The SFO run is longer than the map suggests
Distance is not what governs this trip. Everything north of SFO funnels through one bridge, and the approach to it runs through San Francisco itself, so the same drive that takes an hour at ten in the morning can take ninety minutes at half past four. Our chauffeurs run the corridor daily and know which of the two ways across town is moving on a given afternoon. Southbound matters too: the Golden Gate is tolled in one direction only — inbound toward the city — so your departure transfer to SFO carries a bridge toll your arrival did not, and both are already inside the rate you were quoted.