NJ Transit will slash its service for the next three months so that it can finish federally mandated safety work by the end of the year — and it will offer a small discount to riders for the inconvenience, officials announced on Thursday morning.

The agency has to cut service so it can finish installing positive train control, a life-saving technology that all railroads in the United States are required to have in place by the end of the year, said NJ Transit executive director Kevin Corbett.

“Our customers will always be our first priority, and their experience must be safe and consistent,” Corbett said in a release. “We thoughtfully reviewed all trains that are part of this adjustment and found the most reasonable alternatives.”

The Northeast Corridor, North Jersey Coast Line, Morris & Essex Lines, Montclair-Boonton, and Main and Bergen County Lines will feel the biggest changes. There will also be minor adjustments on some other lines, said agency officials.

PTC is a GPS-based system that uses onboard electronics and transmissions from track-side signals and radio towers to automatically apply brakes if speeding trains are in danger of derailing or crashing.

NJ Transit plans to offer its riders a 10 percent discount on all rail tickets and passes while the changes are in place, officials said.

The changes will start on Oct. 14. The agency will go back to its regular schedules in the middle of January, said Corbett.