The MBTA announced Monday it had received approval from the Federal Railroad Administration to extend the deadline for the full positive train control program to December 2020. 

Positive train control is a federally mandated safety control system that automatically decreases train speeds when needed, reducing train collisions and preventing human error.

The MBTA previously had a December 2018 deadline. 

Work to install positive train control infrastructure on the MBTA commuter rail network is in various stages of completion and testing on each line. On the North Shore, work was done on the Newburyport/Rockport line during the weekend commuter rail shutdown in the summer of 2017. 

“Positive train control is without question the most significant investment we are making to upgrade the safety of our commuter rail system,” MBTA General Manager Steve Poftak said in a prepared statement. “Thanks to our partners at the FRA, the alternative schedule is a major milestone that will ensure we can continue building on the progress we’ve made.”

For more information on the project, visit mbta.com/ptc.