San Francisco Buses (but Not Trains)

The San Francisco Municipal Transportation Agency announced via a series of tweets on Monday that it would continue to require masks on Muni metro rail, rapid buses, cable cars, streetcars, and shuttles.
However, the Bay Area Rapid Transit network of trains, or BART, will no longer be enforcing its masking policy, according to a report by the San Francisco Chronicle. The transit agency has not yet announced a formal mask policy update, but the Chronicle reported that BART police officers have been instructed by their superiors to stop telling people to put masks or face coverings on.