Reduced Metro service will continue through at least Nov. 15 as Metro officials work to get 7000-series trains back on track.

The Washington Metropolitan Area Transit Authority announced Thursday that trains will continue to operate every 15 to 20 minutes on the Red Line and every 30 to 40 minutes on all other lines while WMATA develops a plan to safely return the 7000-series railcars, about 60 percent of the fleet, from their removal from service after a derailment earlier this month, according to a release. WMATA is developing plans with the Washington Metrorail Safety Commission to test the 7000-series trains and return them to service, but the agency offered no firm timeline for when that would be completed.

“We’ve completed inspections of every 7000-series railcar, over 3,000 axles in all, and are now working with the WMSC on a testing plan that will allow the trains to safely return to service,” Metro General Manager Paul Wiedefeld said in the release. “We will continue to provide regular updates to our customers and the public as more is known about a timeline for full service restoration.”

WMATA is also working to increase the number of older trains in operation to improve service times as the investigation continues.