The DMV has lots of painted curbs, some ledges, and a whole lot of smooth, flat pavement (a rare thing in SF). This isn't really worth a special trip for, but if you live nearby or are passing through, it's a decent warm-up spot. Old timers will remember the BofA rail and the whale curb across the street (which are no longer there).

Come on the weekend or after hours, when they are closed.