Subway investments can include expansion of the map of lines, for example Second Avenue Subway; proposals for such extensions are affectionately called crayon, a term from London Reconnections that hopped the Pond. But they can also include improvements that are not visible as lines on a map, and yet are visible to passengers in the form of better service: faster, more reliable, more accessible, and more frequent.

Yesterday I asked on Twitter what subway investments people think New York should get, and people mostly gave their crayons. Most people gave the same list of core lines – Second Avenue Subway Phase 2, an extension of the 2 and 5 on Nostrand, an extension of the 4 on Utica, an extension of the N and W to LaGuardia, the ongoing Interborough Express proposal, and an extension of Second Avenue Subway along 125th – but beyond that there’s wide divergence and a lot of people argue over the merits of various extensions. But then an anonymous account that began last year and has 21 followers and yet has proven extremely fluent in the New York transit advocacy conversation, named N_LaGuardia, asked a more interesting question: what non-crayon systemic investments do people think the subway needs?

On the latter question, there seems to be wide agreement among area technical advocates, and as far as I can tell the main advocacy organizations agree on most points. To the extent people gave differing answers in N_LaGuardia’s thread, it was about not thinking of everything at once, or running into the Twitter character limit.

It is unfortunate that many of these features requiring capital construction run into the usual New York problem of excessive construction costs. The same institutional mechanisms that make the region incapable of building much additional extension of the system also frustrate systemwide upgrades to station infrastructure and signaling.

Accessibility

New York has one of the world’s least accessible major metro systems, alongside London and (even worse) Paris. In contrast, Berlin, of similar age, is two-thirds accessible and planned to reach 100% soon, and the same is true of Madrid; Seoul is newer but was not built accessible and retrofits are nearly complete, with the few remaining gaps generating much outrage by people with disabilities.

Unfortunately, like most other forms of capital construction in New York, accessibility retrofits are unusually costly. The elevator retrofits from the last capital plan were $40 million per station, and the next batch is in theory $50 million, with the public-facing estimates saying $70 million with contingency; the range in the European cities with extensive accessibility (that is, not London or Paris) is entirely single-digit million. Nonetheless, this is understood to be a priority in New York and must be accelerated to improve the quality of universal design in the system.

Platform screen doors

The issue of platform screen doors (PSDs) or platform edge doors (PEDs) became salient earlier this year due to a much-publicized homicide by pushing a passenger onto a train, and the MTA eventually agreed to pilot PSDs at three stations. The benefits of PSDs are numerous, including,

• Safety – there are tens of accident and suicide deaths every year from falling onto tracks, in addition to the aforementioned homicide.
• Greater accessibility – people with balance problems have less to worry about from falling onto the track.
• Capacity – PSDs take up platform space but they permit passengers to stand right next to them, and the overall effect is to reduce platform overcrowding at busy times.
• Air cooling – at subway stations with full-height PSDs (which are rare in retrofits but I’m told exist in Seoul), it’s easier to install air conditioning for summer cooling.

The main difficulty is that PSDs require trains to stop at precise locations, to within about a meter, which requires signaling improvements (see below). Moreover, in New York, trains do not yet have consistent door placement, and the lettered lines even have different numbers of doors sometimes (4 per car but the cars can be 60′ or 75′ long) – and the heavily interlined system is such that it’s hard to segregate lines into captive fleets.

But the biggest difficulty, as with accessibility, is again the costs. In the wake of public agitation for PSDs earlier this year, the MTA released as 2019 study saying only 128 stations could be retrofitted with PSDs, at a cost of $7 billion each, or $55 million per station; in Paris, PSDs are installed on Métro lines as they are being automated, at a cost of (per Wikipedia) 4M€ per station of about half the platform length as in New York.

Signaling improvements

New York relies on ancient signaling for the subway. This leads to multiple problems: maintenance is difficult as the international suppliers no longer make the required spare parts; the signals are designed around the performance specs of generations-old trains and reduce capacity on more modern trains; the signals are confusing to drivers and therefore trains run slower than they can.

To modernize them, New York is going straight to the most advanced system available: CBTC, or communications-based train control, also known as moving-block signaling. This is already done on the L and 7 trains and is under installation on other lines, which are not isolated from the rest of the system. CBTC permits much higher peak capacity in London; in New York, unfortunately, this effect has been weaker because of other constraints, including weak electrical substation capacity and bumper tracks at the terminals of both the L and the 7.

Moreover, in New York, the L train’s performance was derated when CBTC was installed, to reduce brake wear. The effect of such computer control should be the opposite, as computers drive more precisely than humans: in Paris, the automation of Line 1 led to a speed increase of 15-20%, and CBTC even without automation has the same precision level as full automation.

As before, costs form a major barrier. I can’t give the most recent analogs, because such projects tend to bundle a lot of extras, such as new trainsets and PSDs in Paris. In Nuremberg, the first city in the world to permanently convert a preexisting metro system to driverless operations, the cost of just the driverless system is said to have been 110M€ in the late 2000s, for what I believe is 13 km of U2 (U3 was built with driverless operations in mind, and then U2, from which it branches, was converted). It is said that automating U1 should cost 100M€ for 19.5 km, but this project is not happening due to stiff competition for federal funds and therefore its real cost is uncertain. In contrast, Reinvent Albany quotes $636 million for the 7 train in New York, of which $202 million must be excluded as rolling stock conversion; the Flushing Line is 16 km long, so this is still $27 million/km and not the $7-12 million/km of Nuremberg.

Maintenance regime

The maintenance regime in New York involves heavy slowdowns and capacity restrictions. Trains run 24/7 without any breaks for regular maintenance. Instead, maintenance is done one track at a time during off-peak periods, with flagging rules that slow down trains on adjacent tracks and have gotten more onerous over the last 10-20 years; only recently have planners begun to use temporary barriers to reduce the burden of flagging.

The result of this system is threefold. First, track maintenance productivity is extremely low – the train on an adjacent track slows down as it passes but the work stops as it passes as well. Second, speeds are unreliable off-peak and the timetable is in perpetual firefighting mode. And third, parts of the system are claimed to be incapable of running more than about 16 trains per hour off-peak, which means that if there is any branching, the branches are limited to 8, which is not enough frequency on a major urban metro system.

It takes a small amount of capital spending to increase efficiency of maintenance, through procuring more advanced machinery, installing barriers between tracks, and installing crossovers at appropriate locations. But it takes a large degree of operations and management reform to get there, which is necessary for reducing the high operating costs of the subway.

Deinterlining

New York has the most complicated interlining of any global metro network. Only four lines – the 1, 6, 7, and L – run by themselves without any track sharing with other lines. The 2, 3, 4, and 5 share tracks with one another. Then the lettered trains other than the L all share tracks on various segments, without any further segregation. Only some commuter rail networks are more complex than this – and even Tokyo has greater degree of segregation between different trunk lines, despite extensive through-service to commuter rail. The New York way guarantees more direct service on more origin-destination pairs, but at low frequency and with poor speed and reliability.

London, the second most interlined system, has long wanted to reduce interlining to increase capacity. The Northern line traditionally had just one southern segment reverse-branching to two central trunks, combining and splitting into two northern branches. When CBTC opened, the busier of the central trunks got 26 peak trains per hour; the more recent Battersea extension removed the interlining to the south, permitting boosting capacity up to 32 tph, and full deinterlining to the north would boost it to 36 tph, as on the most captive Underground lines.

In New York, it is desirable to remove all reverse-branching. At DeKalb Avenue in Downtown Brooklyn, the interlocking switches the four express (bridge) tracks from an arrangement of the B and D on one track pair and the N and Q on the other to the B and Q on one track pair and the D and N on the other; the process is so complex that every train is delayed two minutes just from the operation of the switches. Everywhere within the system, interlining creates too much dependency between the different trains, so that delays on one line propagate to the others, reducing reliability, speed, and capacity.

Some of the problem is, as usual, about high costs. Rogers Avenue Junction controls the branching of the 2, 3, 4, and 5 trains in Brooklyn, transitioning from the 2 and 3 sharing one track pair and the 4 and 5 sharing another to the 3 and 4 running on dedicated tracks and the 2 and 5 sharing tracks. For a brief segment, the 2, 3 and 5 trains all share tracks. This devastates capacity on both trunk lines, which rank first and third citywide in peak crowding as of the eve of the opening of Second Avenue Subway. There are already internal designs for rebuilding the junction to avoid this problem – at a cost of $300 million.

But some of the problem is also about operating paradigms. New York must move away from the scheduling ideas of the 1920s and 30s and understand that independently-operated lines with dedicated fleets and timetables, with passengers making transfers as appropriate, are more robust and overall better for most riders. DeKalb can be deinterlined with no capital spending at all, and so can Columbus Circle. It’s Rogers and Queens Plaza where spending is ideal (but even then, not strictly required if some operational compromises are made), and the 142nd Street Junction in Harlem where an extensive rebuild is obligatory in order to permit splitting the 2 from the 5 in the Bronx permanently.

Labor changes

Staffing levels in New York are very high. Trains have conductors and not just drivers; this is not globally unheard of (Toronto and some lines in Tokyo still have conductors) but it’s rare. With good enough signaling, a retrofit even for full automation is possible, as in Nuremberg, Paris, and Singapore. Maintenance work is likewise unproductive, not because people don’t work hard, but because they work inefficiently.

Improving this situation involves changes on both sides of the ledger – staffing and service. Conductors have to be cut for efficiency and not all of them can be absorbed by other roles, and the same is true of some station facilities and maintenance functions. In contrast, the low productivity of drivers in New York – they spend around 550 hours a year driving a revenue train whereas Berlin’s drivers, who get 6 weeks of annual paid vacation, scratch 900 – is the result of poor off-peak frequency, and must be resolved through increases in off-peak service that increase efficiency without layoffs.

Ultimate goal: six-minute service

I wrote two years ago about what it would take to ensure every public transit service in New York runs every six minutes off-peak, calling it a six-minute city.

Riders Alliance argues for the same goal, with the hashtag #6minuteservice; I do not know if they were basing this on what I’d written or if it’s convergent evolution. But it’s a good design goal for timetabling, with implications for labor efficiency, maintenance efficiency, the schedule paradigm, and the bus system.

No tradeoffs

It is fortunate that the agenda of systemwide improvements does not exhibit significant tradeoffs in investment. Other parts of the transit agenda do not need to suffer to implement those improvements. On the contrary, they tend to interact positively: accessibility and PSDs can be combined (and federal law is written in such a way that PSDs void the grandfather clause permitting the subway to keep most of its stations inaccessible), faster and more reliable trains can be run more frequently off-peak, better service means higher ridership and therefore higher demand for extensions. Only the issue of labor exhibits a clear set of losers from the changes, and those can be compensated in a one-time deal.

Moreover, the budget for such an agenda is reasonable, if New York can keep its construction costs under control. At the per-elevator costs of Berlin or Madrid, New York could make its entire network wheelchair-accessible for around $3.5-4 billion. Parisian PSDs, pro-rated to the greater size of New York trains, would be around $10 million a station, or $5 billion systemwide. Full automation at German costs would be maybe $6 billion with triple- and quad-track lines pro-rated. The entire slate of changes required for full deinterlining, including a pocket track for the 3 train at 135th Street, a rebuild of the 36th Street station in Queens, and a connection between Queensboro Plaza and Queens Plaza, should be measured in the hundreds of millions, not billions.

The overall program still goes into double-digit billions; it requires a big push. But this big push is worth two to three years’ worth of current New York City Transit capital spending. A New York that can do this can also add 50-100 km to its subway network and vice versa, all while holding down operating costs to typical first-world levels. For the most part, the planners already know what needs to be done; the hard part is getting construction costs to reasonable levels so that they can do it on the current budget.