Whether or not riding on the sidewalk is illegal in your area is not the point. Whether or not drivers know that is not the point. The point is that motor vehicle drivers are not looking for cyclists at crosswalks and driveways. Yeah, plenty of people have been hit by cars in those places because they're not expected to be there. So that answers your question.

This is the road cycling forum. Perhaps this thread should be moved to commuting, or hell, A&S. The latter would have a field day with this one.