Subway Construction Set

1.     Subway background

Generally, there are two types of subway track, double-tracked and quadruple-tracked. Double-tracked is used mainly for “local” lines, where trains stop at every station. Quadruple-tracked is used for “express” lines, where some trains will stop at every station, and some do not. It is possible on express lines to have stations with only local stops, or both local and express stops. There will usually be a few local stations between express stops, however there are prototypical exceptions to this. Single track is used primarily for connections from one line to another and where routes diverge. Since all NYC Subway lines are point-to-point routes (with the occasional exception of the Rockaways Wye and South Ferry & non-revenue City Hall loops), allowing a place for trains to cross over to tracks running in the opposite direction near the end of each line is usually required. Crossovers from express to local tracks (and vice-versa) are also common, especially prior to where other lines diverge from a common trackage. Many express routes only run during rush hours, or daytime, and run off-peak as local service. While not necessary, designing your route with such crossovers will increase your operational capabilities.