Muni’s 21-Hayes bus line returned to service on July 9, 2022 after a 27-month pandemic suspension. Early in the pandemic, Muni management hoped that the crisis might give them an opportunity to rationalize the network by permanently shutting down some of the parallel routes that dated back to the 19th century. The 21 was one of several lines, including the 2-Clement and 6-Parnassus, on that list.
