New York, NY —

The MTA says a new federal law is forcing it to spend $700 million over the next five years to install an automatic braking system on commuter rail roads. WNYC's Matthew Schuerman has more.

REPORTER: After a train crash last September killed twenty-five people north of Los Angeles, the federal government required freight and passenger rail roads around the country to implement something called "positive train control". That term refers to safety systems that prevent collisions, such as emergency brakes that get tripped if an engineer ignores a track signal.

Congress appropriated $50 million to fix the problem nationwide. But the MTA alone says it'll need $700 million to implement a system on the Long Island Rail Road and Metro North. That's as much as the two commuter lines will spend on new train cars over the next five years.

The MTA supports the law, though it hopes Washington will offer more funding. The Association of American Railroads takes a harder line, calling it an unfunded mandate with questionable safety benefits. For WNYC, I'm Matthew Schuerman.