This is a good article that speaks of some designated cycling fascilities. I am lucky to have a very long stretch of the road that does not have any intesections. Maybe that what helps me. I can go at least for 10 miles or more at a time without stopping unless I chose to do that. And I have a several hills on the way that are about 1-2 miles long. So, maybe we should start talking about average speed per certain distance.