Half the city basically only has one lane of traffic because of all the g-d damn construction and the Red Zone Bus/Taxi lanes for which 30% of the people take.
http://m.sfgate.com/bayarea/article/San-Francisco-traffic-Uber-Lyft-SFMTA-blame-10791265.php
http://m.sfgate.com/bayarea/article/San-Francisco-traffic-Uber-Lyft-SFMTA-blame-10791265.php