The San Francisco Municipal Transportation Agency (CA) is considering expanding all-door boarding to its bus fleet. Muni riders with Clipper cards or proof of payment already have the option to board light-rail vehicles through the back door. Now the agency is considering extending the policy to buses to speed up operations on crowded routes. The agency has not yet made a decision and still needs to consider factors like timing, routes, and enforcement. Link to full story in San Francisco Chronicle.