Remember the key to cycling safety when it comes to those around you - VISIBILITY. As a driver, I can guarantee you that I see cyclists better on streets than I do on sidewalks. Maybe it is because I believe that is where they belong. SideWALKS are no place for fast-moving vehicles. In fact, I caught a jerk coasting the sidewalk in my neighbourhood on a Frankenstein and told him if I am ever pulling out of my drive while he is on the sidewalk, I will not yield to him.
I am quite outwardly spoken when it comes to safety. I will even slow down to tell people on scooters to put helmets on, like the couple I saw on one with their helmets dangling off the sides.