Comment by SoftTalker

I agree, but if the streets are set up accordingly, it's about as fast as you'd normally want to drive anyway.

For the standard US road with 12-foot-wide lanes and generally straight-ahead routes, 20mph does feel very slow. I've driven on some roads though where narrower lanes, winding paths, and other "traffic calming" features contribute to a sense that 20mph is a reasonable speed.