I have a short 5.5 mile, flat, with very little traffic, and no red light commute. On a good day, on my road bike, I can average 17 driveway to driveway. My record is 18.1 but even averaging 17 hurts my legs as I don't get to warm up and I seem to need that. My top speed on level ground is 30 but I can't hold it any longer than to see it on my Garmin.