Traffic, especially cross-traffic, doesn't see you. When a car pulls out from a business, the driver scans THE ROAD and NOT the sidewalk for vehicular traffic. Even if the driver checks for pedestrians, cyclists are speedier and could be out of sight one moment and on a car hood the next. Similarly, if a car wants to pull into a business, generally drivers are NOT checking the sidewalk for fast moving traffic.
What if the road you are on is just really, really terrible? What if you've chosen the best route possible and you just have to ride along this crummy street and riding in the road spells s-c-a-r-y a-s s-h-i-t. And to top it off, you're an experienced commuter that understands the risks of riding on the sidewalk and will take special precautions to prevent these particular dangers.
Then, YES-- in my PERSONAL opinion.. I think that it would be appropriate to ride on the sidewalk. I have done so in this very situation I've described. However, I don't come across this situation very often. I am usually very good at route selection and I am not shy about "taking my lane," as it is my legal right to do so. I'll write more about "taking the lane" in the future-- in short, it's when you ride in the MIDDLE of the traffic lane instead of the right third. This forces traffic to have to change lanes and go AROUND you instead of trying to squeeze you off the road.
Interestingly enough, one of our "bike paths" here in Walla Walla is along Dalles Military Road. It's basically an extra-wide sidewalk that bikes are supposedly expected to use. I didn't know that it was such a "shared use path" until it was pointed out to me by a City engineer during a Bicycle/Pedestrian Committee meeting. My response was, "you want me to ride on THAT? How am I supposed to make a left turn??" Not to mention-- it trains cyclists to think that it's okay to ride on the sidewalk all the time. And it tells cars that bikes don't belong on the road. In reality, Dalles Military Road actually has a HUGE shoulder and there is PLENTY of room for two lanes AND a bike lane.. and maybe even a parking lane too (if they hadn't put in the glorified sidewalk).
Now, if this "shared use path" actually looked and was marked as a shared use path-- like the Copenhagen-style cycle path that is now being installed in Portland..
Graphic designed by the folks over at BikeHacks, one of my favorite blogs!
Well, you see-- a cycle track is separate from pedestrians, protected from traffic by parked cars and marked heavily so that cars know to expect bicycles there. The Dalles Military sidewalk is none of these things.
The real solution to this whole problem, would be for our towns and cities to spend an appropriate amount of money on bicycle infrastructure (instead of straightening out curvy roads that are TOTALLY FINE.. *ahem). But until then-- we do our best with what we've got..
and complain about it 'til it changes. :)