Between New York and New Haven, a distance of 120 km (from Penn Station) or 116 km (from Grand Central), the two fastest intercity trains of the day take 1:35 to travel, an average of 75 km/h. Most do the trip in about 1:40, averaging about 72 km/h. Commuter trains to Grand Central do it in about 1:40 three times a day, averaging 70 km/h, but the vast majority of even the rush express trains are slower, a few doing it in 1:52 and most in about two hours, averaging 58 km/h. This is not normal for a primary intercity corridor; the Acela averages about 120 km/h between New York and Washington and between New Haven and Boston, which is typical for non-high-speed intercity lines in Europe, while high-speed ones usually average 200 km/h or more. I’ve been asked by some big names in online transit content creation why this is so, and hope to explain why the trains are slow, and what it would take to reduce 40 minutes from the one-way trip time.

The contrast should be with the high-speed rail proposal that I’m working on at Marron, which cuts the intercity trip time between New York and New Haven to about 52 minutes, on the existing right-of-way, and the express commuter rail trip time to Grand Central to about 1:16. The result is not high-speed rail, but is a fast upgraded intercity rail line, on a par with the faster British and Swedish lines. Changes in right-of-way geometry, including buyouts of houses in expensive suburbs in Connecticut, could reasonably cut the intercity trip time to about 45 minutes; these are mapped here, the 52-minute trip corresponding to the alternatives that stay on the existing right-of-way and the 45-minute one to the alternatives that use the bypasses where they exist.

The primary culprit for the slow trip times today is poor scheduling practices. Those practices, in turn, come from mutual abuse between Amtrak and the commuter rail operators, in this case Metro-North and the Connecticut Department of Transportation, both of which display terminal incompetence on all matters related to rail. The state of the tracks contributes to the slowness, and thus the second most important issue is poor maintenance practices leading to unreliable infrastructure, which then feeds into poor scheduling. Metro-North and CTDOT are again especially bad even by American standards. Physical infrastructure problems add minutes here and there, but the most important interventions are cheap and for the most part can only work with better timetabling rather than on their own.

Of note, it is common to blame the low speeds on curves. However, the curves are not especially onerous – few restrict trains to slower speeds than about 150 km/h given good operating practices. In fact, the Northeast Corridor gets if anything curvier east of New Haven until after it crosses into Rhode Island, but the speed there is higher, as there is less dense commuter traffic complicating the schedule, and Amtrak’s level of incompetence is bad but less bad than that of CTDOT.

Timetable padding

Every rail timetable has to include contingency or buffer time. This takes into account primarily the need for trains to recover from delays, and secondarily suboptimal driver behavior, such as starting to brake a little too early. Switzerland pads its timetables 7%; the TGV network can only do about 10-13%, and the ICE network about 25%. What I and others have seen on Amtrak and Metro-North trains as well as what train drivers have told me suggests that the buffer time between New York and New Haven is 25% or even maybe 30%.

More complex networks require more padding, since delays on one train cascade to others. The ICE network mixes intercity trains together with much slower regional ones on the same tracks, all over Germany, and delays can cascade across the entire country, to the point that some people have begun to advocate that Germany build a separate high-speed rail network, not for speed (which activists here don’t care much about), but for the reliability of having a fast network and a slow network rather than one mixed network. The more segregated TGV network thus does better; the almost entirely dedicated-track Shinkansen system does even better, and JR East suggested 4% padding in its review of California High-Speed Rail. Switzerland is like Germany in having a single mixed-speed network, but it has more systematic processes for avoiding delays, such as strategic investment in bypasses around known bottlenecks.

The Northeast Corridor is not an especially complex network. It is a single line with branches, rather than a two-dimensional mesh like the German rail network. There is little freight traffic, which makes it possible to control freight through regular slots, with the number of potential slots greatly exceeding actual traffic so that if a train misses its slot, it can wait 10 or 15 minutes for the next one. Passenger traffic is high on all lines serving the corridor, and thus there is no need to cut corners on reliability (such as signals, or platforms) on any of the branches. It is a mixed-speed line, but nearly all of it has four tracks, and where commuter trains share tracks with intercity trains, they run express and the speed difference is not large. In the timetables we developed at Marron with Devin Wilkins, express commuter trains do Stamford-Grand Central in 28 minutes if they run as today, stopping only at Harlem-125th, and in 29 if they also stop at New Rochelle; intercity trains do Stamford-Penn Station in 25 minutes, on a marginally longer route into New York. Slotting intercity and express commuter trains on the same tracks between Stamford and New Rochelle is annoying, but is not an objectively hard scheduling problem.

This does not mean that Amtrak and Metro-North could just shave minutes off of the existing timetables, change nothing else, and run trains to the faster schedules. Other elements of the schedule would make the trains too unreliable. But it is possible to realign the schedules appropriately and cut the trip time by a factor of about 1.3/1.07 = 1.2.

Timetable complexity

The ideal schedule is one with as few variations as possible. This way, planners can write one schedule, ensure that it works, and, if there are problems with it, then develop an infrastructure program that builds around the bottlenecks. Switzerland, as usual, sets the standard, with its all-day repeating clockface timetable, or Takt. Swiss trains repeat regularly every hour, and on the busy lines every half hour; planners need to make sure one pattern works and then repeat it all day. It’s the planning equivalent of economies of scale in manufacturing.

New York planning, relative to the ideal, represents the list of what not to do, and it’s worse on busier lines such as the New Haven Line than on less busy lines. In effect, the New Haven Line schedule is the planning equivalent of rules for writing prose that illustrate each rule by breaking it – remember to not split infinitives, the passive voice should be avoided, eschew obfuscation, and so on – except that it is meant to be taken seriously. It has all of the following problems:

1. Where good planning begins with one peak hour and repeats it all day, the New Haven Line has few repeating patterns, and practically none at the peak.
2. Where good planning aims to have trains make consistent stops for legibility and for ease of planning around bottlenecks, the New Haven Line has bespoke stopping patterns – not counting branches, there are 16 trains entering Grand Central at the peak hour, which make 13 distinct stopping patterns.
3. Where good regional rail planning keeps the peak-to-base ratio low – Switzerland is almost 1:1, and even very large cities that need a huge volume of commuter trains at rush hour like Paris or Tokyo do not exceed 2:1 (and London is well below it) – the New Haven Line has, with branches, 20 trains entering Grand Central at the peak hour and 4 entering each off-peak hour.
4. Where good planning runs more or less the same service on weekends as in the off-peak on weekdays, the New Haven Line’s midday off-peak and weekend schedules are different even as they run the same number of trains (two express and two local per hour).
5. Where good planning aims to use the timetable for a prolonged period of time to reduce the need to redo the schedule, for example updating annually as in Switzerland, New York-area practice is to update several times a year, in what looks like a 3-6 month period.
6. Where good planning keeps the trains spaced far enough based on signal system constraints by default, Metro-North timetables somehow have trains on the shared trunk between Harlem and Grand Central sometimes arriving within less than the 2 minute minimum on the same track, requiring special speed restrictions, even with unimpressive traffic levels by urban commuter rail trunk standards.
7. Where good maintenance is done when trains are not running, that is, at night, in order to avoid disturbing weekday traffic, American planning assumes that daytime maintenance will always take some track out of service; the New Haven Line’s track renewal program has been so mismanaged that at no point since it began in the 1990s have all four tracks between New York and New Haven been operable along the entire line – some section is always shut down. Daytime maintenance is also a problem in Germany, and is a factor behind the poor schedule reliability here.

The constant tweaks to the timetable are also a feature of the New York City Subway, with its substantially simpler stopping patterns. There, the services are consistent, and change at a rate of a handful per decade (most recently, when Second Avenue Subway opened; the previous time was during the 2010 service cuts). However, frequency is micro-targeted based on crowding guidelines, so the planners never have time to optimize one schedule; moreover, with 24/7 service, daytime closures for maintenance are unavoidable. This way, where planners at healthy railroads write schedules, planners at American passenger railroads write service changes. The New York City Subway at least has the partial excuse of 24/7 service; Metro-North has no such excuse. The maxim that the Northeast Corridor is held together with duct tape, and is managed by people who are unfamiliar with any more advanced tools than duct tape, also applies to timetabling.

In contrast with today’s morass, the schedule we’ve been writing aims to simplify whenever possible. Branches are slotted into windows that could be used by local or express main line trains depending on the desired service pattern. From New Haven south, everything is on a repeating 10-minute Takt. The New Haven Line is reduced to four stopping patterns – local Stamford-Grand Central, local Stamford-Penn Station, express New Haven-Grand Central, intercity New Haven-Penn Station – each running every 10 minutes. It took weeks to find a pattern that worked with all the constraints of the right-of-way and allowed some future desired infrastructure changes, and even that required some track changes detailed below. Off-peak, the commuter train patterns could run every 20 minutes instead, using every other slot; the timetable should not be tweaked further.

It is particularly important to avoid timetable complexity beyond local and express trains east of Stamford. The line has four tracks, and could be run with commuter trains on the local tracks, making all stops before transitioning to the express tracks at Stamford, and intercity trains on the express tracks, running nonstop between Stamford and New Haven. In theory, this means this section could be run with less than 7% schedule padding, for example the Shinkansen’s 4%, but in practice, I suspect it cancels out with the more complex situation between Stamford and New Rochelle, so 7% is the best that can be squeezed with maximally simple schedules.

Speed zones and curves

The New Haven Line is rather curvy, having been built in the 1840s. But its speed limits are still too low for its curves. I wrote here about cant and cant deficiency, and am not going to repeat myself too much. But, in brief, the speed on curves is governed by the formula

where v is speed, a is lateral acceleration in the horizontal plane, and r is curve radius. The value of a is usually expressed not in units of acceleration, but in units of distance, scaled so that, on standard-gauge track, 150 mm (of cant) correspond to 1 m/s^2 lateral acceleration. Typical maximum regulatory limits on cant range between 160 and 180 mm; the US permits 7″, but nowhere is more than 6″ used, and the New Haven Line’s curves mostly range between 3″ and 5″ cant. Cant deficiency limits depend on the train – regular passenger trains typically do 130-150 mm at the relevant speeds, but in the US, the normal practice is to limit commuter trains to 3″ cant deficiency, and only use 5″ on Amtrak Regional trains (the Acela tilts and is capable of 7″ today, with the new trains rated for 9″).

The curves on the New Haven Line are, for the most part, built to a standard of 2° radius, or, in metric units, r = 873. The most aggressive common cant and cant deficiency limits, 180 and 150 mm respectively, allow a = 2.2, and thus v = 43.82 m/s = 157.77 km/h; our timetables limit commuter trains to 150 km/h, and there are surprisingly few curves with tighter limits. In contrast, current practice restricts a to about 1.2, which means trains take the same curves at a speed of about 116 km/h, which is rounded down to 70 mph.

The slowdowns also affect intercity rail more than is required. While Amtrak trains are cleared for 5″ cant deficiency, Metro-North prefers to timetable all trains at its own trains’ speed on curves. Then, because there are so few opportunities under current standards for trains to run faster than 70-75 mph within CTDOT territory, the entire line from the state line to New Haven is maintained to those standards, and thus even on relatively straight sections, there is no opportunity to gain speed. East of New Haven, the curves are if anything tighter, but Amtrak dominance means the tracks are cleared for 100-125 mph, cant is higher, and cant deficiency is higher as well.

All of these restrictions can be lifted. The work required to redo a line from 110 km/h to 160 km/h or even more is rather routine, as long as it can be done within the right-of-way. The standards for track irregularity get tighter as speed increases, but all of this can be handled with track laying machines, which use the track itself to do the work, at a pace of about 0.5 km/h, or about 1.5 km in a three-hour nighttime work window; the entire New Haven Line can be regraded in about a year this way.

Unfortunately, Metro-North is used to manual track inspections rather than modern machinery. It finally bought a track laying machine on the model of Amtrak, but appears not to use it very well; the productivity I hear quoted is one tenth what was expected. But what is hard for Metro-North and CTDOT is not objectively hard, and even other Northeastern American railroads are often capable of it.

Supportive infrastructure

Infrastructure construction and timetabling work in tandem normally. Swiss practice is to use insights from the timetable in theory and in practice to inform where to build new tracks. American practice does no such thing – for one, Metro-North is allergic to systematic track improvement, so over the generations, the timetable has diverged from the infrastructure that could support it.

In fact, a very high-frequency peak schedule requires eliminating at-grade conflicts whenever it is even remotely feasible. Shell Interlocking at CP 217, just south of New Rochelle, is a flat junction on which trains from the north can go to either Grand Central or Penn Station. Grade-separating the junction was occasionally on the wishlist for Northeast Corridor improvements, but Metro-North is not currently asking for it, even though it is especially important as Penn Station Access is about to open. The junctions with the branches farther north – New Canaan, Danbury, Waterbury – are flat as well, for which the solutions can be a forced transfer (as is sometimes practiced with Waterbury, the weakest of the three) or grade-separation. This does not cost a large amount of money – New Jersey Transit is applying for money for its equivalent of Shell, Hunter Flyover connecting the Raritan Valley Line to the Northeast Corridor, and the budget is $300 million in the plan and, I’ve been told, $400 million with recent inflation and perhaps some small cost overrun.

Then there is the issue of the Grand Central approaches. The current throat limits trains to 10 mph on the last mile into the station. In other words, the last mile takes six minutes. It should take about two, based on actual throat and turnout geometry; the turnouts are #12 until around 700 meters from the end of the platform, and in Germany, a 1:12 switch is 60 km/h, and closer to the platforms, the turnouts are #7 and (on one cluster of tracks) #6.5, where in a Germany, a 1:7 is 40 km/h. Even with bumper tracks, the last mile has no reason to take longer than two minutes, saving all Metro-North travelers to Grand Central four minutes. The turnouts would need to be regraded to tangential standards, but this can be done within their existing footprint; the cost of a new turnout in a selection of European countries and also on American freight railroads is around $250,000 in the prices of the 2010s, whereas Metro-North’s switches cost perhaps five times much in the same era.

Finally, the movable bridges impose certain speed restrictions. Those are the biggest projects currently in planning for speeding up the New Haven Line. In truth, the slowdowns imposed are secondary (though our timetables still assume they are fixed). They are also extremely expensive – one of them is currently slated for in situ replacement for $1 billion, for a span of 220 meters from tower to tower, on a river about 100 m wide. CTDOT rail projects are generally absurdly expensive even by American standards – infill stations on the Hartford Line are coming in at $50 million or more, twice the cost of suburban Boston and more than twice that of suburban Philadelphia – for which the culprit must be poor project management and lack of in-house expertise.

Conclusion

The New Haven Line is a busy railroad at the peak, but nothing about it is special. It is old, but no older than faster sections of the Northeast Corridor or fast legacy intercity main lines in parts of Europe, especially the United Kingdom. It is busy, but its total ridership is unimpressive by European S-Bahn standards – the single trunk line in Munich with its seven branches on each side generates about 900,000 daily riders, perhaps a bit more than all three New York-area commuter railroads combined. It is branched, but the branching is simpler than on the busier systems, and the graph of the Northeast Corridor overall is acyclic, simplifying planning.

The reason the trains are slow is not the infrastructure. The elements of the infrastructure that need to be fixed to shorten the trip times from about 1:35 intercity and 2:00 commuter to 0:52 intercity and 1:16 commuter are cheap. Rather, the reason is that the line is managed not just by Americans, which is usually bad enough, but specifically by Metro-North and CTDOT. The schedules are designed not to work; the maintenance is designed not to work either and is too expensive.