(AP) - Amtrak could prevent New Jersey Transit trains from using its tracks between Trenton and New York if the transit agency doesn't finish installing positive train control.

Amtrak President and CEO Richard Anderson told a House subcommittee on Thursday Amtrak is worried passengers are being put at risk by delays in installing the technology that's designed to prevent crashes.

In a filing to federal regulators this week, NJ Transit reported that through December, the braking system had only been installed in 35 of 440 locomotives and on none of 11 track segments.

New Jersey Transportation Commissioner Diane Gutierrez-Scaccetti said last month that measures were being taken to meet the Dec. 31 deadline.

NJ Transit is the nation's largest statewide public transportation system with more than 200 million passenger trips annually on its trains, buses and light rail.