The Metropolitan Transportation Authority has big plans for the next few years. New train cars, signal fixes and station upgrades are on the way for New York City’s aging subway system; so are multibillion-dollar projects like the Interborough Express, a proposed rail line between Brooklyn and Queens.

But many of Gotham’s grandest transit ambitions hinge on funding help from the federal government, which has taken an increasingly antagonistic stance toward the city and its vast transportation network.