20" of snow, that would make it tough to ride in alright. the sand paper roller would probably do well in wet weather though.
I Remembered something while thinking of your friction drive. I had a little friction drive a few years ago that I really liked, called a MX-5. It is no longer available but the drive roller is what I want to tell you about. The roller had several groves cut across the width of the roller and they were not that deep. What I think is good about this is, just about anyone could make the groves with a metal cutting saw or even a 3 cornered file. This roller was made of steel and seemed to last forever.
With your idea and these two types of rollers: Most do it yourself people could put this together with simple tools and very little cost. Rain or shine a person could have simple, inexspensive and reliable transportation.
What do you think?