I ride a little over 6 miles to work. It generally takes me 30 minutes and I try to maintain a cruising speed of 15 when I can. Cyclometers can be deceiving about average speeds. My best average according to the cyclometer was 13.9 mph. On that particular day I rode up to red lights and stop signs and stopped abruptly. On another day I coasted slowly into intersections timing lights so I didn't have to stop. My average speed was about 12 mph. On both days it took me the same amount of elapsed time to get to work.