Note: I am going to take some suggestions for post topics in the future. This post comes from a Twitter poll I ran the day before yesterday.
The Yamanote Line in Tokyo is a ring. Trains go around the ring as on any other circular rail line. However, the line is not truly circumferential, since it serves as a north-south trunk through Central Tokyo. In that way, it contrasts with fully circumferential rings, such as the Moscow Circle Line, Seoul Metro Line 2 (see update below), and the under-construction Paris Metro Line 15. It’s really a hybrid of radial and circumferential transit, despite the on-paper circular layout. In previous posts I’ve attacked one kind of mixed line and given criteria for when another kind of mixed line can work. In this post, I’m going to discuss the kind of mixed line Yamanote is: why it works, and in what circumstances other cities can replicate it.
Consider the following diagram:
The red and blue lines are radial. The other three are hybrids. The yellow line is radial, mostly, but skirts city center and acts as a circumferential to its west; this kind of hybrid is nearly always a bad idea. The pink line is radial, but at the eastern end bends to act as a circumferential at the eastern end; this kind of hybrid is uncommon but can work in special cases, for example if Second Avenue Subway in New York is extended west under 125th Street. The green line is a Yamanote-style ring, offering radial service through city center but also circumferential service to the south and west.
On this map, the green line ensures there is circumferential service connecting what are hopefully the major nodes just west and south of city center. It doesn’t do anything for areas north and east of it. This means that this line works better if there is inherently more demand to the west and south than to the east and north. In Tokyo, this is indeed the case: the Yamanote ring offers north-south circumferential service west of Central Tokyo, through what are now the high-density secondary business districts of Ikebukuro, Shinjuku, and Shibuya. East of Central Tokyo, the only really compelling destinations, judging by subway ridership, are Oshiage and Asakusa, and neither is as big as Ikebukuro, Shinjuku, or Shibuya. Toyosu has high subway ridership, but is close enough to the water that it’s hard to build a circumferential through it.
Such a mixed line also becomes more useful if the radial component is better. The radial line can’t extend very far out, since the line needs to form a ring, so it should connect to very high-density neighborhoods just a few stops outside city center, or else provide additional service on an overloaded radial trunk. The Yamanote Line benefits from looking less like a perfect circle and more like upside-down egg, with two elongated north-south legs and two short (one very short) east-west legs; it extends its radial segment slightly farther out than it would otherwise be. In Tokyo, of course, all rail lines serving the center are beyond capacity, so the Yamanote Line’s extra two tracks certainly help; in fact, the two radial lines going north and south of Tokyo Station on parallel tracks, the Tohoku and Tokaido Lines, are two of the three most overcrowded in the city. (The third is the Chuo Line.) There’s even a dedicated local line, Keihin-Tohoku, covering the inner segments of both lines, making the same stops as Yamanote where they are parallel, in addition to the more express, longer-distance Tokaido and Tohoku Main Line trains.
Finally, there should not be radials that miss the mixed line; this is always a danger with subway lines that are neither pure radials nor pure circumferentials. Yamanote avoids this problem because it’s so close to the water at Shimbashi that the north-south subway lines all curve to the west as they go south, intersecting the ring. It’s actually the east-west lines that cross the Yamanote Line without transfers, like Tozai and Hanzomon; the north-south lines intersect the line with transfers.
The obvious caveat here is that while the Yamanote Line functions very well today, historically it did not originate as a circumferential in an area that needed extra service. It was built as a bypass around Central Tokyo, connecting the Tokaido and Tohoku Line at a time when Tokaido still terminated at Shimbashi and Tohoku at Ueno. Tokyo Station only opened 30 years later, and the ring was only completed another 10 years after that. Shinjuku only grew in the first place as the junction between the Yamanote and Chuo Lines, and Ikebukuro and Shibuya grew as the terminals of interwar private suburban railways. When the line opened, in 1885, Tokyo had 1.1 million people; today, the city proper has 9.5 million and the metro area has 38 million. The early rail lines shaped the city as much as it shaped them.
Nonetheless, with the economic geography of Tokyo today, the Yamanote Line works. Even though the history is different, it’s a useful tool for mature cities seeking to build up their rail networks. Provided the principles that make for the Yamanote Line’s success apply – stronger demand for circumferential service on one side of city center than on the others, demand for supplemental inner radial service, and good connections to other lines – this layout can succeed elsewhere.
Waterfront cities should take especial note, since they naturally have one side that potentially has high travel demand and one side that has fish. In those cities, there may be value in running the radial closest to the shoreline in a ring with an inland line.
This does not mean that every waterfront city should consider such a line. On the contrary: non-examples outnumber examples.
In Toronto, using two mainline tracks and connecting them to a ring to provide subway relief could have worked, but there are no good north-south corridors for such a ring (especially on the west), and the only good east-west corridor is Eglinton, which is being built incompatible with mainline rail (and has too much independent value to be closed down and replaced with a mainline link).
In Chicago, the grid makes it hard to branch lines properly: for example, a ring leaving the Red Line heading west at Belmont would necessary have to branch before Belmont Station, cutting frequency to the busiest station in the area. Plans for a circle line from last decade also faced limited demand along individual segments, such as the north-south segment of the Pink Line parallel to Ashland; ultimately, the planned line had too small a radius, with a circumference of 16 km, compared with 34.5 for Yamanote.
In Tel Aviv, there just isn’t any compelling north-south corridor outside the center. There are some strong destinations just east of Ayalon, like the Diamond Exchange and HaTikva, but those are already served by mainline rail. Beyond that, the next batch of strong destinations, just past Highway 4, is so far from Central Tel Aviv that the line would really be two radials connected by a short circumferential, more the London Circle Line when it was a full circle than the Yamanote Line, which is just one radial.
So where would a Yamanote-style circle be useful outside Tokyo? There are semi-plausible examples in New York and Boston.
In New York, it’s at the very least plausible to cut the G off the South Brooklyn Line, and have it enter Manhattan via the Rutgers Street Tunnel, as a branch of the F, replacing the current M train. There is no track connection enabling such service, but it could be constructed just west of Hoyt-Schermerhorn; consult Vanshnookraggen’s new track map. This new G still shouldn’t form a perfect circle (there’s far too much radial demand along the Queens Boulevard Line), but there are plausible arguments why it should, with a short tunnel just west of Court Square: namely, it would provide a faster way into Midtown from Williamsburg and Greenpoint than the overcrowded L.
In Boston, there is a circumferential alignment, from Harvard to JFK-UMass via Brookline, that can get a subway, in what was called the Urban Ring project before it was downgraded to buses. Two of the busiest buses in the region, the 1 and 66, go along or near the route. An extension from Harvard east into Sullivan and Charlestown is pretty straightforward, too. Beyond Charlestown, there are three options, all with costs and benefits: keep the line a semicricle, complete the circle via East Boston and the airport, and complete the circle via the North End and Aquarium. The second option is a pure circumferential, in which South Boston, lying between East Boston and JFK-UMass, would get better service north and south than west to Downtown. The third option cuts off East Boston, the lowest-ridership of the radial legs of the subway, and offers a way into the center from South Boston and Charlestown.
Of note, neither New York nor Boston is a clear example of good use of the Yamanote-style ring. This style of mixed line is rare, depending on the existence of unusually strong circumferential demand on just one side (west in Boston, east in New York), and on the water making it hard to build regular circles. It’s an edge case; but good transit planning revolves around understanding when a city’s circumstances produce an edge case, in which the simplest principles of transit planning (“every subway line should be radial or circumferential”) do not apply.
Update 5/16: commenter Threestationsquare reminds me that Seoul Metro Line 2 is the same kind of ring as Yamanote. The north leg passes through City Hall, near the northern end of the Seoul CBD, providing radial east-west service. The south leg serves a busy secondary commercial core in Gangnam, Tehran Avenue; Gangnam Station itself is the busiest in Seoul, and has sprouted a large secondary CBD.
In 2011, Clem Tillier and Richard Mlynarik put out sample schedules for modernized Caltrain service, with an applet anyone could use to construct their own timetables. I played with it, and one of the schedules I made, a trollish one, had room for local and express regional trains, but not intercity trains; intercity trains would be slotted with express regionals, and make the same stops. This was a curious exercise: intercity trains would be high-speed rail, which should not slow down to make every express regional stop. But more recently, as I’ve worked on schedules for Boston and New York, I’ve realized that when the regional trains are fast, there is merit to slotting legacy (but not high-speed) intercity trains together with them.
The origin of this pattern is the problem of slotting trains on busy railroads. There are many lines that are not really at capacity, but cannot easily combine trains that run at different speeds. One solution to the problem is to build extra tracks and give the intercity trains a dedicated pathway. This works when there is heavy intercity traffic as well as heavy regional traffic, but four-tracking a long line is expensive; Caltrain and California HSR ended up rejecting full four-tracking.
Another solution, favored for Caltrain today instead of full four-tracking, is timed overtakes. I have argued in its favor for Boston-Providence and Trenton-Stamford for high-speed rail, but it requires more timetable discipline and makes it easier for delays on one train to propagate to other trains. It should be reserved for the busiest lines, where there is still not enough traffic to justify long segments with additional tracks (that would be four tracking Boston-Providence and six-tracking Stamford-New Rochelle and Rahway-New Brunswick), but there is enough to justify doing what is required to run trains on a tight overtake schedule. It is especially useful for high-speed trains, which tend to be the most punctual, since they use the most reliable equipment and have few stops.
But on lower-ridership intercity routes, the best solution may be to force them to slow down to the speed of the fastest regional train that uses the line. On the timetable, the intercity train is treated as a regional train that goes beyond the usual outer terminal. This option is the cheapest, since no additional infrastructure is required. It also boosts frequency, relative to any solution in which the intercity train does not make regional stops: since the intercity train is using up slots, it might as well provide some local frequency when necessary. These two benefits together suggest a list of guidelines for when this pattern is the most useful:
- The intercity line shouldn’t be so busy that a slowdown of 10 or 15 minutes makes a big difference to ridership relative to the cost of overtakes. Nor should it be especially fast.
- The regional line, or the most express pattern on the regional line if it has its own local and express trains, should have wide stop spacing, such that the speed benefit of running nonstop is reduced.
- The regional line should connect long-distance destinations in their own right, and not just suburbs, so that there is some merit to connecting them to the intercity line. These destinations may include secondary cities, airports, and universities (but airports would probably be intercity stops under any pattern).
- The regional and intercity lines should be compatible in equipment, which in practice means either both should run EMUs or both should run DMUs (locomotives are obsolete for passenger services).
Both Switzerland and Japan employ this method. In Switzerland, the fastest intercity trains in the Zurich/Basel/Bern triangle run nonstop. But intercity trains going north or east of Zurich stop at the airport, interlining with regional trains to create a clockface pattern of trains going nonstop between the airport and the city.
In Japan, high-speed services run on their own dedicated tracks, with separate track gauge from the legacy network, but legacy intercity services are integrated with express regional trains. An intercity trip out of Tokyo on the Chuo Line starts out as a regular express commuter train, making the same stops as the fastest express trains: starting from Shinjuku, the Azusa sometimes stops at Mitaka, skips Kokubunji, and stops at Tachikawa and Hachijoji. Beyond Hachijoji, some trains make regional express stops, others run nonstop to well beyond the Tokyo commuter belt. On the Tokaido Line, the intercity trains (the Odoriko) skip stops that every regional train makes, but they still stop at Shinagawa and Yokohama, and sometimes in some Yokohama-area suburbs.
In North America, there are opportunities to use this scheduling pattern in New York, Boston, and Toronto; arguably some shorter-range intercity lines out of Philadelphia and Chicago, such as to Reading and Rockford, would also count, but right now no service runs to these cities.
In Toronto, GO Transit already runs service to Kitchener, 100 kilometers from Union Station. For reasons I don’t understand, service to Kitchener (and to Hamilton, a secondary industrial city 60 km from Toronto) is only offered at rush hour; in the off-peak, commuter trains only run closer in, even though usually intercity lines are less peaky than commuter lines. There is also seasonal service to Niagara Falls, 130 km from Toronto. As Metrolinx electrifies the network, higher frequency is likely, at least to Hamilton, and these trains will then become intercity trains running on a regional schedule. This works because GO Transit has very wide stop spacing, even with proposed infill stops. Niagara Falls is a leisure destination, with visitors from all over the Greater Toronto Area and not just from Downtown, so the extra stops in the Toronto suburbs are justified. Right now, Niagara Falls trains make limited stops, about the same number in the built-up area as the express trains to Hamilton but on a different pattern.
There are no infill stops planned on Lakeshore West, the commuter line to Hamilton and Niagara Falls. It is likely that future electrification and fare integration will create demand for some, slowing down trains. The line has three to four tracks (with a right-of-way wide enough for four) and is perfectly straight, so as demand grows with Toronto’s in-progress RER plan, there may be justification for local and express trains; express trains would make somewhat fewer stops than trains do today, local trains would stop every 1-2 km in the city and in Mississauga. Intercity trains could then easily fit into the express commuter slots; potential destinations include not just Hamilton and Niagara Falls, but also London.
This is unfriendly to high-speed trains. However, Canada is not building high-speed rail anytime soon; if it were, it would connect Toronto with Montreal, using Lakeshore East, and not with points west, i.e. London and Windsor. London and Windsor are small, and a high-speed connection to Toronto would be financially marginal, even with potential onward connections to Detroit and Chicago. A Toronto-Niagara Falls-Buffalo-New York route is more promising, but dicey as well. Probably the best compromise in such case is to run trains on a four-tracked Lakeshore West line at 250 km/h; the speed difference with nonstop trains running at 160 km/h allows 15-minute frequency on each pattern without overtakes, and almost allows 12 minutes. Alternatively, express trains could use the local tracks to make stops, as I’ve recommended for some difficult mixtures of local, express, and intercity trains on the Northeast Corridor in New York.
In Boston, the Northeast Corridor is of course too important as an intercity line to be slowed down by regional trains. Thus, even though in other respects it would be great for merging intercity and regional service, in practice, overtakes or four tracks are required.
However, all other intercity-range commuter lines in Boston should consider running as regular commuter trains (electrified, of course) once they enter MBTA territory. These include potential trains to Hyannis on Cape Cod, 128 km from South Station; Manchester, 91 km from North Station; and Springfield, 158 km from South Station; as well as existing trains to Portland, 187 km from North Station. Hyannis, Manchester, and Portland all feed into very fast regional lines: my sample schedule and map have trains to Hyannis averaging 107 km/h and trains to Manchester averaging 97 km/h. Trains to Haverhill, the farthest point on the line to Portland with any Boston-bound commuter traffic, average 88 km/h.
Springfield is more difficult. The Worcester Line is slower, partly because of curves, partly because of very tight stop spacing in the core built-up area. Once under-construction infill is complete, Auburndale, 17 km out of South Station, will be the 7th station out, and another infill station (Newton Corner) is perennially planned; my schedule assumes 3 additional stations, making Auburndale the 11th station out. On the line to Hyannis, the 11th station out, Buzzards Bay, is at the Cape Cod Canal, 88 km out. There is room for four tracks for a short segment in Allston, but in the suburbs there is no room until past Auburndale, which constrains any future high-speed rail plan to Albany. Low-speed intercity trains would have to slow down to match commuter rail speed, because the alternative is to run commuter rail too infrequently for the needs of the line. Average speed from South Station to Worcester is 70 km/h, even with express diesels today, so it’s not awful, but here, slowing down intercity trains is a less bad option rather than a good one.
In New York, as in Boston, intercity trains fit in regional slots away from the Northeast Corridor. Already today there are intercity trains running on the LIRR, to the eastern edge of Long Island, much too distant from the city for commuter traffic. Those trains run nonstop or almost nonstop, and are infrequent; if the entire LIRR were electrified, and express trains were eliminated, locals could match the express speed today thanks to reduced schedule padding, and then some trains could continue to Greenport and Montauk providing perhaps hourly service. Service to Danbury and Waterbury on Metro-North is of similar characteristics.
The New Jersey end is more interesting. Right now, there is no significant intercity service there, unless you count the Port Jervis Line. However, New Jersey Transit is currently restoring service on the Lackawanna Cutoff as far as Andover, and there remain proposals to run trains farther, to Delaware Water Gap and Scranton. Those would be regular express diesel trains on the Morris and Essex Lines, presumably stopping not just at Hoboken but also at important intermediate stations like Newark Broad Street, Summit, and Morristown.
If service were electrified, those trains could run, again on the same pattern as the fastest trains that can fit the Morristown Line (where I don’t think there should be any express trains), going to New York and onward to whichever destination is paired with the shorter-range commuter trains on the line. The same is true of other potential extensions, such as to Allentown, or, the favorite of Adirondacker in comments, a line to West Trenton and onward to Philadelphia via the West Trenton SEPTA line. There’s not much development between the edge of the built-up suburban area at Raritan and either Allentown or the Philadelphia suburbs; but intercity trains, averaging around 90 km/h, could succeed in connecting New York with Allentown or with the northern suburbs of Philadelphia, where a direct train doing the trip in an hour and a half would be competitive with a train down to 30th Street Station with a high-speed rail connection.
The characteristics of intercity lines that favor such integration with regional lines vary. In all cases, these are not the most important intercity lines, or else they would get dedicated tracks, or overtakes prioritizing their speed over that of commuter trains. Beyond that, it depends on the details of intercity and regional demand. But by default, if an intercity line is relatively short (say, under 200 km), and not so high-demand that 200+ km/h top speeds would be useful, then planners should attempt to treat it as a regional line that continues beyond the usual terminus. Alternatively, the commuter line could be thought of as a short-turning version of the intercity line. Planners and good transit advocates should include this kind of timetabling in their toolbox for constructing integrated regional rail schedules.
A recent discussion on Twitter about the through-running plan offered by ReThinkNYC got me thinking about an aspect American through-running crayonistas neglect on their maps: the branch-to-trunk ratio. It’s so easy to draw many branches converging on one trunk: crayon depicts a map and not a schedule, so the effects on branch frequency and reliability are hard to see.
In contrast with crayonista practice, let us look at the branch-to-trunk ratio on existing through-running commuter networks around the developed world:
The RER has 5 lines, of which 4 are double-ended and 1 (the E) is single-ended, terminating in the Paris CBD awaiting an extension to the other side. They have the following numbers of branches:
RER A: 3 western branches, 2 eastern branches.
RER B: 2 northern branches, 2 southern branches; on both sides, one of the two branches gets 2/3 of off-peak traffic, with half the trains running local and half running express.
RER C: 3 western branches, 4 eastern branches; one of the eastern branches, which loops around as a circumferential to Versailles, is planned to be closed and downgraded to a tram-train.
RER D: 1 northern branch, 3 southern branches; the map depicts 4 southern branches, but only 3 run through, and the fourth terminates at either Juvisy or Gare de Lyon.
RER E: 2 eastern branches; the ongoing western extension does not branch, but is only planned to run 6 trains per hour at the peak, so some branching may happen in the future.
The RER B and D share tracks between Chatelet-Les Halles and Gare du Nord, but do not share station platforms.
Thameslink has 3 southern branches. To the north it doesn’t currently branch, but there is ongoing construction connecting it to more mainlines, and next year it will gain 2 new northern branches, for a total of 3. Crossrail will have 2 eastern branches and 2 western branches. Crossrail 2 is currently planned to have 3 northern branches and 4 southern branches.
Berlin has 2 radial trunk routes: the east-west Stadtbahn, and the North-South Tunnel. The Stadtbahn has three S-Bahn routes: S5, S7, S75. The North-South Tunnel also has three: S1, S2, S25. Each of these individual routes combines one branch on each side, except the S75, which short-turns and doesn’t go all the way to the west.
Berlin also has the Ringbahn. The Ringbahn’s situation is more delicate: S41 and S42 run the entire ring (one clockwise, one counterclockwise), but many routes run on subsegments of the ring, with extensive reverse-branching. At two points, three services in addition to the core S41-42 use the Ringbahn: S45, S46, and S47 on the south, and S8, S85, and S9 on the east.
There is a two-track central tunnel, combining seven distinct branches (S1-8, omitting S5). S1 and S2 further branch in two on the west.
The excessive ratio of branches to trunks has created a serious capacity problem in the central tunnel, leading to plans to build a second tunnel parallel to the existing one. This project has been delayed for over ten years, with mounting construction costs, but is finally planned to begin construction in 2 days, with expected completion date 2026. At more than €500 million per underground kilometer, the second tunnel is the most expensive rail project built outside the Anglosphere; were costs lower, it would have been built already.
The Tokyo rail network is highly branched, and many lines reverse-branch using the subway. However, most core JR East lines have little branching. The three local lines (Yamanote, Chuo-Sobu, Keihin-Tohoku) don’t branch at all. Of the rapid lines, Chuo has two branches, and Tokaido and Yokosuka don’t branch. Moreover, the Chuo branch point, Tachikawa, is 37 km from Tokyo.
The northern and eastern lines branch more, but the effective branch-to-trunk ratio is reduced via reverse-branching. To the east, the Sobu Line has 5 branches, but they only split at Chiba, 39 km east of Tokyo. The Keiyo Line has 3 branches: the Musashino outer ring, and two eastern branches that also host some Sobu Line trains. The services to the north running through to Tokaido via the Tokyo-Ueno Line have 3 branches – the Utsunomiya, Takasaki, and Joban Lines – but some trains terminate at Ueno because there’s no room on the Tokyo-Ueno trunk for them. The services using the Yamanote Freight Line (Saikyo and Shonan-Shinjuku) have 2 southern branches (Yokosuka and Tokaido) and 3 northern ones (Utsunomiya, Takasaki, and a third Saikyo-only branch).
Conversely, all of these lines mix local and express trains on two tracks, with timed overtakes, except for the three non-branching local lines. The upper limit, beyond which JR East only runs local trains, appears to be 19 or 20 trains per hour, and near this limit local trains are consistently delayed 4 minutes at a time for overtakes.
Implications for Through-Running: Boston
In Boston, there are 7 or 8 useful southern branches: Worcester, Providence, Stoughton, Fairmount, the three Old Colony Lines, and Franklin if it’s separate from Fairmount. The Stoughton Line is planned to be extended to New Bedford and Fall River, making 8 or 9 branches, but the intercity character of the extension and the low commute volumes make it possible to treat this as one branch for scheduling purposes. To the north, there are 5 branches today (Fitchburg, Lowell, Haverhill, Newburyport, Rockport), but there are 2 decent candidates for service restoration (Peabody and Woburn).
The North-South Rail Link proposal has four-tracks, so the effective branch-to-trunk ratio is 3.5. It is not hard to run service every 15 minutes peak and every 30 off-peak with this amount of branching, and there’s even room for additional short-turn service on urban lines like Fairmount or inner Worcester and Fitchburg. But this comes from the fact that ultimately, Boston regional rail modernization would create an RER C and not an RER A, using my typology as explained on City Metric and here.
There are several good corridors for an RER A-type service in Boston, but those have had subway extensions instead: the Red Line to Braintree, the Orange Line to Malden, and now the Green Line Extension to Tufts. The remaining corridors could live with double service on an RER C-type service, that is, service every 7.5 minutes at the peak and every 15 off-peak. For this reason, and only for this reason, as many as 4 branches per trunk are acceptable in Boston.
Implications for Through-Running: New York
Let us go back to the original purpose of this discussion: New York through-running crayon. I have previously criticized plans that use the name Crossrail because it sounds modern but only provide a Thameslink or RER C. Independently of other factors, the ReThinkNYC plan has the same issues. It attempts to craft a sleek, modern regional rail system exclusively out of the existing Penn Station access tunnels plus a future tunnel across the Hudson.
Where Boston has about 7 commuter rail branches on each side, New York has 9 on Long Island (10 counting the Central Branch), 6 in Metro-North territory east of the Hudson, and 9 in New Jersey (11 counting the Northern Branch and West Shore Railroad). Moreover, one branch, the Hudson Line, has a reverse branch; where the Keiyo/Sobu reverse-branching in Tokyo and the Grand Central/Penn Station Access reverse-branching on the New Haven Line offer an opportunity to provide more service to a highly-branched line, the Hudson Line is a single line without branches.
The upshot is that even a four-track trunk, like the one proposed by both the RPA’s Crossrail NY/NJ plan and ReThinkNYC, cannot possibly take over all commuter lines. The frequency on each branch would be laughable. This is especially bad on the LIRR, where the branch point is relatively early (at Jamaica). The schedule would be an awkward mix of trains bound for the through-running system, East Side Access, and perhaps Downtown Brooklyn, if the LIRR doesn’t go through with its plan to cut off the Atlantic Branch from through-service and send all LIRR trains to Midtown Manhattan. Schedules would be too dependent between trains to each destination, and reliability would be low. ReThinkNYC makes this problem even worse by trying to shoehorn all of Metro-North, even the Harlem and Hudson Lines, into the same system, with short tunneled connections to the Northeast Corridor.
On the New Jersey side, the situation is easier. This is because two of the key branch points – Rahway and Summit – are pretty far out, respectively 33 and 37 km from Penn Station. The population density on branches farther out is lower, which means a train every 20 or 30 minutes off-peak is not the end of the world.
The big problem is the attempt to link the Erie lines into the same system. This makes too many branches, not to mention that the Secaucus loop between the Erie lines and the Northeast Corridor is circuitous. The original impetus behind my crayon connecting the South Side LIRR at Flatbush with the Erie lines via Lower Manhattan is that the Erie lines point naturally toward Lower Manhattan, and not toward Midtown. But this is also an attempt to keep the branch-to-trunk ratio reasonable.
The first time I drew New York regional rail crayon, I aimed at a coherent-looking system. The Hudson Line reverse-branched, and I was still thinking in terms of peak trains-per-hour count rather than in terms of a consistent frequency, but the inner lines looked like a coherent RER-style network. But the Hoboken-Flatbush tunnel still had 5 branches on the west, and the Morris and Essex-LIRR line, without a dedicated tunnel, had 4 to the east. My more recent crayon drops the West Shore Line, since it has the most freight traffic, leaving 4 branches, of which 1 (Bergen County) can easily be demoted to a shuttle off-peak, keeping base frequency on all branches acceptable without overserving the trunk; by my most recent crayon, there are still 4 branches, but there’s a note suggesting a way to cut this to 3 branches by building a new trunk. Moreover, several branches are reduced to shuttles (Oyster Bay, Waterbury) or circumferential tram-trains (West Hempstead) to avoid overloading the trunks. There’s a method behind the madness: in normal circumstances, there should not be more than 3 branches per double-track trunk.
I am not demanding that the RPA or ReThinkNYC put forth maps with multiple new trunk lines. The current political discussion is about Gateway, which is just 1 trunk line; it’s possible to also include what I call line 3 (i.e. the Empire Connection), which just requires a short realignment of an access track to Penn Station, but the lines to Lower Manhattan still look fanciful. New York has high construction costs, and the main purpose of my maps is to show what is possible at normal construction costs. But it would be useful for the studios to understand issues of frequency, reliability, and network coherence. This means no Secaucus loop, no attempt to build one trunk line covering all or almost all commuter lines, and not too many branches per trunk.
New York is an enormous city. It has 14 subway trunk lines, and many are full all day and overcrowded at rush hour. That, alone, suggests it should have multiple commuter rail trunk lines supplementing the subway at longer-range scale. It’s fine to build one trunk line at a time, as London is doing – these aren’t small projects, and there isn’t always the money for an entire network. But it’s important to resist the temptation to make the one line look more revolutionary than it is.
The simplest train schedules are when every train makes every stop. This means there are no required overtakes, and no need for elaborate track construction except for reasons of capacity. In nearly all cities in the world, double-track mainlines with flying junctions for branches are enough for regional rail. Schedule complexity comes from branching and short-turns, and from the decision which lines to join together, but it’s then possible to run independently-scheduled lines, in which delays don’t propagate. I have worked on a map as part of a proposal for Boston, and there, the only real difficulty is how to optimize turnaround times..
But then there’s New York. New York is big enough that some trunk lines have and need four tracks, introducing local and express patterns. It also has reverse-branching on some lines: the Hudson Line and New Haven Line can serve either Penn Station or Grand Central, and there are key urban stations on the connections from either station to either line. The presence of Jamaica Station makes it tempting to reverse-branch the LIRR. Everything together makes for a complex map. I talked in 2014 about a five- or six-line system, and even there, without the local/express artifacts, the map looks complicated. Key decisions turn out to depend on rolling stock, on scheduling, and on decisions made about intercity rail fares.
Here is what I drew last week. It’s a six-line map: lines 1 and 2 connect the Northeast Corridor on both sides plus logical branches and the Port Washington Branch of the LIRR, line 3 connects Hempstead with the Empire Corridor, line 4 connects the Harlem Line with the Staten Island Railway as a north-south trunk, line 5 connects the Erie Lines with the South Side LIRR lines, line 6 connects the Morris and Essex Lines with the LIRR Main Line.
As I indicated in the map’s text, there are extra possible lines, going up to 9; if I revised the map to include one line, call it line 7, I’d connect the Northern Branch and West Shore Railroad to a separate tunnel under 43rd Street, going east and taking over the LIRR portions of line 3; then the new line 3 would connect the Hudson Line with the Montauk Line (both Lower Montauk and the Babylon Branch) via an East River Tunnel extension. The other options are at this point too speculative even for me; I’m not even certain about line 6, let alone line 7, let alone anything else.
But the real difficulty isn’t how to add lines, if at all. It’s the reverse branch of lines 1 and 2. These two lines mostly go together in New Jersey and on the New Haven Line, but then take two different routes to Manhattan. The difficulty is how to assign local and express trains. The map has all line 1 trains going local: New Brunswick-Port Washington, or Long Branch-Stamford. Line 2 trains are a mix of local and express. This is a difficult decision, and I don’t know that this is the right choice. Several different scheduling constraints exist:
- Intercity trains should use line 1 and not line 2. This is for two reasons: the curve radius between Penn Station and Grand Central might be too tight for Shinkansen trains; and the Metro-North trunk north of Grand Central has no room for extra tracks, so that the speed difference between intercity and regional trains (e.g. no stop at Harlem-125th) would limit capacity. For the same reason, line 1 only has a peak of 6 trains per hour on the Northeast Corridor east of where the Port Washington Branch splits.
- Since not many regional trains can go between New Rochelle and Penn Station on the Northeast Corridor, they should provide local service – express service should all go via Grand Central.
- There are long segments with only four tracks, requiring track sharing between intercity trains and express regional trains. These occur between New Rochelle and Rye, and between the end of six-tracking in Rahway and New Brunswick. See details and a sample schedule without new Hudson tunnels here. This encourages breaking service so that in the Manhattan core, it’s the local trains that share tunnel tracks with intercity trains, while express trains, which share tracks farther out, are less constrained.
- Express trains on the New Jersey side should stay express on the New Haven Line, to provide fast service on some plausible station pairs like Newark-Stamford or New Rochelle-New Brunswick. Flipping local and express service through Manhattan means through-riders would have to transfer at Secaucus (which is plausible) or Penn Station (which is a bad idea no matter how the station is configured).
- There should be infill stops in Hudson County: at Bergenline Avenue for bus connections and the high local population density, and just outside the portal, at the intersection with the Northern Branch. These stops should be on line 2 (where they can be built new) and not line 1 (where the tunnels would need to be retrofitted), and trains cannot skip them, so the line that gets these stops should run locals.
It is not possible to satisfy all constraints simultaneously. Constraint 5 means that in New Jersey, line 2 should be local and line 1 should be express. Constraint 4 means the same should be true on the Metro-North side. But then constraints 2 and 3 encourage making line 1 local, especially on the Metro-North side. Something has to give.
On the map, the compromise is that there’s an infill stop at Bergenline but not at the intersection with the Northern Branch (which further encourages detaching the Northern Branch from line 5 and making it part of a Midtown-serving line 7). So the line 2 express trains are one stop slower than the line 1 locals between Newark and New York, which is not a huge problem.
The scheduling is still a problem, The four-track segment through Elizabeth between the six-track segments around Newark Airport and in Linden and Rahway has to be widened to six tracks; the four-track segment between the split with the North Jersey Coast Line and Jersey Avenue can mix three speed classes, with some express trains sharing tracks with intercity trains and others with local trains, but it’s not easy. At least on the Connecticut side, any high-speed rail service requires so many bypasses along I-95 that those bypasses can be used for overtakes.
At this point, it stops being purely about regional rail scheduling. The question of intercity rail fares becomes relevant: can people take intercity trains within the metro area with no or limited surcharge over regional trains? If so, then constraint 4 is no longer relevant: nobody would take regional trains on any segment served by intercity trains. In turn, there would be demand for local intercity trains, stopping not just at New Haven, New York, Newark, and Philadelphia, but also at Stamford, New Rochelle, perhaps Metropark (on new express platforms), and Trenton. In that case, the simplest solution is to flip lines 1 and 2 in New Jersey: line 1 gets the express trains to Trenton and the trains going all the way to Bay Head, line 2 gets the locals to Jersey Avenue, the Raritan Valley Line trains, and the Long Branch short-turns.
This, in turn, depends on rolling stock. Non-tilting high-speed trains could easily permit passengers with unreserved seats to pay commuter rail fare. On tilting trains, this is dicier. In Germany, tilting trains with unreserved tickets (ICE-T) have a computer constantly checking whether the train is light enough to be allowed to tilt, and if it is too heavy, it shuts down the tilt mechanism. This should not be acceptable for the Northeast Corridor. This might not be necessary for tilting Shinkansen (which are so light to begin with this isn’t a problem, and they do sell unreserved tickets in Japan), but it’s necessary for Pendolinos and for the Avelias that Amtrak just ordered. Selling reserved tickets at commuter rail fares is another option, but it might not be plausible given peak demand into New York.
The point of this exercise is that the best transit planning requires integrating all aspects: rolling stock, timetable, infrastructure, and even pricing. Questions like “can intercity trains charge people commuter rail fares for unreserved tickets?” affect express regional service, which in turn affects which branch connects to which trunk line.
Ultimately, this is the reason I draw expansive maps like this one. Piecemeal planning, line by line, leads to kludges, which are rarely optimized for interconnected service. New York is full of examples of poor planning coming from disintegrated planning, especially on Long Island. I contend that the fact that, for all of the Gateway project’s scope creep and cost escalations, there’s no proposed stop at Bergenline Avenue, is a prime example of this planning by kludge. To build the optimal line 2, the region really needs to know where lines 3-6 should go, and right now, there’s simply none of this long-term planning.
At the beginning of the month, I published a piece in Voice of San Diego calling for medium-speed rail investment in the Los Angeles-San Diego corridor, centering electrification. This was discussed in a 500-comment thread on California HSR Blog, in which area rail activist Paul Dyson ripped into my plan, arguing (among other things) that electrification is costlier and less useful than I think. Instead of reopening the debate on that particular corridor, I want to discuss a more general set of guidelines to when rail lines should be electrified.
I haven’t said so in these exact words, but I think North American rail authorities and activists underrate electrification. As a result, I find myself persistently prescribing electrification and defending it when it’s already on the table, even as I attack other rail investments as wasteful. On social media and in blog comments I find myself having to constantly explain to people that no, a $20 billion New York regional rail plan should not use dual-mode locomotives but rather spend $250 million on New Jersey-side electrification.
A year and a half ago I wrote about why small, dense countries should fully electrify. The reasons laid out in that post are included in the guidelines below, but there are some additional circumstances justifying electrification.
Narrow stop spacing
Each train has a stop penalty – a total amount of time it loses to making each stop. The penalty is based on dwell time, line speed, and train acceleration and braking performance. If the line speed is 130 km/h, then the penalty excluding dwell time is about 35 seconds for a FLIRT and 80 seconds for a diesel GTW. This 45-second difference per stop is the same if there is a stop every 3 km or if there is a stop every 50 km.
Stop spacing is narrower on commuter lines than on intercity lines, so electrification usually starts from commuter rail. The first mainline electrification in the world was in Paris on the commuter lines serving Gare d’Orsay; subsequently the commuter lines in Paris, London, Tokyo, Berlin, New York, Philadelphia, and other major cities were wired. In many of these cases, commuter rail was electrified decades before intercity mainlines: for example, Japan started electrifying Tokyo’s innermost commuter lines in the 1900s and completed them in the 1920s and early 30s, but took until 1956 to electrify the first intercity line, the Tokaido Line.
However, in some dense regions, even the intercity lines have many stops. Cities in Israel, Belgium, the Netherlands, and Switzerland are just not very far apart, which blurs the distinction between regional and intercity lines somewhat. Switzerland is all-electrified, and my post from 2015 argued that the first three should be, too. In the US, there are specific regions where continuous sprawl has led to the same blurring: the Northeast Corridor, Southern California, Central and South Florida, New England. All are characterized by high population density. New England has closely spaced cities, whereas the LA-San Diego corridor and corridors within Florida have so much sprawl that there have to be several stations per metro area to collect people, reducing stop spacing.
Frequent sharp curves between long straight segments
Electric multiple units (EMUs) can make use of their high acceleration not at stations, but also at slow restrictions due to curves. They are also capable of higher cant deficiency than top-heavy diesel locomotives, since they have low center of gravity, but the difference for non-tilting trains is not so big. A uniformly curvy line does not offer EMUs much advantage, since all trains are slow – if anything, the lower the top speed, the less relevant acceleration is.
The big opportunity to accelerate is then when a mostly straight line is punctured by short, sharp curves. Slowing briefly from 130 km/h to 70 km/h and then speeding back up costs a FLIRT on the order of 15 seconds. A diesel train, whether powered by a locomotive or by diesel multiple units (DMUs), can’t hope to have the required power-to-weight ratio for such performance.
EMUs’ better acceleration profile makes them better-suited for climbing hills and mountains. Modern EMUs, especially low- and medium-speed ones optimized for high acceleration, can effortlessly climb 4% grades, at which point DMUs strain and diesel locomotives require helper engines. When the terrain is so mountainous that tunnels are unavoidable, electric trains do not require ventilation in their tunnels. As a result, some long rail tunnels were electrified from the start. The combination of uphill climbs and tunnels is literally toxic with diesels.
Cheap, clean electricity
Electrification has lower operating costs and lower greenhouse gas emissions in areas where the electricity is powered by cheap hydro or geothermal power than in areas where it is powered by fossil fuels. Switzerland became the only country with 100% rail electrification because it had extensive hydro power in the middle of the 20th century and was worried about relying on coal shipments from Nazi Germany during the war.
This is especially useful in far northern countries, like Sweden and Canada, which have low population density and little evaporation, leading to extensive hydro potential per capita. Despite its low density, Sweden has electrified about two thirds of its rail network. In the US, this is the most relevant to the Pacific Northwest.
But in the future, the falling cost of solar power means that clean electricity is becoming more affordable, fast. This favors electrification in more places, starting from sunny regions like most of the US.
Small installed diesel base
A rich or middle-income country building railroads for the first time, or expanding a small system, needs to build new yards, train maintenance crews, and procure spare parts. It should consider electrifying from the start in order to leapfrog diesel technology, in the same manner many developing countries today leapfrog obsolete technologies like landline phones. In contrast, a larger installed base means electrification has to clear a higher bar to be successful, which is why Japan, France, and other major core networks do not fully electrify.
The US situation is dicey in that it does have a lot of diesel equipment. However, this equipment is substandard: reliability is low, with mean distance between failures (MDBF) of about 45,000 km on the LIRR compared with 680,000 on new EMUs (source, pp. 30-31); the trains are very heavy, due to past FRA regulations; and the equipment is almost universally diesel locomotives rather than DMUs, which makes the acceleration problem even worse than it is for GTWs. Total acceleration and deceleration penalty on American diesel locomotives is not 80 seconds but 2-2.5 minutes.
Because North America underrates electrification, some people who self-identify as forward-thinking propose DMUs. Those require new maintenance regimes and facilities, creating an entire installed base from scratch instead of moving forward to EMUs.
Globally, the installed diesel base for high-performance lines is vanishingly small. The technology exists to run diesel trains at more than 200 km/h, but it’s limited in scope and the market for it is thin.
Through-service to electric lines
Whenever a diesel line is planned to run through to an electric line, it should be a prime candidate for electrification. Dual-mode locomotives exist, but are heavy and expensive; dual-mode multiple units are lighter, but are still boutique products.
This is especially true for the two biggest investments a network can make in passenger rail: RER tunnels, and HSR. RER tunnels involve expensive urban tunneling. When a kilometer of urban subway costs $250 million and a kilometer of catenary costs $2 million, the economics of the latter become stronger. Not to mention that RERs are typically short-hop commuter rail, with frequent stops even on the branches. HSR is a different beast, since it’s intercity, but the equipment is entirely electric. Running through to a diesel branch means towing the train behind a diesel locomotive, which means the expensive HSR traction equipment is idle for long periods of time while towed; this is at best an interim solution while the connecting legacy line is wired, as in the line to Sables d’Olonne.
Nearly complete electrification
Areas where the rail network is almost completely electrified benefit from finishing the job, even if individually the diesel lines are marginal candidates for electrification. This is because in such areas, there is a very large installed electric base, and a smaller diesel base. In small countries the remaining diesel base is small, and there are efficiencies to be had from getting rid of it entirely. This is why the Netherlands and Belgium should finish electrification, and so should Denmark and Israel, which are electrifying their main lines.
This is somewhat less applicable to larger countries, such as Sweden, Poland, and especially Japan. However, India is aggressively electrifying its rail network and planning even more. Note that since networks electrify their highest-trafficked lines first, the traffic can be almost completely electrified even if the trackage is not. For example, Russia is about 50% electrified, but 86% of freight tonnage is carried on electric trains, and the share of ton-km is likely higher since the Trans-Siberian Railway is electrified.
This also applies to networks smaller than an entire country. Commuter rail systems that are mostly electrified, such as the LIRR, should complete electrification for the same reason that mostly electrified countries should. In New England and Southern California, regional rail electrification is desirable purely because of the acceleration potential, and this also makes full electrification desirable, on the principle that a large majority of those two regions’ networks have enough potential traffic to justifying being wired without considering network effects.
Every place – a country, an isolated state or province, a commuter rail system – that is at least 50-60% electrified should consider fully electrifying. The majority of the world that is below that threshold should still wire the most important lines, especially regional lines. Capital-centric countries like Britain and France often get this wrong and focus on the intercity lines serving the capital, but there are low-hanging fruit in the provincial cities. For example, the commuter rail networks in Marseille, Lyon, and Bordeaux are almost entirely electrified, but have a few diesel lines; those should be wired.
In North America, electrification is especially underrated. Entire commuter rail networks – the MBTA, Metra, Metrolink, MARC/VRE, GO Transit, AMT, tails on the New York systems – need to be wired. This is also true of short-range intercity lines, including LA-San Diego, Chicago-Milwaukee, Boston-Portland, Toronto-Niagara Falls, and future New York-Scranton. It is important that good transit activists in those regions push back and support rail electrification, explaining its extensive benefits in terms of reliability and performance and its low installation cost.
A few weeks ago, I published a piece in City Metric contrasting two ways of through-running regional rail, which I identify with the RER A and C in Paris. The RER C (or Thameslink) way is to minimally connect two stub-end terminals pointing in opposite directions. The RER A (or Crossrail) way is to build long city-center tunnels based on urban service demand but then connect to legacy commuter lines to go into the suburbs. Crossrail and the RER A are the two most expensive rail tunnels ever built outside New York, but the result is coherent east-west regional lines, whereas the RER C is considerably more awkward. In this post I’d like to explain what this means for New York.
As I said in the City Metric piece, the current plans for through-running in New York are strictly RER C-style. There’s an RPA project called Crossrail New York-New Jersey, but the only thing it shared with Crossrail is the name. The plan involves new Hudson tunnels, but service would still use the Northeast Corridor and LIRR as they are (with an obligatory JFK connection to get the politicians interested). I alluded in the piece to RER A-like improvements that can be done in New York, but here I want to go into more detail into what the region should do.
Regional rail to Lower Manhattan
Regional rail in New York should serve not just Midtown but also Lower Manhattan. Owing to Lower Manhattan’s intense development in the early 20th century already, no full-size train stations were built there in the era of great urban stations. It got ample subway infrastructure, including by the Hudson Tubes (now PATH), but nothing that could be turned into regional rail. Therefore, regional rail plans today, which try to avoid tunneling, ignore Lower Manhattan entirely.
The Institute for Rational Urban Mobility, longtime opponent of the original ARC project and supporter of through-running, even calls for new tunnels between Hoboken and Midtown, and not between Hoboken and Lower Manhattan. I went to an IRUM meeting in 2009 or 2010, when Chris Christie had just gotten elected and it was not clear what he’d do about ARC, and when people pitched the idea, I asked why not go Hoboken-Lower Manhattan. The reply was that it was beyond the scope of “must connect to Penn Station” and at any rate Lower Manhattan wasn’t important.
In reality, while Midtown is indeed a bigger business district than Lower Manhattan, the job density in Lower Manhattan is still very high: 320,000 people working south of Worth Street in 1.9 km^2, compared with 800,000 in 4 km^2 in Midtown. Nothing in Ile-de-France is this dense – La Defense has 180,000 jobs and is said to have “over 800 jobs/ha” (link, PDF-p. 20), and it’s important enough that the RER A was built specifically to serve it and SNCF is planning a TGV station there.
Regional trains to Lower Manhattan are compelled to be more RER A-style. More tunnels are needed than at Penn Station, and the most logical lines to connect create long urban trunks. In a post from two years ago, I consistently numbered the regional lines in New York 1-5 with a non-through-running line 6:
- The legacy Northeast Corridor plus the Port Washington Branch, via the existing Hudson tunnels.
- More lines in New Jersey (some Northeast Corridor, some Morris and Essex) going to the New Haven Line via new Hudson tunnels and Grand Central.
- Some North Side LIRR lines (presumably just Hempstead and the Central Branch) to the Hudson Line via Penn Station and the Empire Connection; some LIRR trains should terminate at Penn Station, since the Hudson Line can’t support as much traffic.
- The Harlem Line connecting to the Staten Island Railway via Lower Manhattan and a Staten Island-Manhattan tunnel, the most controversial piece of the plan judging by comments.
- The New Jersey lines inherited from the Erie Railroad (including the Northern Branch) to the South Side LIRR (to Far Rockaway, Long Beach, and Babylon) via Lower Manhattan.
- More North Side LIRR lines (probably the Ronkonkoma and Port Jefferson branches) to Grand Central via East Side Access.
The Lower Manhattan lines, numbered 4 and 5, have long trunks. Line 4 is a basic north-south regional line; it’s possible some trains should branch to the Hudson Line, but most would stay on the Harlem Line, and it’s equally possible that the Hudson Line trains to Grand Central should all use line 2. Either configuration creates very high all-day frequency between White Plains and St. George, and still high frequency to both Staten Island branches, with many intermediate stations, including urban stops. Line 5 goes northwest-southeast, and has to have, at a minimum, stops at Pavonia, Lower Manhattan, Downtown Brooklyn, and then all the LIRR Atlantic Branch stops to and beyond Jamaica.
More stops within new tunnels
Even new tunnels to Midtown can be built with the RER A concept in mind. This means more stations, for good connections to existing subway and bus lines. This is not superficially obvious from the maps of the RER A and C: if anything, the RER C has more closely-spaced stops within Paris proper, while the RER A happily expresses from La Defense to Etoile and beyond, and completely misses Metro 5 and 8. Crossrail similarly isn’t going to have a transfer to every Underground line – it’s going to miss the Victoria and Piccadilly lines, since connecting to them would have required it to make every Central line stop in the center of London, slowing it down too much.
However, the important feature of the RER A is the construction of new stations in the new tunnels – six of them, from La Defense to Nation. The RER C was built without any new stations, except (later) infill at Saint-Michel, for the transfer to the RER B. The RER C’s urban stations are all inherited legacy stations, even when underground (as some on the Petite Ceinture branch to Pontoise are), since the line was built relatively cheaply, without the RER A’s caverns. This is why in my City Metric piece, I refer to the RER B as a hybrid of the RER A and C approaches: it is a coherent north-south line, but every station except Saint-Michel is a legacy station (Chatelet-Les Halles is shared with the RER A, Gare du Nord is an existing station with new underground platforms).
With this in mind, there are several locations where new regional rail tunnels in New York could have new stations. I wrote two years ago about Bergenline Avenue, within the new Hudson tunnels. The avenue hosts very high bus and jitney frequency, and today Manhattan-bound commuters have to go through Port Authority, an obsolete structure with poor passenger experience.
Several more locations can be identified. Union Square for line 4 has been on the map since my first post on the subject. More stations on line 5 depend on the alignment; my assumption is that it should go via the approach tracks to the Erie’s Pavonia terminal, but if it goes via Hoboken then there should be a station in the Village close to West 4th Street, whereas if it goes via Exchange Place then there should be a station at Journal Square, which is PATH’s busiest New Jersey station.
On lines 4 and 5, there are a few additional locations where a station should be considered, but where there are strong arguments against, on the grounds of speed and construction cost: Brooklyn Heights, Chinatown (on line 5 via Erie, not 4), a second Lower Manhattan station on line 4 near South Ferry (especially if the main Lower Manhattan station is at City Hall rather than Fulton Street).
There are also good locations for more stations on the Metro-North Penn Station Access routes, both the New Haven Line (given to line 1) and the Hudson Line (given to line 3). Current plans for Penn Station Access for the New Haven Line have four stations in the Bronx, but no connection to Astoria, and a poor connection to the Bx12 buses on Fordham Road. A stop on Pelham Parkway would give a stronger connection to the Bx12 than the Coop City station, which the Bx12 reaches via a circuitous route passing through the 6 train’s northern terminus at Pelham Bay Parkway. Astoria has been studied and rejected on two grounds: one is construction difficulties, coming from the constrained location and the grade; the other is low projected ridership, since current plans involve premium fares, no fare integration with the subway and buses, and low off-peak frequency. The first problem may still be unsolvable, but the second problem is entirely the result of poor industry practices.
On the Empire Connection, there are plans for stops at West 62nd and West 125th Street. It is difficult to add more useful stations, since the line is buried under Riverside Park, far from Upper West Side and Washington Heights development. The 125th Street valley is one of few places where urban development reaches as far west as the Empire Connection. That said, Inwood is low-lying and it’s possible to add a station at Dyckman Street. In between, the only semi-plausible locations are 145th Street or 155th-158th (not both, they’re too close), and even those are marginal. All of these neighborhoods, from West Harlem north, have low incomes and long commutes, so if it’s possible to add stations, Metro-North should just do it, and of course make sure to have full fare integration with the subway and buses. The one extra complication is that there are intercity trains on this line and no room for four-tracking, which limits the number of infill stops that can support high frequency (at worst every 10 minutes).
Infill stops on existing lines
The existing regional lines in New York have very wide stop spacing within the city. It’s a general feature of North American commuter rail; I wrote about it 5 years ago in the context of Chicago, where Metra is even more focused on peak suburb-to-CBD commutes than the New York operators. In most North American cities I heartily endorse many infill stops on commuter rail. I have a fantasy map for Los Angeles in which the number of stops on inner commuter rail lines triples.
However, New York is more complicated, because of the express subway lines. In isolation, adding stops to the LIRR west of Jamaica and to Metro-North between Harlem and Grand Central would be a great idea. However, all three lines in question – Metro-North, the LIRR Main Line, and the Atlantic Branch – closely parallel subway lines with express tracks. It’s still possible to boost urban ridership by a little by having a commuter rail stop for each express subway stop, which would mean 86th and 59th Streets in Manhattan and Utica Avenue in Brooklyn, but the benefits are limited. For this reason, my proposed line 4 tunnel from Grand Central down to Lower Manhattan has never had intermediate stations beyond Union Square. For the same reason, while I still think the LIRR should build a Sunnyside Junction station, I do not endorse infill elsewhere on the Main Line.
That said, there are still some good candidates for infill. Between Broadway Junction and Jamaica, the LIRR parallels only a two-track subway line, the J/Z, which is slow, has poor connections to Midtown (it only goes into Lower Manhattan), and doesn’t directly connect Jamaica with Downtown Brooklyn. The strongest location for a stop is Woodhaven Boulevard, which has high bus ridership. Lefferts is also possible – it hosts the Q10 bus, one of the busiest in the borough and the single busiest in the MTA Bus system (most buses are in the New York City Transit bus division instead). It’s 4.7 km from Woodhaven to Broadway Junction, which makes a stop around Logan or Crescent feasible, but the J/Z is much closer to the LIRR west of Crescent Street than east of it, and the A/C are nearby as well.
Another LIRR line that’s not next to a four-track subway is the inner Port Washington Branch. There are no stops between the Mets and Woodside; there used to be several, but because the LIRR had high fares and low frequency, it could not compete once the subway opened, and those stations all closed. There already are plans to restore service to Elmhurst, the last of these stations to be closed, surviving until 1985. If fares and schedules are competitive, more stations are possible, at new rather than old locations: Queens Boulevard with a transfer to a Triboro RX passenger line, and two Corona stops, at Junction Boulevard and 108th Street. Since the Port Washington Branch is short, it’s fine to have more closely-spaced stops, since no outer suburbs would suffer from excessive commutes as a result.
Beyond Jamaica, it’s also possible to add LIRR stops to more neighborhoods. There, the goal is to reduce commute length, which requires both integrated fares (since Southeast Queens is lower middle-class) and more stops. However, the branches are long and the stop spacing is already not as wide as between Jamaica and Broadway Junction. The only really good infill location is Linden Boulevard on the Atlantic Branch; currently there’s only a stop on the Montauk Line, farther east.
In New Jersey, the situation is different. While the stop spacing east of Newark is absurdly long, this is an artifact of development patterns. The only location that doesn’t have a New Jersey Transit commuter rail stop that could even support one is Harrison, which has a PATH station. Additional stations are out of the question without plans for intense transit-oriented development replacing the warehouses that flank the line. A junction between the Northern Branch and line 2, called Tonnelle in my post on The Transport Politic from 2009, is still feasible; another stop, near the HBLR Tonnelle Avenue station, is feasible on the same grounds. But the entire inner Northern Branch passes through hostile land use, so non-junction stations are unlikely to get much ridership without TOD.
West or south of Newark, the land use improves, but the stop spacing is already quite close. Only two additional locations would work, one on the Northeast Corridor near South Street, and one on the Morris and Essex Lines at the Orange Street stop on the Newark Subway. South Newark is dense and used to have a train station, and some area activists have hoped that plans to extend PATH to the airport would come with a South Street stop for additional urban service. At Orange Street the land use isn’t great, since a highway passes directly overhead, but the Newark Subway connection makes a station useful.
Finally, in Manhattan, the East River Tunnels have four tracks, of which Amtrak only needs two. This suggests an infill East Side station for the LIRR. There are strong arguments against this – namely, cost, disruption to existing service, and the fact that East 33rd Street is not really a prime location (the only subway connection there is the 6). On the other hand, it is still far denser than anywhere in Brooklyn and Queens where infill stations are desirable, and the 6’s ridership at 33rd Street is higher than that of the entire Q10 or Bx12.
The RER A and Crossrail are not minimal tunnels connecting two rail terminals. They are true regional subways, and cost accordingly. Extracting maximum ridership from mainline rail in New York requires building more than just short connections like new Hudson tunnels or even a Penn Station-Grand Central connection.
While some cities are blessed with commuter rail infrastructure that allows for coherent through-service with little tunneling (like Boston) or no tunneling at all (like Toronto), New York has its work cut out for it if it wants to serve more of the city than just Jamaica and the eastern Bronx. The good news is that unlike Paris and London, it’s possible to use the existing approaches in Brooklyn and New Jersey. The bad news is that this still involves a total of 30 km of new tunnel, of which only about 7 are at Penn Station. Most of these new tunnels are in difficult locations – underwater, or under the Manhattan CBD – where even a city with reasonable construction costs like Paris could not build for $250 million per km. The RER A’s central segment, from Nation to Auber, was about $750 million/km, adjusted for inflation.
That said, the potential benefits are commensurate with the high expected costs. Entire swaths of the city that today have some of the longest commutes in the United States, such as Staten Island and Eastern Queens, would be put within a reasonable distance of Midtown. St. George would be 6 minutes from Lower Manhattan and perhaps 14 from Grand Central. Siting infill stations to intersect key bus routes like Bergenline, Woodhaven, and Fordham, and making sure fares were integrated, would offer relatively fast connections even in areas far from the rail lines.
The full potential of this system depends on how much TOD is forthcoming. Certainly it is easier to extract high ridership from rapid transit stations that look like Metrotown than from ones that look like typical suburban American commuter rail stops. Unfortunately, New York is one of the most NIMBY major cities in the first world, with low housing growth, and little interest in suburban TOD. Still, at some locations, far from existing residential development, TOD is quite likely. Within the city, there are new plans for TOD at Sunnyside Yards, just not for a train station there.
The biggest potential in the suburbs is at White Plains. Lying near the northern terminus for most line 4 trains, it would have very good transit access to the city and many rich suburbs in between. It’s too far away from Manhattan to be like La Defense (it’s 35 km from Grand Central, La Defense is 9 km from Chatelet-Les Halles), but it could be like Marne-la-Vallee, built in conjunction with the RER A.
Right now, the busiest commuter lines in New York – both halves of the Northeast Corridor and the LIRR Main Line – are practically intercity, with most ridership coming from far out. However, it’s the inner suburbs that have the most potential for additional ridership, and middle suburbs like White Plains, which is at such distance that it’s not really accurate to call it either inner or outer. The upper limit for a two-track linear route with long trains, high demand even in the off-peak hours, and high ridership out of both ends, is around a million riders per weekday; higher ridership than that is possible, but only at the levels of overcrowding typical of Tokyo or Shanghai. Such a figure is not out of the question for New York, where multiple subway lines are at capacity, especially for the more urban lines 4 and 5. Even with this more limited amount of development, very high ridership is quite likely if New York does commuter rail right.
In 2009, studies began for a replacement of the Baltimore and Potomac (B&P) Tunnel. This tunnel, located immediately west of Baltimore Penn Station, has sharp curves, limiting passenger trains to about 50 km/h today. The plan was a two-track passenger rail tunnel, called the Great Circle Tunnel since it would sweep a wide circular arc; see yellow line here. It would be about 3 kilometers and cost $750 million, on the high side for a tunnel with no stations, but nothing to get too outraged about. Since then, costs have mounted. In 2014, the plan, still for two tracks, was up to $1 billion to $1.5 billion. Since then, costs have exploded, and the new Final Environmental Impact Statement puts the project at $4 billion. This is worth getting outraged about; at this cost, even at half this cost, the tunnel should not be built. However, unlike in some other cases of high construction costs that I have criticized, here the problem is not high unit costs, but pure scope creep. The new scope should be deleted in order to reduce costs; as I will explain, the required capacity is well within the capability of two tracks.
First, some background, summarized from the original report from 2009, which I can no longer find: Baltimore was a bottleneck of US rail transportation in the mid-19th century. In the Civil War, there was no route through the city; Union troops had to lug supplies across the city, fighting off mobs of Confederate sympathizers. This in turn is because Baltimore’s terrain is quite hilly, with no coastal plain to speak of: the only flat land on which a railroad could be easily built was already developed and urbanized by the time the railroad was invented. It took until the 1870s to build routes across the city, by which time the US already had a transcontinental railroad. Moreover, intense competition between the Pennsylvania Railroad (PRR) and the Baltimore and Ohio (B&O) ensured that each company would built its own tunnel. The two-track B&P is the PRR tunnel; there’s also a single-track freight tunnel, originally built by the B&O, now owned by CSX, into which the B&O later merged.
Because of the duplication of routes and the difficult geography, the tunnels were not built to high standards. The ruling grade on the B&P is higher than freight railroads would like, 1.34% uphill departing the station, the steepest on the Northeast Corridor (NEC) south of Philadelphia. This grade also reduces initial acceleration for passenger trains. The tunnel also has multiple sharp curves, with the curve at the western portal limiting trains today to 30 mph (about 50 km/h). The CSX tunnel, called Howard Street Tunnel, has a grade as well. The B&P maintenance costs are high due to poor construction, but a shutdown for repairs is not possible as it is a key NEC link with no possible reroute.
In 2009, the FRA’s plan was to bypass the B&P Tunnel with a two-track passenger rail tunnel, the Great Circle Tunnel. The tunnel would be a little longer than the B&P, but permit much higher speeds, around 160 km/h, saving Acela trains around 1.5 minutes. Actually the impact would be even higher, since near-terminal speed limits are a worse constraint for trains with higher initial acceleration; for high-performance trains, the saving is about 2-2.5 minutes. No accommodation was made for freight in the original plan: CSX indicated lack of interest in a joint passenger and freight rail tunnel. Besides, the NEC’s loading gauge is incompatible with double-stacked freight; accommodating such trains would require many small infrastructure upgrades, raising bridges, in addition to building a new tunnel.
In contrast, the new plan accommodates freight. Thus, the plan is for four tracks, all built to support double-stacked freight. This is despite the fact that there is no service plan that requires such capacity. Nor can the rest of the NEC support double-stacked freight easily. Of note, Amtrak only plans on using this tunnel under scenarios of what it considers low or intermediate investment into high-speed rail. Under the high-investment scenario, the so-called Alternative 3 of NEC Future, the plan is to build a two-track tunnel under Downtown Baltimore, dedicated to high-speed trains. Thus, the ultimate plan is really for six tracks.
Moreover, as pointed out by Elizabeth Alexis of CARRD, a Californian advocacy group that has criticized California’s own high-speed rail cost overruns, the new tunnel is planned to accommodate diesel trains. This is because since 2009, the commuter rail line connecting Baltimore and Washington on the NEC, called the MARC Penn Line, has deelectrified. The route is entirely electrified, and MARC used to run electric trains on it. However, in the last few years MARC deelectrified. There are conflicting rumors as to why: MARC used the pool of Amtrak electric locomotives, and Amtrak is stopping maintaining them as it is getting new locomotives; Amtrak is overcharging MARC on electricity; MARC wants fleet compatibility with its two other lines, which are unelectrified (although the Penn Line has more ridership than both other lines combined). No matter what, MARC should immediately reverse course and buy new electric trains to use on the Penn Line.
Freight trains are more complicated – all US freight trains are dieselized, even under catenary, because of a combination of unelectrified yards and Amtrak’s overcharging on electric rates. However, if freight through the Great Circle Tunnel is desired, Amtrak should work with Norfolk Southern on setting up an electric district, or else Norfolk Southern should negotiate trackage rights on CSX’s existing tunnel. If more freight capacity is desired, private companies NS and CSX can spend their own money on freight tunnels.
In contrast, a realistic scenario would ignore freight entirely, and put intercity and regional trains in the same two-track tunnel. The maximum capacity of a two-track high-speed rail line is 12 trains per hour. Near Baltimore Penn the line would not be high-speed, so capacity is defined by the limit of a normal line, which is about 24 tph. If there is a service plan under which the MARC Penn Line could get more than 12 tph at the peak, I have not seen it. The plans I have seen call for 4 peak tph and 2 off-peak tph. There is a throwaway line about “transit-like” service on page 17, but it’s not clear what is meant in terms of frequency.
Regardless of what the state of Maryland thinks MARC could support, 12 peak regional tph through Baltimore is not a reasonable assumption in any scenario in which cars remain legal. The tunnels are not planned to have any stations, so the only city station west of Baltimore Penn is West Baltimore. Baltimore is not a very dense city, nor is West Baltimore, most famous for being the location of The Wire, a hot location for transit-oriented development. Most of Baltimore’s suburbs on the Penn Line are very low-density. In any scenario in which high-speed rail actually fills 12 tph, many would be long-range commuters, which means people who live in Baltimore and work in Washington would be commuting on high-speed trains and not on regional trains. About the upper limit of what I can see for the Penn Line in a realistic scenario is 6 tph peak, 3-4 tph off-peak.
Moreover, there is no real need to separate high-speed and regional trains for reasons of speed. High-speed trains take time to accelerate from a stop at Baltimore: by the portal, even high-acceleration sets could not go much faster than 200 km/h. An in-tunnel speed limit in the 160-180 km/h area only slows down high-speed trains by a few seconds. Nor does it lead to any noticeable speed difference with electrified regional trains, which would reduce capacity: modern regional trains like the FLIRT accelerate to 160 km/h as fast as the fastest-accelerating high-speed train, the N700-I, both having an acceleration penalty of about 25 seconds.
The upshot is that there is no need for any of the new scope added since 2009. There is no need for four tracks; two will suffice. There is no need to design for double-stacked freight; the rest of the line only accommodates single-stacked freight, and the NEC has little freight traffic anyway. Under no circumstances should diesel passenger trains be allowed under the catenary, not when the Penn Line is entirely electrified.
The new tunnel has no reason to cost $4 billion. Slashing the number of tunnels from four to two should halve the cost, and reducing the tunnels’ size and ventilation needs should substantially reduce cost as well. With the potential time gained by intercity and regional trains and the reduced maintenance cost, the original budget of $750 million is acceptable, and even slightly higher costs can be justified. However, again because the existing two-track capacity can accommodate any passenger rail volume that can be reasonably expected, the new tunnel is not a must-have. $4 billion is too high a cost, and good transit activists should reject the current plan.
As I mentioned in yesterday’s post, negotiations in New Jersey between Governor Chris Christie and the state legislature have resulted in a significant increase in the state fuel tax. The money will raise $16 billion for funding the eight-year Transportation Trust Fund plan, and be matched with federal funds to bring the amount up to $32 billion. Unfortunately, the money is being wasted. Details of most of the plan remain vague, but it appears most of the money will go to road repair; for all I know, $4 billion a year is a reasonable amount for this. But one component of the plan is extension of the Hudson-Bergen Light Rail system north into Bergen County, along the Northern Branch. This is at best a marginal project, and in the long run would make regional rail modernization in Northern New Jersey more difficult.
Despite its name, the HBLR only operates in Hudson County. Plans for extension into Bergen County along the Northern Branch still play an outsized political role due to the name of the line, but have not been realized yet. Right now, the line is partly the light rail system of Jersey City, and partly a circumferential line linking dense areas west of the Hudson, as somewhat of a circumferential. As such, it is a combination of a radial and circumferential. The Northern Branch would send it 13 km farther north into suburbia, terminating in Englewood, a town center with a fraction of the job density of the Jersey City CBD. Projected weekday ridership is 21,000, a little more than 1,500 per km, weak for an urban light rail line. (The HBLR’s existing ridership is 54,000 per weekday on 55 km of route.)
The original cost estimate of the Northern Branch extension was $150 million, low for the length of the line. While reactivating a closed commuter rail like the Northern Branch should be cheaper, the line is single-track still hosts some freight service, so light rail would have to build new tracks in the same right-of-way, raising the cost range to that of urban light rail. Unfortunately, the cost rapidly escalated: by 2009 it was up to $800-900 million, and in 2015, after the proposal was shortened to its current length from an 18 km proposal going deeper into the Bergen County suburbs, the cost was up to $1 billion. The cost per rider is still much better than that of the Gateway Tunnel, but it makes the project marginal at best.
While the high cost may be surprising, at least to the reader who is unused to the expense of building in or near New York, the limited ridership is not. The original plan, going beyond Englewood, would have terminated the line in Tenafly, a wealthy suburb where my advisor at Columbia used to live. Many people in Tenafly objected to that plan, not so much on the usual NIMBY grounds of traffic and noise as on the grounds that the line would not be of much use to them. They were interested in taking public transit to go to Manhattan, and the HBLR system would not be of any use. Of course, Columbia professors would not be using a rail network that went directly to Midtown or Lower Manhattan, but most of the suburb’s Manhattan-bound residents work in the CBD and not at Columbia.
I would probably not be this adamantly against the Northern Branch project if it were just one more over-budget light rail line at $45,000 per projected rider. The US has no shortage of these. Rather, it’s the long-term effect on regional rail.
The Northern Branch would make a good commuter rail line, going from Pavonia (or possibly Hoboken) north to Nyack, connecting to the HBLR at its present-day northern terminus, with about the same stop spacing as the proposed HBLR extension. Potentially it could even get a loop similar to the proposed Secaucus loop of the Gateway project allowing it to enter Penn Station directly. An even better connection would involve a second tunnel between Pavonia, Lower Manhattan, and Atlantic Terminal on the LIRR, with a new transfer station at the junction of the Northern Branch and the Northeast Corridor. Consult this map, depicting the inner segments of various potential commuter lines: the Northern Branch is the easternmost yellow line, the Northeast Corridor is in red and green.
The importance of the Northern Branch for regional rail is threefold. First, the easternmost line in North Jersey today, the Pascack Valley Line, misses a large swath of territory farther east, which is covered by the Northern Branch and by the West Shore Line. The West Shore Line actually passes through somewhat denser suburbs, with more Manhattan-bound commuters, but is a major freight route, whereas the Northern Branch has little freight traffic, which can be scheduled around passenger trains or even kicked out. Second, again shared with the West Shore Line, the Northern Branch provides a north-south line in Hudson County west of Bergen Hill, where there is suitable land for transit-oriented development. And third, the terminus, Nyack, is a town center with a walkable core.
I wouldn’t really object to making the Northern Branch light rail if it were cheap. At the original cost estimate of $150 million, I would be mildly annoyed by the lack of long-term thinking, but I’d also recognize that the cost per rider was low, and at worst the state would have to redo a $150 million project. At $1 billion, the calculus changes considerably; it’s a significant fraction of what a tunnel under the Hudson should cost (though not what it does cost given the extreme amount of scope creep).
High costs, as I said in 2011, should not be an excuse to downgrade transit projects to a cheaper, less useful category (such as from a subway to light rail). In this case we see the opposite happen: high costs are a reason to reject a downgraded project, since the cost per rider is no longer low enough to justify shrugging off the long-term effect on regional rail restoration.
I support through-running of regional trains: as far as possible, trains should not terminate in major city centers, but instead run through to urban neighborhoods and suburbs on the other side of the CBD. My first blog posts made this point about New York, and over the years I’ve written about this in the contexts of New York, Boston, Washington, Chicago, and Tel Aviv. However, in secondary cities, through-running is not always appropriate policy. If a city is near the edge and not at the center of its metro area, then quite often it’s preferable to run a separate service, which may overlap the primary city’s regional rail system. In some cases, through-running is actively harmful; unfortunately, this is currently done in San Jose and Providence.
Consider the following example city:
The metro area lies on an east-west rail line, and consists of a central city several suburbs; higher-density areas are denoted by darker shades, with the primary CBD in the darkest shade. The city proper also has five secondary CBDs, two of which are on the rail line. On the west, one suburb, really a secondary city, is larger than the rest, and has its own CBD, as job-dense as one of the primary city’s secondary CBDs. With rough symmetry of suburban demand west and east, there is no good reason why trains should not through the primary CBD, and good reasons why they should:
- People in the eastern suburbs may work in the secondary CBD just west of the primary one, and people in the western suburbs may work in the secondary CBD just east of the primary one.
- The primary CBD may not have room to park trains at rush hour without a costly railyard expansion.
- People within the central city may use the line as a rapid transit trunk, to get to either the primary CBD or the two secondary CBDs on the line, as well as to residential neighborhoods not depicted in the diagram.
This is relatively uncontroversial – urban transit is designed along the same guidelines. Also uncontroversial is the question of how far east the commuter line should run: the diagram shows a string of medium-size suburbs, so the line should run as far as the easternmost one, potentially with short-turn runs if the trains at the end are too empty.
The real controversy is how far west to run the service. On the one hand, the secondary city provides a natural outer anchor, with some reverse-peak ridership potential, so there’s an argument for terminating service there. I have criticized the Human Transit model of anchoring as a matter of urban planning, but as a matter of transit planning with fixed urban layout, it is sound; see explanations here and here. On the other hand, there are two smaller suburbs farther west, where people might want to commute to either the primary city or the secondary one, so perhaps service should run farther, with many trains short-turning at the secondary city to avoid running too many empty trains at the western end.
Which of the two options is better – terminating services at the secondary city or continuing onward – depends on the frequency the trunk rail line can support. The reason is that continuing onward requires a very large drop in capacity to avoid empty trains. In the depicted diagram, in relative units, 10% of the western suburbs’ built-up residential area is west of the secondary city; maybe another 10% is the western areas of the secondary city, which could host a station in addition to that at the city’s center. This means that nearly all trains should short-turn; only perhaps one in three or four should continue. If the demand is so intense that a quarter of the base frequency is enough, then trains should continue. But most likely, it isn’t. An individual commuter line with a train every 10 minutes off-peak would be stepped down to every half an hour at the western end, which is borderline; a train every 10 minutes off-peak almost never happens outside Paris, Tokyo, and other enormous systems, except when multiple branches interline to a single trunk.
The alternative is to terminate commuter trains at the secondary city, but then run supplemental service, centered at the secondary city. This supplemental service is not supposed to serve demand into the primary city, handling supercommuters from the western end via a timed transfer (with possible peak through-service), so it can run shorter trains at higher frequency. Sometimes, the secondary city’s CBD must be judged too auto-oriented to be served with commuter rail, and then the correct service pattern is no trains at all west of the secondary city.
In both Providence and San Jose, a situation akin to the above diagram occurs, except without any through-service beyond the primary CBD (respectively, Boston and San Francisco). Of course, San Jose has more residents than San Francisco, 1.03 million compared with 870,000, but it has only 360,000 jobs to San Francisco’s 610,000. Moreover, San Jose’s employment is more dispersed; according to OnTheMap, its CBD’s job density is about comparable to that of Providence’s CBD. Evidently, Caltrain ridership is 13,600 per weekday at San Francisco and 4,200 at San Jose Diridon (PDF-p. 6 here), with both stations located somewhat away from their respective cities’ CBDs. A proper comparison of Providence to Boston is harder to make, since South Station has multiple line and not just the Providence Line, but Providence’s secondary role within New England is well-understood.
In both cities, service runs beyond the secondary city, at reduced frequency. Between San Francisco and San Jose, Caltrain runs 5 trains per hour at the peak, and a train every hour off-peak; but Caltrain also runs three trains per day in each direction south to Gilroy, 47 km to the south (San Francisco-San Jose is 77 km). Between Boston and Providence, a distance of 70 km, the MBTA runs 3-4 trains per hour at the peak and a train every 1.5-2 hours off-peak, but one train per hour at the peak and one train every four hours off-peak continues another 31 km south to Wickford Junction.
Both tails, to Gilroy and to Wickford Junction, are significant drags on the ability of their respective cores to modernize. Ridership is very low: Tamien, just south of San Jose Diridon, has 1,100 weekday riders, but the sum total of all the stations to its south is 559; the two stations south of Providence have between them 454 weekday riders, compared with about 2,300 at Providence and 20,000 on the Providence Line overall (see PDF-pp. 74 and 77 of the 2014 MBTA Bluebook). In both cases, low ridership is a cause of poor service rather than a consequence: Clem Tillier tallied the population and job densities near each Caltrain station and found that, except in the southern neighborhoods of San Jose, there is no real ridership potential on the Gilroy extension; a similar analysis of the Providence Line’s tail has not been carried out, but one of its two stations is in a low-density suburb without many Boston-bound commuters, while Wickford Junction is surrounded by undeveloped land. Caltrain is currently planning to electrify south to Tamien, but there is no justification for continuing electrification further, which means that maintaining Gilroy service would require mixing diesel locomotive-hauled trains with lightweight EMUs; moreover, south of Tamien, the tracks are owned by Union Pacific rather than by Caltrain, and UP has little interest in allowing modern passenger trains on its tracks. In Rhode Island, an additional complication is that the line from Providence down to Wickford Junction is prime high-speed rail territory, and commuter rail ridership is frankly too low to justify complex scheduling with multiple overtakes, unlike the situation farther north in Massachusetts.
In the Bay Area, there is little that can be done, due to the low potential ridership south of Tamien, San Jose’s suburban layout and the distance of Diridon from the CBD, and UP ownership of the tracks. Perhaps a few diesel trains could run to San Jose Diridon with timed transfers to the electrified line from Tamien to San Francisco, but quite likely service could just be canceled. In Rhode Island, Wickford Junction should probably be closed due to low ridership, but Peter Brassard proposed an alternative, a Providence-focused line running short trains at medium frequency (perhaps once every 15 minutes), with very short interstations in order to serve Providence neighborhoods and not just the CBD. Such a line, running at the same average speed as a freight train due to the frequent stops, would interfere heavily with intercity trains, which means that four-tracking the line is a necessary precondition, as discussed here, but this may be worth it given potential local ridership. The most constrained part of the right-of-way is alongside the Route 10 expressway, which requires considerable repairs and is currently being overhauled at high cost.
A number of major cities, most notably London, have designated areas around their built-up areas as green belts, in which development is restricted, in an attempt to curb urban sprawl. The towns within the green belt are not permitted to grow as much as they would in an unrestricted setting, where the built-up areas would merge into a large contiguous urban area. Seeking access to jobs in the urban core, many commuters instead live beyond the greenbelt and commute over long distances. There has been some this policy’s effect on housing prices, for example in Ottawa and in London by YIMBY. In the US, this policy is less common than in Britain and Canada, but exists in Oregon in the form of the urban growth boundaries (UGBs), especially around Portland. The effect has been the same, replacing a continuous sprawling of the urban area with discontinuous suburbanization into many towns; the discontinuous form is also common in Israel and the Netherlands. In this post, I would like to explain how, independently of issues regarding sprawl, such policies are friendlier to drivers than to rail users.
Let us start by considering what affects the average speed of cars and what affects that of public transit. On a well-maintained freeway without traffic, a car can easily maintain 130 km/h, and good cars can do 160 or more on some stretches. In urban areas, these speeds are rarely achievable during the day; even moderate traffic makes it hard to go much beyond 110 or 120. Peak-direction commutes are invariably slower. Moreover, when the car gets off the freeway and onto at-grade arterial roads, the speed drops further, to perhaps 50 or less, depending on density and congestion.
Trains are less affected by congestion. On a well-maintained, straight line, a regional train can go at 160 km/h, or even 200 km/h for some rolling stock, even if headways are short. The busiest lines are typically much slower, but for different reasons: high regional and local traffic usually comes from high population density, which encourages short stop spacing, such that there may not be much opportunity for the train to go quickly. If the route is curvy, then high density also makes it more difficult to straighten the line by acquiring land on the inside of the curves. But by and large, slowdowns on trains come from the need to make station stops, rather than from additional traffic.
Let us now look at greenbelts of two kinds. In the first kind, there is legacy development within the greenbelt, as is common around London. See this example:
The greenbelt is naturally in green, the cities are the light blue circles with the large central one representing the big city, and the major transportation arteries (rail + freeway) are in black. The towns within the greenbelt are all small, because they formed along rail stops before mass motorization; the freeways were built along the preexisting transportation corridors. With mass motorization and suburbanization, more development formed right outside the greenbelt, this time consisting of towns of a variety of sizes, typically clustering near the freeways and railways for best access to the center.
The freeways in this example metro area are unlikely to be very congested. Their congestion comes from commuters into the city, and those are clustered outside the greenbelt, where development is less restricted. Freeways are widened based on the need to maintain a certain level of congestion, and in this case, this means relatively unimpeded traffic from the outside of the green belt right up until the road enters the big city. Under free development, there would be more suburbs closer to the city, and the freeway would be more congested there; travel times from outside the greenbelt would be longer, but more people would live closer to the center, so it would be a wash.
In contrast, the trains are still going to be slowed down by the intermediate stops. The small grandfathered suburbs have no chance of generating the rail traffic of larger suburbs or of in-city stops, but they still typically generate enough that shutting them down to speed traffic is unjustified, to say nothing of politically impossible. (House prices in the greenbelt are likely to be very high because of the tight restrictions, so the commuters there are rich people with clout.) What’s more, frequency is unlikely to be high, since demand from within the greenbelt is so weak. Under free development, there might still be more stops, but not very many – the additional traffic generated by more development in those suburbs would just lead to more ridership per stop, supporting higher frequency and thus making the service better rather than worse.
Let us now look at another greenbelt, without grandfathered suburbs, which is more common in Canada. This is the same map as before, with the in-greenbelt suburbs removed:
In theory, this suburban paradigm lets both trains and cars cruise through the unbuilt area. Overall commutes are longer because of the considerable extra distance traveled, but this distance is traversed at high speed by any mode; 120 km/h is eminently achievable.
In practice, why would there be a modern commuter line on any of these arteries? Commuter rail modernization is historically a piecemeal program, proceeding line by line, prioritizing the highest-trafficked corridors. In Paris, the first commuter line to be turned over to the Metro for operation compatible with city transit, the Ligne de Sceaux, has continuous urban development for nearly its entire length; a lightly-trafficked outer edge was abandoned shortly after the rest of the line was electrified in 1938. If the greenbelt was set up before there was significant suburbanization in the restricted area, it is unlikely that there would have been any reason to invest in a regional rail line; at most there may be a strong intercity line, but then retrofitting it to include slower regional traffic is expensive. Nor is there any case for extending a high-performing urban transit line to or beyond a greenbelt. Parts of Grand Paris Express, namely Lines 14 and 11, are extended from city center outward. In contrast, in London, where the greenbelt reduces density in the suburbs, high investment into regional rail focuses on constructing city-center tunnels in Crossrail and Crossrail 2 and connecting legacy lines to them. In cities that do not even have the amount of suburban development of the counties surrounding London, there is even less justification for constructing new transit.
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.