Same in DC. Legal everywhere but downtown. In fact, on one of the busiest streets, Mass Ave., the sidewalk is a designated bike path. I think this is just the city being lazy, because there are multiple street crossings, many without lights or stop signs, and turning cars always seemed surprised when they see me. Sometimes I ride on the street, but it is 4 lanes with no shoulder and some cars go 50 mph. The sidewalk seems safer, but not by much.