After many years of driving cab on the day shift, I have switched over to driving cab at night. It is really just an experiment whose verdict is not out yet. All I can say so far is that it is a different way to be tired than the day shift.
I thought traffic would be easier to deal with at night, but what I found out is that traffic is also bad at night at least up until around 7pm.
San Francisco has some serious traffic issues. I would say that traffic in the last year has gotten worse than I have ever seen it. My un-empirical opinion is the congestion is worse from the addition of new residents to the city, un coordinated construction work, and increase in unregulated car services.