it may work in a quiet town like omaha in nebraska. not in sf with all kinds of traffic types like pedestrians, bikes, scooters, pmds, buses, trams, taxis, ubers, lyfts, jaywalkers, joggers, alcoholics, bums, homeless, drug addicts, and worst of all, chink grannies who think roads belong to their great grandfathers. moreover, the city is hilly, has difficult turns, and cable car tracks that may get tires stuck in the grooves.