You have to regard the additional hazards of bicycling in San Francisco or Portland - the close proximity of the homeless tents to the street traffic, strong likelihood of getting your bicycle “carjacked” by some homeless person, and the simple road hazard of riding through mounds of feces or pools of urine on the potholed streets. Not to mention getting a flat tire from all the hypodermic needles lying about.
Once you are on that bicycle, head for the nearest open road to the next town or the town after that, where cycling is vastly much safer.
The tubeless tires have really gone a long way in reducing flats.
Maybe SF and Portland are Dyke Friendly?
In SF, the hills making biking difficult for many.
At least here in Michigan on Mackinac Island you can ride through what normally comes out the backside of a horse and simulate what the Amish have to do on a daily basis minus dodging needles and the threat of being bikejacked