NEW YORK (CBSNewYork) — After a series of deadly train crashes, Congress mandated all railroads to install new technology to make trains safer by the end of the year.

But the Metropolitan Transportation Authority and NJ TRANSIT said they are not on track to meet the deadline, and improved safety will be delayed.

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The Amtrak train that derailed in Philadelphia in May was traveling 106 mph, more than double the speed limit.

“The most important thing we’re gonna do is we’re gonna deliver positive train control by the end of the year,” Amtrak chief executive officer Joseph Boardman said.

As CBS2’s Matt Kozar explained, positive train control is a system that automatically applies the brakes when a train goes over the speed limit.

Congress mandated railroads to have it installed by December 31, but the MTA and NJ TRANSIT said they’re nowhere close.

“This is enormously complicated technology that used GPS and other tracking systems to know where every single train is on every inch of our network,” MTA spokesman Adam Lisberg said.

Lisberg said logistical issues are causing the delay, not money.

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He said it will take time to put transponders and antennas on 500 miles of track and 1,500 Metro North and LIRR train cars.

“This is the wave of the future. We’re jumping into this with both feet. This is as fast as we can humanly go,” Lisberg said.

A spokesman for NJ Transit said the railroad has faced challenges purchasing radio spectra and coordinating the technology with freight trains that use the same tracks.

Both the MTA and NJ Transit plan to have positive train control fully in place by 2018.

U.S. Sens. Richard Blumenthal (D-Conn.) and Charles Schumer (D-N.Y.) who have advocated for safety on the rails called that unacceptable.

“Federal funds have been allocated to Metro North to implement it, and I’m really disappointed and dismayed that won’t be implemented by 2018 at the earliest, and that deadline is pretty vague,” Blumenthal said.

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In a statement, Schumer said, ‘Congress needs to do everything in its power to hold railroads accountable and help get this system up and running as soon as possible.’