Just found this statistic on Mesa, AZ cycling accidents:

Mesa Bicycle Accidents - 1996
..........................Against Traffic....With Traffic
Street..........................106................116
Sidewalk.......................94..................15
Crosswalk.....................41...................22
Totals..........................241................153

Of course this is numbers, not percentage of those who ride in either mode. But my observations are that folks in Mesa (and other Phx-metro suburbs) ride at about a ratio of 50 sidewalk to every 1 street rider, so it is curious to me why so many more accidents are on the street.

Al