A number of people have complained to me about crowding on the #7 train at rush hour, and they say it's only getting worse. The MTA has recently added more trains, but they say they're already running as many Well, here's a possible solution that's been floating around for years: widen the trains.
The elevated structures that now support the #7 in Long Island City, Woodside and out to Corona, and the N in LIC and Astoria, were built by the City in 1916 as part of the Dual Contracts with the two major transit companies, the Interboro Rapid Transit Company and the Brooklyn-Manhattan Transit Company. They used to both be connected through the Steinway Tunnel to Times Square and across the Queensboro Bridge to the Second Avenue El. Like most of the els in Manhattan, and like the IRT routes, the platforms were built for trains that were 8.8 feet wide.
The tracks were supposed to be for the benefit of the BMT, and in 1920 the BMT built a tunnel under 60th Street to connect its tracks to Queensboro Plaza. Unfortunately, the BMT trains were 9.75 feet wide and couldn't fit between these platforms, so everyone had to change trains.
In 1942 the City demolished the Second Avenue El, and in 1949 it assigned the Astoria line to the BMT. The platforms were cut back to accommodate the BMT trains, and the 60th Street tunnel was connected to the line. The result was the service pattern that exists today: the 9.75 foot N and W trains from the 60th Street Tunnel go onto the Astoria line, and the 8.8 foot 7 trains from the Steinway Tunnel go onto the Flushing line.
The #7 train currently runs trains with eleven R62A cars. Each car can hold 182 people, for a total of 2002 passengers. If we cut back the platforms on the Flushing Line, the MTA could run trains with ten R160B cars. Each of these can hold 240 people, for a total of 2400 passengers. In other words, switching to B division trains would allow 400 more people to fit on each train.
(P.S. I highly recommend this SubTalk post).