[OldManAndTheCpp]

I don't understand why you went back to using a scooter, if you were so clearly able to diagnose the dangers, and had one fairly severe injury. Why not switch to a commuter bike (the ~1 ft wheel foldable ones)?

Also, separate question, my understanding is that potholes are mainly formed by freeze/thaw cycles -- weather not typically found in SF. Have you lived in Chicago or NYC? Can you contrast the pothole density between those three cities?

[brianpgordon]

After the first time, I thought it was a one-off and that I could avoid further injury by being more careful. After the second time, I realized that was foolhardy.

Potholes in asphalt can be caused by pressure from tires too. I've never tried biking or scootering in a different city so I can't compare the quantity of potholes.