San Francisco packs a lot of driving into a small, hilly peninsula. US 101 enters from the south as a freeway, then becomes the Central Freeway and runs along Van Ness Avenue and Lombard Street to the Golden Gate Bridge. I-80 crosses the Bay Bridge from Oakland and joins the 101 near SoMa, while I-280 runs along the city's southern and eastern edges toward the Peninsula. SR 1 follows 19th Avenue and Park Presidio Boulevard through the west side, connecting Daly City with the Golden Gate Bridge.
Traffic and terrain shape every drive. The approaches to the Bay Bridge back up much of the day, Van Ness and 19th Avenue are slow and signal-heavy, and the downtown grid is crowded with buses, delivery trucks and pedestrians. Streets climb steep grades in Nob Hill, Russian Hill, Pacific Heights, Twin Peaks and Bernal Heights. A car that stalls on a hill or in a bridge backup is a hard place to be, and getting it repaired where it's parked is far easier than towing it across the city.
SFO sits south of the city in San Mateo County, and its long-term garages and lots are a common spot for a no-start. Muni buses, light rail and cable cars cover the city, BART connects to the East Bay and the airport, and Caltrain runs south from Fourth and King. Many households here own only one car, and with street parking scarce and garages tight, a shop drop-off can cost a parking space and a full day.