Also, today black and brown people in the Bronx get to sit on the Lexington trains. A friend who lives in Coop City tells me that the downtown 6 only becomes standing room only at 125th. It’s the white Upper East Siders who have to stand on trains with, gasp, 75% as many riders as they have the capacity for.

The Second Avenue Subway will allow a lot of white people from the Upper East Side to take less crowded trains. But the black and brown people still using the Lexington line will still ride crowded trains.

Back when I voted in favor of a bond issue to build the SAS (in the late 60s iirc), the plan was to push it under the Harlem River into the Bronx. By connecting to the 2, 5, and 6 far upstream, it was going to divert a lot of riders before they even got to the South Bronx stations.

When the currently-under-construction version was approved a few years ago, the City Council decided to go for the truncated all-Manhattan line.

With only two tracks, the SAS would be very limited in its capacity if it ever did reach the Bronx, and so maybe not worth it. And I doubt if they’d link to the IRT lines the way the maps showed back in the ’60s. This SAS, Phase I, is being planned for trains to run on BMT and IND tracks in Midtown, and I’m told that the IRT lines are incompatible.

The line doesn’t connect with the Harlem line to 125th Street; it crosses the Hell Gate Bridge and leads into Penn Station.

The so-called ‘Homeball Alley” section of the ABCD lines north of 125th street actually was built for six tracks between 125th and 145th, although only four tracks are currently used. This means that the T (125th st extension) could turn north and run along with the ABCD lines with very little additional construction cost. (A flyover for the B and T to cross north of 135th street might be all the new construction that is necessary.)

This T train would skip 135th street, use the C platform at 145th street, and continue north along the C line to a terminus at 168th Street, where a connection with the “1″ train would exist.

This routing would provide easy connections from the 1, A-B-C-D lines, and allow the T trains to easily lay up at the yards north of 168th. Since very little new trackage would be required, it would be fairly inexpensive.

The only major new contruction would involve the westward portion of the tunnel from the currently projected T terminus at 125-Park Ave to St. Nicholas Ave. Only one new station would be required, at Malcolm X Blvd, providing a connection with the 2-3 trains.