WASHINGTON (WDVM) — Metro will be going forward with returning the 7000-series railcars to service after getting the okay from the Washington Metrorail Safety Commission (WMSC).

Metro had previously submitted a plan to WMSC after pulling most of their cars when a wheel assembly issue led to a train derailment. They plan to gradually bring half of the 7000-series back to service, aiming to add 42 cars to the rails. Metro said that this will help provide “more frequent, reliable service.”

“This is part of the process that will enable Metro to announce a more definitive service plan after the first of the year. Until that time, the transition of the 7000-series railcars through the end of the year will allow us to improve reliability,” GM/CEO Paul J. Wiedefeld said in a release.

The 748 cars that had been pulled make up around 60% of Metro’s railcars. This has reduced Metro service since October, with this affected service stretching through Dec. 31.

Metro will be monitoring the returned cars for 90 days.