What subway do you take from 48th Street in Manhattan to Bedford Avenue in Brooklyn?

Take the Uptown 1 train (of the 1-2-3, the red line), or the Uptown 2 late nights, from Canal Street (at Varick Street) or Houston Street (on Varick Street between King and Houston Streets) to 14th Street (at 7th Avenue).

Walk through the tunnel that connects the 14th Street Station-7th Avenue Station on the 1-2-3 to the 14th Street-6th Avenue Station.

At the 14th Street-6th Avenue Station, transfer to the Brooklyn-bound L train (the grey line) to Bedford Avenue. Bedford Avenue is the first stop in Brooklyn. It's the next stop after 14th Street-1st Avenue.