Hours of Muni delays were caused by problems at the train control system Thursday.
The system has been at the center of attention, with the Board of Supervisors recently approving a $30 million agreement to improve the setup.
The system controls the location, speed and routing of trains, and the braking of light-rail vehicles in the Muni Metro subway system between the Embarcadero and the West Portal. It is considered the “backbone” of the transit system, accounting for more than 120,000 daily trips.
On Thursday, problems with the control system caused delays with outbound trains, which eventually pushed inbound trains behind schedule, Muni spokesman Judson True said.
The problem was resolved after a few hours.