Here is a story as a point of interest:
My co-worker started to bike to work (2 miles). She hadn't ridden a bike for a long time. She rode on sidewalks because the streets are very busy. She was crossing a street with the walk, and another car did a right turn on red without seeing her and hit her knocking her over. ambulance took her to the hospital Fortunately it wasnt that bad and she only had an injured ankle. she was very lucky. She was wearing a helmet and she said she was glad she was. At the scene , one cop said that it was illegal to walk on the sidewlk and was about to give my friend a ticket!! - the other corrected him and said it was ok.