Several commenters, both here and on Streetsblog, have raised a number of points about my proposal to eliminate above-ground Penn Station and reduce the station to a hole in the ground. A few of those points are things I’d already thought about when I wrote that post and didn’t want to clutter; others are new ideas that I’ve had to wrestle with.
On Streetsblog, Mark Walker says, “Getting on a train at Penn is not like using the subway. Instead of a train that runs every five minutes, you’re waiting for a train that runs once per hour (more or less),” implying nicer waiting areas and lounges are needed. My proposal, of course, does not have dedicated waiting areas. (That said, there’s an immense amount of space on the platforms under the escalators, which could be equipped with chairs, tables, and newsstands.)
However, I take exception to the notion that when the train runs every hour, passengers wait an hour. When I lived in Providence, a few trips to Boston, New Haven, and New York taught me the exact amount of time it’d take me to walk from my apartment to the train station: 21 minutes. I learned to time myself to get to the station 2 minutes before the train would leave, and as I recall, I missed the train twice out of maybe 30 trips, and one of those was when I had a lot of luggage and was in a taxi and couldn’t precisely gauge the extra travel time. Walking is that reliable. People who get to Penn Station by subway have to budget some extra time to account for missed subway trains, but from much of the city, including the parts of the CBD not within walking distance from Penn, the required spare time is less than 10 minutes. Moreover, Penn is at its most crowded at rush hour, which is precisely when subway frequency is the highest, and people can reliably time themselves to within less than 5 minutes.
Outlying train stations in Switzerland are deserted except a few minutes before a train shows up, because the connecting transit is all timed to meet the train. This is of course inapplicable at very large stations with many lines, but the modes of transportation that most Penn Station users take to the station are reliable and frequent, if you can even talk of frequency for walking. The result is that the amenities do not need to be extravagant on account of waiting passengers, and do not need to be more than those of a busy subway station in a busy area.
Several commenters raised the idea of shelter. One option, raised by James Sinclair, is an arched glass roof over the station, on the model of Milan. This involves above-ground infrastructure, but the arched structure is only supported at the margins of the compound, which means that the primary feature of a hole-in-the-ground station, the lack of anything that the track area must support the weight of, is still true. I do not think it’s a bad idea; I do, however, want to raise three additional options:
Do nothing. A large proportion of the usable area of the platforms would be located under the walkways above, or under the escalators and staircases. Having measured the depth more precisely, through Plate 14 here, I found it is 13 meters from street level to top of rail, or 12 from street level to platform level, translating to 21 meters of escalator length, plus 2.2-2.5 meters on each side for approach (see page 23 here). About 16 of those 21 (18.5 out of 25.7, counting approaches) meters offer enough space for passengers to stand below the escalators, leading to large areas that could be used for shelter, as noted in the waiting section above.
Build a simple shelter. Stockholm-area train stations have cheap corrugated metal roofs over most of the length of their platforms. These provide protection from rain. Of course those roofs require some structural support at the platform, but because they’re not supposed to hold anything except rainwater, those supports are narrow poles, easy to move around if the station is reconfigured.
Build a street-level glass pane. This may be structurally intricate, but if not, it would provide complete shelter from the elements on the track level, greatly improve passenger circulation, and create a new public plaza. But in summer, the station would be a greenhouse, requiring additional air conditioning.
Note that doing nothing or building a simple shelter would not protect any of the track level from heat or cold. This is fine: evidently, open-air stations are the norm both in cities with hotter summers than New York (Milan is one example, and Tokyo is another) and in cities with colder winters (for example, Stockholm). Passengers are usually dressed for the weather anyway, especially if they’re planning on walking to work from Penn or from the subway station they’re connecting to.
Multiple commenters have said that public art and architecture matter, and building spartan train stations is unaesthetic, representing public squalor. I agree! I don’t think a hole-in-the-wall Penn Station has to be drab or brutalist. It can showcase art, on the model of the mosaics on the subway, or the sculptures on the T-Bana. It can use color to create a more welcoming environment than the monotonous gray of many postwar creations, such as the Washington Metro. The natural sunlight would help a lot.
But more than that, the walkways themselves could be architectural signatures. The best way to build them without supporting them on the track level is some variant on the arch bridge – either the classical arch bridge (which would require three or four spans), or a through-arch. This gives a lot of room to turn the bridges into signature spans. The design work would raise their cost, but short pedestrian bridges tend not to display the same cost structure as massive vehicular ones; the Bridge of Strings, a Calatrava-designed light rail bridge on a line that cost far more to build than light rail should cost, was $70 million for 360 meters. The walkways would not carry light rail, and would be about 140 or 150 meters in span.
Commenters both here (Caelestor) and on Streetsblog (Bolwerk, Matthias, C2check) have brought up transit-oriented development as a reason to allow a tall building on top of the station. With respect, I think on top of a train station is exactly the wrong place to build a tower. Let’s Go LA has an explanation for why the engineering for air rights is so complicated, although he stresses that Penn Station and Grand Central, which were built with the expectation of future high-rise air rights, are exceptions. I’ll add that Penn Station track simplification would also remove many crossovers and switches, making it easier to build air rights. That said, the track spacing is not friendly to the column spacing he proposes.
In New York, the tallest and most expensive recent private-sector office tower on solid ground, the Bank of America Tower, cost around $6,000 per square meter of floor space, in today’s money. Some of the luxury residential towers are more expensive; so are the new World Trade Center buildings, e.g. One World Trade Center was $12,000 per m^2. But the office towers cluster in a specific band of cost, around $2,500 to $5,000 per square meter, with taller towers generally more expensive. The Hudson Yards air rights towers cost in the $10,000-14,000 per square meter range, as much as One World Trade Center. Contrary to Bloomberg’s promises of windfall property tax revenues as his justification for the 7 extension, the city has had to offer tax abatement to encourage developers to build at those prices. Amtrak’s plan for Penn Station South assumes the block immediately south of Penn Station would cost $769 million to $1.3 billion to acquire; when I roughly computed its floor area by counting floors per building, I got 100,000 m^2, which means the price of real estate in that area, $7,700-13,000/m^2, is no higher and may be lower than the construction cost of air rights towers.
In contrast, some sites on firm ground immediately surrounding Penn Station are ripe for redevelopment. The block south of Penn Station, as noted above, has about 100,000 m^2, for a block-wide floor area ratio of 6.7. The Empire State Building’s floor area ratio is 33, so replacing the block with closely spaced supertall towers would require developers to burn just 20% of their profit on acquiring preexisting buildings. To the north of Penn Station, the two sites at 7th and 8th Avenues, flanking One Penn Plaza, are flat; so is nearly all of the western part of the block northeast of Penn, between 33rd and 34th Streets and 6th and 7th Avenues. Eighth Avenue is not developed intensely at all in that latitude – it only becomes important near Times Square. Supertall buildings surrounding Penn Station could even be incorporated into the station complex: railroads using the station might decide to lease offices in some of them, and the exteriors of some of those buildings could incorporate large clocks, some signage, and even train departure boards.
TheEconomist, who has had some truly out-of-the-box ideas, raises a very good point: how to phase the deconstruction of Penn Station in ways that allow service to continue. I don’t have a complete answer to that. Arch bridges, in particular, require extensive falsework, which may complicate matters. However, a general phase plan could consist of knocking down the above-ground buildings, then removing the upper concourse (leaving only the lower), and then removing arms of the lower concourse one by one as the walkways above them are built.
In comments here, people have suggested several alternatives to my proposal to reconfigure Penn Station to have 12 tracks and 6 island platforms between them. There should be 6 approach tracks, as I outlined here: southern approach tracks, combining new Hudson tunnels with a link to Grand Central (which I call Line 2); central tracks, combining the preexisting Hudson tunnels with the southern East River Tunnels (Line 1); and northern tracks, combining the realigned Empire Connection and West Side Yard with the northern East River Tunnels (Line 3).
In my view, each approach track should split into two platform tracks, flanking the same platform. In this situation, there is no need to announce track numbers in advance, as long as the platform is known. Stockholm does this on the commuter lines at Stockholm Central: the northbound lines use tracks 15 and 16 and the southbound lines use tracks 13 and 14, with a platform between each of these track pairs, and until a few minutes before a train arrives, it’s signed on the board as “track 13/14” or “track 15/16.”
The compound looks 140 or 150 meters wide; the maps are unclear about to what extent Penn extends under 31st and 33rd, but according to a diagram Joey shared in comments, it extends quite far, giving 150 meters or even a bit more. Under my proposal, this is enough for 6 platforms of 17 or 18 meters. It sounds like a lot, but it isn’t, especially on Line 3, where Penn Station is the only CBD train station, which implies entire trains would empty at Penn in the morning rush hour. (Line 2, which I expect to be the busiest overall because it’d serve both Penn and Grand Central, is the one I expect to have the least platform crowding problems, precisely because it’d serve both Penn and Grand Central.)
Staircases should be 3 meters wide. Escalators with 1-meter steps have 1.6-meter pits; their capacity is theoretically 9,000 passengers per hour, but practically only 6,000-7,000. Clearing 30 entire trains per hour, filled to seating capacity with 4 standees per square meter of standing space, requires moving about 75,000 passengers per hour. (Per meter of train length, this is comparable to the 4/5 trains and the RER A at their peaks.) With 6 access points, this requires 2 up escalators per access point. The minimum is then 3 escalators, running 2-and-1 at the peak; 4 is better.
In comments, Ari Ofesvit proposes the Spanish solution, which I’ve discussed in previous posts. I’m now convinced it is not the right solution, simply because it compels platforms to be too narrow (about 8.6 meters), which has room for exactly half of what a standard platform twice the width would have, without the possibility of running 4 escalators 3-and-1 at the peak. My comment in that post has more detail, albeit with the assumption that the compound is 140 meters wide.
Fbfree proposes something else: more platforms for intercity trains. Giving intercity trains more platforms (as is done in Stockholm, which has just two approach tracks to the south) gives them more time to dwell; unfortunately, it also narrows the platforms for the regional trains, precisely the ones that can expect the most crowding. Even a single-track platform would take up space out of proportion to the number of passengers it would serve.
Pedestrian throughput is, at the maximum, 81 people per meter of walkway width per minute; this assumes two-way flow, but the numbers for one-way and multiway flow aren’t too different. This is a little less than 5,000 per meter-hour. An escalator bank with two up escalators then needs almost 3 meters of unobstructed platform width on one side (the other side can be used as overflow, but most passengers would use the side of the platform the train discharged them on). This is easy to supply with a 4-escalator bank on a 17-meter platform (there would be 3.8 meters); on an 8.6-meter Spanish platform, there’s only one up escalator per bank, so half the width is required, and is indeed obtainable. But if there are extra platforms for intercity trains, this becomes more strained.
For maximum throughput, it is necessary to minimize separation between escalators on the platform, down to about 6 meters plus approaches, in order to allow wider walkways, which in this case would make the walkways about 25 meters wide. The point here is that the walkways have to have very high pedestrian capacity, since each of them is fed by escalators from all platforms. At 25 meters, the capacity is about 15% less than that of two up escalators per access point (121,500 vs. 144,000), which is fine since some platforms (Line 2 in both directions, Line 3 eastbound in the morning and westbound in the afternoon) would not have so much traffic. But putting in elevators would disrupt this flow somewhat.
I see two ways to increase capacity in the future, if train traffic warrants it: first, build the glass floor/ceiling I outlined above, in the shelter section. This is the simplest possibility. Second, build three more walkways, midway between 7th and 8th Avenues and the two walkways already discussed, and have each walkway or avenue serve only half the platforms – one serving eastbound platforms, one serving westbound platforms. At this point the station would be half-covered by walkways, if they are all about 24 meters wide, but the walkways could be narrowed; as long as they are longer than 15 meters, any passenger arriving on a platform by any of the included access points would be sheltered by the walkway serving platforms in the opposite direction. Elevators should go from each walkway to each platform still, which would facilitate transfers, but the workhorse escalators would spread the load among different walkways.
I’d originally thought that the walkways could host retail and food concessions. The calculation in the preceding section suggests that this wouldn’t be possible, unless the walkways are widened beyond the escalators, with concessions on the outside. Every meter of walkway width would be required for passenger circulation. Even information pamphlets might be restricted to the very edges of the walkways; train departure boards would have to be mounted in the air, for example on the support cables if the through-arch option were chosen for the walkways.
However, there is ample room directly beneath the escalators, staircases, and walkways. With the caveat that escalators of such length need an extra midway support point, they would still have a lot of space underneath: 15-16 meters with sufficient clearance for people to stand comfortably (say, at least 2.5 meters of clearance above); with the upper approaches and the walkways, this is 60-62 meters of largely unobstructed space, for a 60*10 space that could be used in almost any way. Even in the 5-6 meters with less clearance above to the escalator, it’d be possible to use the space at least partly – for example, for sitting, or for bathrooms, the minimum clearance is reduced (I’m writing this post from my apartment, where the ceilings slope down, and the ceiling height above my couch is about 1.5 meters).
There would be two such 60*10 spaces per platform, plus two smaller spaces, near 7th and 8th Avenues, depending on exact placement of access points to the subway. This gives us twelve 60*10 spaces. I doubt that they could ever host high-end concessions, such as full-service restaurants: passengers would probably not go out of their way, to a platform that they weren’t planning on using. This means newsstands could succeed, but not much else; food would have to be shunted to the streets, and presumably restaurants would pay extra to locate right outside the compound. In lieu of concessions, those spaces could host sundry uses, including additional circulation space, information pamphlets, busker performance space, waiting areas for passengers, public art displays, and waiting areas for train crew and cleaners.