The MTA’s recent order of 378 R268 cars includes 11 eight-car trains that will be sent to the C line to replace the still-new, 10-car R211 sets that have been running for less than two years.

The new light-rail train, linking Queens and Brooklyn, would signal a shift in the city’s center of gravity, toward one less tethered to the office towers of Midtown.

Hop aboard MARC Penn Line Train 536 for a high-speed ride from Washington Union Station to Baltimore’s Penn Station. This ...