San Francisco City and County law
a) Prohibits skateboarding on any city street at any time, on any sidewalk in any business district at any time, and on any non-business district sidewalk commencing 30 minutes after sunset and ending 30 minutes before sunrise (Traffic Code, Section 100)
b) Prohibits skateboarding "in or about any public transit station (including an outdoor high-level boarding platform), streetcar, cable car, motor coach, trolley coach or other public transit vehicle, including, but not limited to, those stations or vehicles operated by the Bay Area Rapid Transit District" (Traffic Code, Section 128)
c) Prohibits skateboarding in Yerba Buena Gardens, the Japanese Tea Garden, the Arboretum, Conservatory Valley, where it is posted as prohibited, and in South Beach Park or Rincon Park unless otherwise permitted (Park Code Sections 3.05 and 11.02 and Port Code Sections 2.4 and 7.2).
d) Requires skateboarders at skating facilities owned or operated by the City and County to wear helmets, kneepads, and elbow pads (Park Code Section 4.17).