Sunday, November 28, 2010

Subway to New Jersey

We heard on November 16 that the Mayor of New York, the Governor of New York state, and Manhattan real estate interests were all considering the idea of extending the Flushing Line to New Jersey.

This isn't new. For eighty years the east-west tunnel, pointing to New Jersey from its end at Eighth Avenue and 41st St, has sparked the imaginations of railfans and other dreamers. Although the tunnel extension now under construction points down Eleventh Ave to Chelsea Piers, the same thought tickles the brain: why stop there? It's even more tempting right now, while usable tunnel boring equipment is still there at the end of the works.

As the New York Times article put it,
It would extend the New York City subway outside the city for the first time, giving New Jersey commuters direct access to Times Square, Grand Central Terminal and Queens, and to almost every line in the system.
With Governor Christie's recent cancellation of the ARC project still a sore point, the subway extension is being promoted as an alternative way to increase trans-Hudson capacity.

But would it work?

Existing conditions, showing the unfinished subway tunnel to its end. From Google Maps.


Subway lines as a mode of travel fall between the bus line with stops every two or three blocks and the railroad with stops every one or two miles. Following the typical model, an extension of the Flushing Line would look something like this:

- Add the proposed station at Tenth Avenue (41st St).
- 34th St Javits Center station being built.
- Cross the Hudson in a direct path, reaching land at about 9th St (Hoboken).
- Station at Washington St (Hoboken), near the Stevens Institute.
- Station at the cliff, for Palisades Ave (Jersey City) and for transfer to the Hudson Bergen Light Rail at the 9th St / Congress St station.
- Station for Central Ave and Summit Ave (Jersey City).

That's about 2.3 miles from the current end of tunnel at 24th St and Eleventh Ave. For local traffic it would make sense to continue by turning south down the spine of Jersey City, probably under Summit Ave, which would bring it in a few stops to Journal Square.

This would obviously not be an alternative to ARC at all. It would just be the normal type of routing for a subway line.

An extended subway line, with alternatives to Secaucus or Journal Square.

Would it be busy? Yes, I am sure it would. Those parts of Hoboken and Jersey City are densely built urban areas now, and with the new subway they would be ripe for development with taller structures, ruled out now by the capacity of the narrow street system. It would please real estate interests in New Jersey but I don't see how much New York would get out of it.

But after all, the assignment is to go to Secaucus. So continue west, emerge from the hill, and jump across a mile and a half of meadows to Secaucus station. There would be about five stations between Secaucus and Times Square. Travel between local points and both ends would be greatly improved, but for through traffic between New Jersey trains and the east side of Manhattan, it would be slow.

Why do I put up this straw man? Just to show that the plan isn't exactly for a subway extension. Just to show how a subway line would normally be routed and how close stops would normally be.


I think the concept is just to go straight to Secaucus and forget the rest of Hudson County. Times Square to Secaucus with one stop at the prime Manhattan real estate at Hudson Yards.

Just go to Secaucus.

There was some comment about routing via Hoboken, but it wasn't clear whether that meant running to Hoboken Terminal (as some reporters assumed) or just passing under Hoboken. Running via the terminal would add at least two miles to the project.

The concept assumes that Secaucus is the right place to go. I am not so sure. Let's think about where New Jersey Transit trains could go, without ARC. And let's really think about the subway going to Hoboken Terminal and Secaucus.


I haven't seen anything about New Jersey Transit train routings under the new plan. Maybe it's too soon. We can speculate.

The ARC project planned to push about 28 trains an hour through the new pair of tracks. Lines with no Penn Station service would finally get trains to New York, and lines with Penn Station service would get more trains. Reality check: there's a lot more to that than building the tunnel and terminal.

New Jersey Transit official map.


The lines with New York service have already loaded to capacity the two-track "high line" from Kearny to the tunnel entrance. The ARC plan began at Secaucus, but two additional tracks would need to start three miles west of there, and Portal Bridge over the Hackensack would have to be replaced. Governor Christie objected that this expense was not included in ARC funding from the federal government or the Port Authority, even though it would be an integral part of the project. He was right about that.

How will capacity of these lines be increased without ARC?

Additional trains could go to Hoboken. If ARC was going to take 28 trains an hour with a two-track main line, what are the possibilities at Hoboken with its four-track main line and 17 station tracks? Its current peak service is only 23 an hour.

PATH could not possibly support that many more riders. But adding the Flushing Line at Hoboken would triple capacity to Midtown. Fewer than half the peak trains at Hoboken PATH go to 33rd St (the rest go to World Trade Center). Add the full capacity of the subway line.

The terminal itself would need substantial improvements to handle twice the current foot traffic.


The routes without service to New York are all diesel powered.  ARC publicity promised their riders through service with greatly shortened travel time.

ARC however did not include a solution to the power question, and it is a much bigger deal than adding tracks from Kearny to Secaucus. There are about 98 miles of unelectrified route: 28 to Spring Valley, 43 to Suffern by two routes, and 27 to Raritan. Ideally wire would be put up. If this very ambitious project was going to be done in time for ARC, it should have been started already.

The alternative is to develop a practical dual-powered locomotive, something that's been worked on from time to time since the 1950s without ever achieving a totally satisfactory product.

The power question needed to be solved, one way or another, or the trains would not go into the tunnel and the travel time savings would not be achieved. Governor Christie didn't even mention this in his rejection of ARC.

Three of these four routes stop at both Secaucus and Hoboken: Pascack Valley (3 peak hour trains), and Main and Bergen (8 peak hour trains combined). The Raritan Valley Line (4 peak hour trains) ends at Newark Penn, reaching neither Secaucus nor Hoboken.


If Hoboken Terminal can be redesigned to handle ARC-like levels of train traffic, it looks to me like it's a better target for the Flushing subway extension. It wouldn't need to go to Secaucus at all.

Just go to Hoboken Terminal.

Step back. If we don't use Hoboken, how do we increase New Jersey Transit train service?

Where would the additional trains go? The implied answer is Secaucus.

For the Penn Station lines and the diesel-powered Raritan Valley Line, we'd need to add two tracks from Kearny. And then what? The additional trains end at a new terminal station? For the Hoboken diesel lines, would we run extra trains terminating at Secaucus at another new terminal station? These seem like weird solutions.

On the other hand, if all lines have good service to Hoboken:

- The extra tracks from Kearny to Secaucus are not required.
- New platforms and tracks at Secaucus are not required.
- The subway extension can be much shorter, and open sooner.

We do need to substantially upgrade Hoboken Terminal. In the map image above I have the subway crossing the terminal tracks at their west end, with the idea of providing a second access point for every platform at that end.

The approach lines to Hoboken also need to be optimized to maintain more frequent service, but the space is there so that should be possible.

I imagine the number of riders transferring at Secaucus for Penn Station would drop significantly with a more frequent and multi-homed New York connection available at Hoboken. Riders between New Jersey points would probably still save time by not going via Hoboken provided good connections are available at Secaucus. I have not thought through the impact on Secaucus. It would be a political embarrassment to close the station.


None of this means we should not also add two more tracks running to Penn Station.


I have saved for last a problem with the subway that is given little attention.

Images from of Fifth Ave station and Grand Central station.

The three old stations at Times Square, Fifth Avenue, and Grand Central each have just a single island platform between the tracks. The only reason this plan works now is that the Flushing Line has one-way peak traffic, a rarity on the subway. One track at a time has a rush hour load. It's a very efficient use of platform space.

The extension to New Jersey will add a rush hour load to the other track. A second platform will probably be required at all three stations.

Grand Central is about 80 feet below street level in an arched rock tunnel built in the 1890s. There is precedent in the subway itself for adding a side platform to an arched rock tunnel— 191st St— but it is difficult work and will require access tunnels up to mezzanine level. The image above shows the center of the platform. It widens toward the west end.

Fifth Ave is less deep but located under the south side and sidewalk of 42nd St to avoid having the station underpin the shuttle (S) subway. Its narrow profile helped fit it into available space. A side platform would be under either Bryant Park or the shuttle. I think this is the least busy of the three.

Times Square had to cross deep under the Broadway (N Q R) and Seventh Ave (1 2 3) subways, and fit within the narrow limits of 41st St. The routing off 42nd St into 41st (it cuts diagonally under Bryant Park) was probably done to avoid, once again, directly underpinning the shuttle. A side platform would be under the sidewalk at least and might need to cross the building line. The platform is wider than the one at Fifth Ave and has more stairways, and traffic studies may show that it is adequate.

Those three stations might end up killing the plan. For example the M T A vetoed a previous proposal to extend the Flushing line sometime in the 1990s. The New York Times, Nov 23, reported:
Back then, the transportation authority argued that the subway station at Grand Central Terminal was at full capacity and could not practically be expanded to accommodate thousands of commuters from across the Hudson.


Postscript 1:

I wrote all this and then found another similar plan here to run the subway to Hoboken Terminal. But the writer has changed his mind this past week:
Digging to Secaucus makes more sense than going to Jersey City. Secaucus is already a giant transfer station for trains that don’t go into Manhattan.
I disagree. It is a transfer station only for trains that also go to Hoboken. Going to Secaucus would make the subway extension miles longer, and New Jersey Transit trains that now end at Hoboken or Newark Penn would need to go to Secaucus instead to take advantage. Essentially you'd be building a new Hoboken Terminal in the middle of nowhere, and begging construction of a new transit line from there to reach Jersey City and lower Manhattan. I don't see any advantage to it.

Postscript 2:

And then I saw Bob Prevedi in The Record reading my mind on November 24:
To truly double capacity and make full use of the No. 7 line would require extending two tracks for NJ Transit trains and building a better terminal at Secaucus to allow more service between Newark to Secaucus – otherwise the No. 7 Subway extension would not realize the increase in capacity that everyone is looking for.

On the other hand, Hoboken Terminal does have the facilities already to handle more NJ Transit trains and riders – which makes it the logical location for the No. 7 line to end up in. [...]

The only real issue would be platform crowding at Grand Central, which would require more stairs to be constructed. [...]

By making the most use of our existing resources of the Hoboken Terminal and the No. 7 subway, we minimize the capital expense by digging only two miles instead of four to Secaucus and another four to Newark, and meet the growing needs on both sides of the Hudson River.

Great minds... what can I say?


  1. Interesting that you mention the dual-mode power. I had no idea this was tied to the ARC fiasco. Think they'll kill the ALP-45DP as a result? Montreal's AMT is counting on being able to tag on to the order.


  2. I overlooked that dual-power engines are already on order. They could be used at least on the nominal Penn Station - Bay Head runs, where passengers actually have to change trains at Long Branch. And maybe some Penn Station - Dover runs could continue west. But while these uses would be nice they are hardly essential. I wonder whether Christie knows about them.

  3. The tunnels as bored out would end just about West 25th Street in Manhattan. This is to allow for the line to terminate at 34th Street (Javits Center), and then to have a turnaround area, storage area and overrun (and ventilation plant south of the end of track, at the end of the tunnels). If the line were extended, it would run SOUTH at first, which makes sense since this allow for a very gentle grade as the line descends down below the silt line, and then turns gently westward to cross the Hudson.
    A shell for a 23rd Street station could be built here, as well as maybe a shell for a 14th Street station, before the line finally turns westward toward Hoboken. I'm fairly certain that the "local" stops at 23rd and 14th Streets would not be a very popular idea.
    So let's scratch this and say that the line simply descends southward, turns westward and goes toward Hoboken. It either enters Hoboken at the north end (near the border with Weehawken) and then continues to a terminus at the PATH/NJT station in south hoboken, or the first stop is in (central) Hoboken near Stevens. Either way, it means great service for those living in northern Hoboken as well as a convenient transfer to the Hudson-Bergen Lightrail. If you would like service to Secaucus or even Rutherford, look to extension of the Hudson-Bergen light rail line!