike down more easily than up, and this means that in bikeshare systems, the operators sometimes have to tow bikes back to high-elevation neighborhoods because people persistently take them downhill more than uphill. However, in addition to asymmetry caused by physical geography, there’s asymmetry caused by urban layout and transit system layout, as well as asymmetry caused by different characteristics of trips.

Case 1: Frequency Splitting

Consider the above image of a transit network. Point A is a major destination; area D is a neighborhood, and point E is an origin. The thick black line is a rapid transit line, passing through and stopping at B, C, and E. The red and blue lines going east from A are frequent rapid bus lines. The gray line going from A to E is a lower-grade bus line: less frequent, and/or slower.

In this image, traveling between A and either D or E, the frequent buses will be more useful going away from A than toward A. For an A-D trip, if I live in neighborhood D and travel to A, then I need to choose which of the two parallel streets to stand on, whereas going back from A to D, I can stand at the bus terminal and take whichever bus comes first. For an A-E trip, if I live at E and am going to A, then again I need to choose which of the two bus lines to use, that is whether to get off the rapid transit line at B or C, whereas going back this is not an issue. On the margin, I might choose to take the lower-grade but direct bus from E to A but not back.

Neither of the situations is hypothetical. When I went to college at NUS, my situation was similar to the A-E case: while the subway has since reached campus, in the mid-2000s the campus was connected by buses to two separate subway stops, Clementi and Buona Vista, and although some parts were definitely closer to one than to the other, the connecting buses served all parts of campus relevant to me. There was no equivalent of the gray bus, and I’d almost always take a taxi to campus, but usually take transit back. Now that I’m in Vancouver and work at UBC, where bus lines converge from parallel east-west streets, my situation is similar to the A-D case, since I can take Broadway buses as well as 4th Avenue buses; there is no alternative to the buses for me, but if there were, for example bikeshare, or walking if I lived closer to campus, I might well use it.

In those examples the asymmetry is for the most part unavoidable, coming from urban layout. In Vancouver, there are multiple east-west streets on the West Side that deserve frequent bus service. Consolidating everything on one street can come from the opening of a Broadway subway to UBC, but because the asymmetry is a second-order effect, the main argument for the subway has little to do with it.

Case 2: Waiting Facilities

Some bus and train stations are notorious for being unpleasant to wait at. Tel Aviv’s Central Bus Station is dark and labyrinthine. In New York, Penn Station and Port Authority are both unpopular. Many older airports are infamous for their poor amenities and confusing layouts. Because people need to wait going outbound but not inbound, this could affect mode choice.

In Vancouver, UBC has two separate bus loops, one for generally express diesel buses, and one for local electric buses; each loop has buses going on multiple streets, as in the above image. I find the diesel loop noisy and disorienting, and therefore avoid it, waiting at the electric loop or the next stop after the loops. Therefore, I usually take electric buses back home from UBC, while I almost always take diesels toward UBC. I have no direct experience with Kennedy Plaza, but other Providence-based bloggers think little of it; I think it was Jef Nickerson who noted that buses going on the same trunk routes are not co-located there. This could induce a similar asymmetry.

It gets worse when bus stops do not have shelter from the elements. Sheltered stops should be included in any bundle of best industry practices, but when they are present only downtown or at major stations, they can bias me to take the bus in just one direction.

Transit agencies can eliminate this asymmetry by making their facilities better. Usually the cost of shelter, clear signage, a bus bay layout that makes identifying the correct bays easy, and similar improvements is negligible, and the benefits are large. Of course, independently of any asymmetry there is no excuse for not having passable facilities, but in some cases, such as the UBC diesel loop, the situation on the ground is worse than it appears on planning maps and this worsens the passengers’ experience.

Case 3: Stress for Time

For some trips – going to an airport or intercity train or bus station, going to a meeting, going to class, going to a workplace where I need to be there at a specific time – there’s a more pressing need for timeliness in one direction than in the other. This biases in favor of more punctual or faster vehicles, even if they’re more expensive or less pleasant. This manifests itself in airport choice (when flying out of New York, I strongly prefer rail-accessible JFK, while my preference for flying in is much weaker), willingness to transfer to save a few minutes of trip time, willingness to ride a more expensive but faster train (for example, the LIRR versus the E), and bus versus train decisions (trains are almost invariably more reliable, often by a large margin). The few times I used transit to get to NUS, I used the subway, whereas when I went back home I’d often use a trunk bus, which was slower but had a station much closer to where I lived.

In this case, there’s not much the transit agency can do. If the bus versus rail issue is persistent, the best thing that can be done is encourage more mixed-use zoning and more symmetric morning travel demand, so that buses would be used in both peaks and not just in the afternoon peak and vice versa for trains.

Case 4: One-Way Routes

To the extent that the transit activist community has an opinion, it is strongly against one-way pairs, going back at least to Jane Jacobs’ criticism in The Death and Life. I’ve written briefly about them; Jarrett has written more extensively. One more issue is that if a bus route runs one-way on different streets (as a consistent one-way pair as in New York, or in a more complex arrangement as in Tel Aviv and Singapore) and I live closer to one direction than to the other, I might take it in just one direction. In Tel Aviv it was not a major problem because the bus I took to middle school run two-way in the segment relevant to me, but in Singapore it was an issue in both middle school and college: I lived next to a very wide one-way street without nearby crosswalks, and getting to the other direction of the buses required crossing it and walking some extra distance; this helped bias me for taking the bus only in the return direction.

The Effects on the Margins

Since asymmetry is small enough an effect that models can ignore it and still come very close to predicting actual ridership, its effect on transit planning is only on decisions that are very close to begin with.

I believe the most common case is the one in the image. A city that transitions from an idiosyncratic network of infrequent direct buses to a regular frequent grid where passengers are expected to transfer needs to decide which of the infrequent buses to keep. It might even have a few peak-only express buses it is considering keeping. In this case, it’s useful to note in which directions the infrequent or peak-only buses are more likely to get passengers, and potentially have an asymmetric number of trips on those in each direction, recycling the equipment for nearby routes whose asymmetry goes in the other direction.

Construction Costs and Perceptions

While looking for South Korean cost data for a major update of my construction costs posts, I stumbled upon a newspaper article excoriating Seoul’s extravagant construction, comparing it unfavorably with the US. Per Joong-Ang, the US neglect of infrastructure is a form of frugality that South Korea should imitate; the National Mall’s poorly maintained, weedy lawns are treated as something to admire. Moreover, Seoul subway construction is more extravagant than in the Washington Metro:

I got on a train at the Smithsonian Metro station. All the stations there have the same architectural styles. They are the 1976 creation of American architect Harry Weese. High ceilings and open spaces are their trademarks. They are known for their practicality. But they are very modest compared to the subway stations of Seoul. The platforms are dimly lighted. It’s hard to read a book there. The walls are concrete, with none of Korea’s flashing signboards. The architecture is very quiet.

After I returned to Seoul, I got on the subway at Guryong Station in Gangnam District, southern Seoul. Marble proliferates at the entrance. A public table is covered with glass. Every day, about 3,600 people use the station, which cost 55 billion won ($51.2 million) to build.

Of course, in reality, Korean construction costs are a fraction of American ones. Guryong Station is an infill subway station in a dense urban neighborhood, opening about a year after the rest of the Bundang Line; it cost about $75 million in 2010 PPP dollars. The US sometimes builds at-grade infill commuter stations for more than that, and those do not have marble entrances or glass tables (update: New York Avenue in Washington is another example of more expensive US infill, this time an elevated station). Building just the shell of an infill subway station on the 7 extension simultaneously with the rest of the extension was estimated at $500 million. Similarly, the Sin-Bundang Line, a driverless rapid transit line, cost 1,169 billion won, about $1.4 billion, for about 18 km; the line is described as “largely underground,” fully underground, and its city terminus is under a dense secondary CBD. In contrast, in Washington, the suburban Silver Line, with very little tunneling, is $6.8 billion (in 2009-2018 dollars) for 37 km. $183 million per km versus about $80.

There are two takeaway lessons from this. The first is that to gauge whether something is cheap or extravagant we need to know the normal range of costs and compare, rather than looking at the quality of construction. Seoul may build very extravagant-looking stations, but it builds them cheaply for some reason.

The second, more important lesson is that people perceive costs the way they perceive local corruption. The US is indeed the world’s most expensive country to build transit in, which Americans can easily believe since they do not trust their government very much. At the opposite corner, Switzerland is quite cheap: a rejected mountain tunneling project in Neuchatel was CHF 850 million for 17 km, and a recently completed urban tunnel in Lucern was CHF 250 million for 1.32 km; accounting for the Swiss franc’s 87% overvaluation relative to PPP, these are $28 and $121 million per km respectively. And as far as I hear from Swiss commenters, the Swiss are proud of the success of their public transportation system. Indeed, Swiss levels of trust in government and institutions are very high.

In contrast, in cheap countries where people do not trust the government, people do not readily accept that construction costs are low. When I talk to Spaniards who are not railfans, they talk about corrupt and extravagant infrastructure projects, and do not believe that both high-speed rail and subway construction costs in Spain are so low. (It doesn’t help that Barcelona’s L9/10, despite still being about average-cost, went over budget by a factor of over 3.) This is no different from the Joong-Ang attitude toward Korean costs: the government self-evidently doesn’t work, and so a $75 million infill subway station is self-evidently a boondoggle.

The situation in the opposite corner – high trust/low perceptions of corruption, high costs – exists as well, in Singapore. The sixth MRT line, soon to begin construction, is S$18 billion for 30 km; the PPP exchange rate between Singapore and US dollars is about 1:1. The line is automated and fully underground, but about half of it is under very wide arterial roads and portions of it are in undeveloped rather than built-up land; it shouldn’t cost this much. The fifth line, currently under construction, is cheaper, S$12 billion for 40-42 km, but still much more expensive than the non-Anglophone average.

And yet, although Singapore’s not far behind Japan in its construction costs, I doubt Singaporeans are as willing to consider their construction practices expensive as Americans, Britons, and Japanese are. I know for a fact that international commentators who hold Singapore in high regard for its efficient government would not be willing to think of it as an expensive-construction country.

All this makes good transit activism somewhat frustrating, in that people will not usually recognize efficient government in absolute numbers. Percentages, certainly – people understand cost overruns and (much less common) cost underruns, and as we’ve seen in Canada people can compare different technologies. But absolute numbers are not as well-understood, and neither are international comparisons of the same technology, where cost differences revolve around questions of project management, contracting practices, labor rules, and details of geology and surrounding infrastructure; people have only recently begun to think in terms of per-km costs in New York, and in the rest of the US I have not seen such thinking. When a transit agency proposes a project, people automatically think it’s expensive, and some will also say it’s necessary, regardless of whether it actually is either. I don’t think reactions to Second Avenue Subway at $5 billion would be materially different from what they were when Phase 1 alone grew to $5 billion.

The upside is that in budget negotiations, the amounts given to transportation are based on absolute shares of the budget rather than on the needs of specific megaprojects, which means that lower costs would translate to more projects built for the same budget. People might not notice that costs have gone down, and might still complain that every subway line is a boondoggle, but more lines would be built and more people would ride those lines. Just the perception of government competence would not change.

Branching

S-Bahns and similar systems have two defining features. One has been hashed to death on this blog: they reuse legacy rail lines, allowing urban rapid transit to extend arbitrarily deep into suburbia. The other, common also to many other transit technologies, is that they branch extensively, allowing them to run many services on the outer ends, where there’s no demand for rapid transit frequency, while interlining to produce high frequency in the center, where there is.

Since branching is a service planning decision independent of technology, any technology could branch. The branching-friendliest technology is subway-surface: the central subway segment has higher capacity measured in trains per hour than the outer surface segments, and this requires branching. For examples, consider the Boston Green Line, Muni Metro, the Frankfurt U-Bahn, and SEPTA’s Subway-Surface lines. However, even when the entire line is rapid transit, branching is useful to ensure higher service where there is higher demand, and infrastructure improvements will typically focus on boosting capacity in the center. For example, the RER A has moving-block signaling allowing 30 peak-direction trains per hour in the center, but fixed-block signaling on the branches, which do not need such capacity.

Even when rapid transit is built separate from both light rail and mainline rail, branching is useful for lines going into the suburbs or even outer-urban neighborhoods. This is practiced in both New York and London, both of which have extensive branching. Observe further that in both cities, the lines reaching farthest out – the A in the Queens-bound direction and the Metropolitan line in the west – are also the most highly branched.

It’s the opposite situation that is weird. When lines do not branch, there must be a strong outer anchor, or else trains need to run empty outside the center. The alternative is short-turns, and if there’s no space for this, the resulting service patterns can be awkward. Shanghai, which has little branching, runs Line 2 in two segments, a central segment with higher frequency and longer trains and an eastern one with lower frequency and shorter trains; trains do not run through. Beijing has a similar awkwardness with the split between Line 1 and the Batong Line, and Toronto has a split between the Bloor-Danforth line and the technologically incompatible Scarborough rapid transit. (The Sheppard line suffers from the same problem today, but it has the excuse that it was planned to continue west to the Spadina subway rather than stub-ending at Yonge.) Paris has little branching on the Métro as well, but the Metro only serves inner parts of the metro area, many lines have strong outer anchors (for example, La Défense on Line 1), and two others providing some of the farthest-out service branch. The RER branches much more heavily, as befits a suburban system. Tokyo has little branching on the subway proper, but the subway is for the most part inner-urban, and lines continue to the suburbs along commuter lines, which do branch.

In North America, this configuration has been common across a variety of new-build systems, especially ones that should have been S-Bahns. BART does this the most extensively, but the Washington Metro is also highly branched for its size, MARTA branches, the light rail systems branch once more than one line is built, and so on. BART in particular imitated the service planning aspect of commuter rail perfectly, and is an S-Bahn in all but the cost of extending the system further.

The problem with any branching is that it reduces frequency on the branches, potentially scaring away ridership. When a single rapid transit line splits in two it’s rarely a problem, and when city-center service splits into suburban services even more is easy to justify. I think the main issue in urban or inner-suburban cases is that with typical rapid transit frequencies (3-minute peak service or slightly better, a peak-to-base ratio of 2:1 or somewhat less) the trunk has about 5-minute off-peak service, and if it splits into two branches, this means 10-minute service on the branches. If the branching occurs early enough that dense neighborhoods with short-distance travel demand are on branches, it may be too little. In addition, if one branch has much more demand than the other, then it’s usually hard to match frequency on each branch to demand, since it requires trains to be unevenly spaced.

The issue is that branch frequency, 10-15 minutes, is in the transition zone between urban show-up-and-go frequency, where schedules do not matter, and suburban frequency, where they do. It’s perhaps less relevant in small cities with small enough transit systems that even 10-minute service is considered very good, but in large cities, people expect more, creating somewhat of an inner-urban metro envy effect.

That said, 10-minute suburban and outer-urban service can be done clockface, making the average wait much smaller. It is done on the RER A in the midday off-peak, with three 10-minute branches, and could be done with two 10-minute branches quite easily. Likewise, it could be done for 15-minute branches (the RER B already does this); the two A branches in New York have close to 15-minute frequency each, and if New York City Transit’s service planning considered it as a factor instead of focusing more on headway management it could ensure predictable schedules at Ozone Park and the Rockaways.

Transit and Place

There is a large class of transit supporters who think that every right-of-way that can be used for transit should be preserved for this purpose, even if it is not very useful. A few overzealous railfans on the message boards opposed the opening of the High Line park and wanted the viaducts to be used for an extension of the 7 train. This is extreme and nowadays the transit activists I know support the High Line while opposing schemes to recreate it in an inferior context. But even serious bloggers like Cap’n Transit, Ben Kabak, and John Morris are opposing plans to create a Low Line out of the abandoned trolley terminal at the Essex/Delancey subway stop, on the grounds that it could be useful for transit one day.

Now, it’s possible that the Low Line idea is bad because people would not want to go to an underground park. But it’s not a problem for transit; the Williamsburg Bridge doesn’t need trolleys since it has a subway running on (and because the bridge is high there is no way a bus could cross it without passing within two blocks of Marcy, the subway stop at the Brooklyn end of the bridge). The lines running on it are in fact underused: as can be seen on PDF-pages 65-73 of the latest Hub Bound Travel Data report, peak-hour traffic on the J/M/Z entering the Manhattan core was one of the lower in the system as of 2010 – higher than the bottom two track pairs (8th Avenue local and Montague) but in a near-tie for third lowest with several others. So there’s not much use for the trolley terminal as a modern Williamsburg Bridge bus (or trolley) terminal.

But what is more important than just the Low Line is place. To succeed, transit needs not only to exist, which it already does in the area in question, but also to have places to connect to. If for some reason the trolley terminal would need to be demolished to build room for foundations for several skyscrapers, it would be an unambiguous win for transit, since it would create more destinations for people to take the existing J/M/Z and F trains to. The surrounding neighborhood might disagree regarding the implications for urbanism, though I’d argue that Midtown-like skyscrapers would be better-integrated into the streetscape than the projects east and south of the station. If the Low Line succeeds as a park, it will be similar: not in the sense of providing jobs for tens of thousands of people, but in the sense of creating a place for people to go to. (In fact, a park has less peaky demand than offices, so it could be better for subway finances even at relatively low levels of usage.)

Last year, I brought up the question of the infrastructure’s highest value mainly as a way of deciding which kind of service (regional, intercity, etc.) should get first priority on any given rail line, but the same is true about transit versus place. In an area with enough transit and not enough place, it’s more important to create more development, for both good urbanism and more successful transit.

This does not mean every proposal to turn a rail right-of-way into a park is good. Despite my skepticism that the Rockaway Cutoff can be a successful rail line, I’m even more skeptical about its value as a park; it’s not in an area that can ever draw many people, since the density (of both residences and jobs) is not high by New York standards and it is far from other destinations that could draw people from outside the nearby neighborhoods. However, in areas that are lacking in good parks, or could use new development, it is better to concentrate on creating place.

For examples of this elsewhere, consider the railyards in Long Island City, Hoboken, and Sunnyside. Two of my earliest posts proposed to build a regional rail station in Sunnyside and then develop the area around it with air rights over the railyard; this is what should be done in an area that needs both transit and place. But in Hoboken and Long Island City, there’s ample transit, and the only use of the railyards is to park trains that can’t do to Manhattan because of lack of electrification or lack of capacity in the approach tunnels. Since parking trains is an inefficient use of space, and both areas have good connections to Manhattan by subway or PATH, there should be plans to remove the railyards and redevelop them to create more place, leaving just enough rail infrastructure to run through-trains, to be parked in lower-value areas. This development can be either parkland or buildings, depending on what is in demand in the area. Based purely on Google Earth tourism, I believe Hoboken does not need additional parks and so development there should be just a new secondary CBD on top of the PATH station, while Sunnyside and Long Island do, and so development there should include parks as well as high-density office and residential construction.

Instead of worrying about turning unused and for the most part unusable transit infrastructure into place, good transit activists should focus on preserving infrastructure that could potentially be used. In the New York area, probably the most useful piece of infrastructure that isn’t currently used is the Bergen Arches, allowing the Erie lines to enter Jersey City at Pavonia/Newport, a more central location than Hoboken; this is one of four options for a location for a new regional rail tunnel from New Jersey to Lower Manhattan, and is arguably the best option for an integrated regional rail network.

In the 1990s there were plans to reuse the Bergen Arches for a roadway, since modified to include both a road option and a rail option, and in 2011 the Christie administration allocated some money to further studies; an analysis from 2004 scored various road and transit options, not including a regional rail network, and gave the highest score to a roadway with a single high-occupancy vehicle and bus lane per direction. (A trail got the second lowest score, after no-build.) Since Jersey City (and the entire region) needs more transit from the north and west, while further formation of place will and should cluster around the waterfront, it’s important to fight any plan to give the Bergen Arches to a non-railroad use unless and until a regional rail plan is formulated that places the New Jersy-Lower Manhattan tunnel at another location.

In contrast, the Low Line should not be a priority. On the contrary, if the park plan is even partially sound, or the place could be reused as another place if the park idea fails, then good transit advocates should support the idea, since it’d be good urbanism. With a few exceptions, good transit requires good urbanism and vice versa.

How Residential Blocks Act As Barriers

Two weeks ago, I found a board game store in Vancouver, and through it a variety of gaming events. The store is located about five blocks from my apartment, and I first saw it from a bus nearly two months after moving to Vancouver. It’s in the same neighborhood; to get from my apartment to the store requires walking on ordinary city streets with sufficient sidewalks and room to cross. However, those streets are residential, and so I have no reason to walk in that direction. It creates a split in what is formally the same neighborhood.

In my section of Vancouver, the two major throughfares are 4th Avenue and Broadway (9th). There is some retail elsewhere (e.g. on Cornwall, which is -1st, and even more so on Granville Island), but it’s not the continuous commercial development on the two major avenues. Even if it’s as big as Granville Island, it requires me to go specifically to it, whereas on 4th I can go until I see something I am interested in. Before I had wi-fi installed in my apartment, which is on 1st but which I got to by taking a 4th Avenue bus, I walked on 4th until I saw a cafe with free wi-fi and sat there.

This continuous retail ends roughly at the cross street I live on. It extends far east: on Broadway it’s to and beyond Cambie, but to the west it ends just west of Arbutus; on 4th, it extends east to about the Granville Bridge. As I said in my first post about Vancouver, the development on Broadway is fairly spiky, with peaks around Cambie, Granville, and Arbutus, but there’s also a base of 1- to 2-story retail. On 4th, the development is just continuous 1- to 2-story retail. The next major street west of Arbutus, Macdonald, has retail clusters at both Broadway and 4th, but on both avenues there’s a two-block residential gap between the Arbutus side and the Macdonald side. Living on the Arbutus side, I learned early that if I walk east there are cafes, stores, and restaurants immediately, and if I walk west there aren’t. The result is that even though in principle Macdonald is in my neighborhood whereas anything more than three blocks east of Arbutus isn’t, I go this far east of Arbutus much more than I go to Macdonald.

The main advantage of grid street networks over the gridless network of e.g. Providence is that they can provide continuous development, making it easy for people to spontaneously walk in all directions. In Providence spontaneity was provided only by the fact that I knew where the various retail clusters on the East Side were; in reality I would almost always go to Thayer rather than Wickenden or Wayland Square. In gridded cities neighborhoods are less formally defined around one center, but instead evolve more organically, since the center can shift over time and the street network doesn’t distinguish it from the boundary with the next neighborhood over.

On a broader level, this spontaneity is a good way to promote more access. If I can walk to interesting retail in more directions, there’s a higher chance I’ll find something that suits my interests, just as the gaming store does. It provides the same benefits as an increase in density or in travel speed, in this case specialization of retail.

Intercity Buses and Trains

In the three countries with the longest and traditionally largest HSR networks – Japan, Germany, and France – there is no large intercity bus network, with government regulations against the development of one. The US and Canada are in somewhat of the opposite situation – intercity buses are legal, but intercity trains are subject to a variety of regulations and operating practices raising operating costs so much that outside the thickest corridors they might as well be illegal. The best situation is in South Korea, which has well-developed networks of both buses and trains; the result is that on the Seoul-Daegu and Seoul-Busan city pairs, buses have 7-8% of the market and trains 67%.

On top of that, the express buses in North America do not get very high mode share. I’ve seen no reliable numbers, but when I looked at Megabus and Bolt schedules on the largest city pairs, the two carriers combined were about even with Amtrak, whose mode share on the entire NEC is 6% according to the Vision.

So why is Cap’n Transit suddenly telling us to love the bus (though he rejects the loaded term “love the bus”) and advocate for more investment into bus stations at various locations around the metro area? Doctrinaire libertarians have the excuse that the kind of regulations they are used to thinking of are the French regulations against domestic competition with rail and not the FRA’s safety rules. But the Cap’n of course knows exactly how pernicious FRA rules are. Since he thinks in terms of activist energy as the primary resource to manage, and not the government’s budget, this could be taken as a desperation at any attempt to reform Amtrak and the FRA.

But more likely, this comes from the fact that many intercity bus supporters fought (and lost) regulations against curbside pickups, which are the way Megabus, Bolt, and others could serve New York without paying for space at Port Authority, imitating the practices of the older Chinatown buses.

The immediate trigger for thinking where to place bus stops then is the impending loss of curbside space. Since buses are in many ways intermediate between cars and trains in terms of capacity and the point-to-point versus hub-and-spoke tradeoff, a bus expansion then has to mean finding more and more places to pick up. A legacy train station will run out of running line capacity long before it runs out of station track capacity, but a curbside bus stop uses valuable urban space and a bus station can and does run out of space.

And this is where buses stop being too useful. Frequency is freedom. Because the bus operators compete with one another, passengers need to be ticketed on a specific company, and that already cuts into frequency. On top of that, unlike trains, buses have a very large stop penalty, since they need to get off the highway and into the city. New York-Washington trains make intermediate stops in Philadelphia; express buses don’t. Even with dominant CBD stations, the frequency on the buses in the Northeast isn’t great: from New York, Bolt offers half-hourly service from to Philadelphia, hourly service to Boston, and less than hourly service to each of Baltimore and Washington, and all four city pairs have one dominant stop pair; Megabus frequency is hourly to Boston and hourly with a half-hourly peak to the other three.

Adding more stops means diluting this less-than-great frequency even further. It would work if bus stops were consolidated and people could buy one ticket good on any company, but the business model that has reduced ticket prices is probably not compatible with such cooperation. It would also work if the market share were 67%, but it isn’t and never will be.

The other problem is that people have not just origins but also destinations – and those destinations cluster in the CBDs, and the more the passenger is willing to pay, the likelier it is they’ll be traveling to the CBD. A train run from Woodside or Newark to New York will be full in one direction and empty in the other; the reason those trains can make money (they don’t in New York, but do in Tokyo, which is as CBD-dominant) is that they’re so full in the peak direction it makes up for lower reverse-peak occupancy. For intercity travel, this is harder. High-speed rail can make a profit on these asymmetric intercity runs because it’s so fast that it can cut costs that depend on travel time and not distance, such as operator wages, dispatcher wages, and some train maintenance. Buses don’t have that luxury, and need to be full in both directions, which favors CBD-to-CBD runs, or runs between neighborhoods that are likely to be destinations as well as origins (such as Chinatown-to-Chinatown runs).

Trains are unique among common-carrier transportation modes in that service uses corridors and not points. They are similar to cars this way: I-95 and the Northeast Corridor serve many overlapping city pairs. Bus services do not have this advantage, because the nature of an expressway network is such that they have to deviate to make a station stop, and in the largest cities this deviation is considerable; it can take an hour for a bus to navigate New York’s streets. This makes them more point-to-point, like planes, and on a corridor with four large cities on one line, this is much less efficient.

In general, I think a lot of the pro-bus attitude among liberals and general transit activists (as opposed to libertarians, who I will address in a future post) amounts to defeatism. We will never be able to improve government to the point that trains have high mode share, so let’s downgrade service. We will never be like France or Germany or Switzerland or Japan, so let’s import practices from China and Scotland.

Transit activists for the most part have not only political but also personal preferences for travel by transit. When I visited Buffalo, I took the Empire Service instead of flying. This creates a skewed impression for what’s good; to me, the Empire Service is a semi-useful service, even as to the average traveler it might as well not be there. If the existing service is straightforwardly a worse version of good service – such as a commuter train that should run faster and more frequently, or an intercity train that should be HSR – this is not a problem. But if it is different – such as a bus where a train is more appropriate, a light rail or dedicated subway line where an S-Bahn is appropriate, or even a rapid transit line in the wrong type of neighborhood – then the activism can be in a wrong direction.

The problem is that the 80-90% of travelers who drive are not currently agitating for the mode of transit most likely to get them to switch. Like transit users, they have at least to some extent made their peace with their current mode’s deficiency, and if anything they will demand more highway expansions even on corridors where transit is much more useful for the same cost. But we can take a step back and look at case studies from peer first-world countries and see that buses have mode shares in the single digits while trains can dominate corridors in the Northeast Corridor distance range.