I'm riding a Worksman Industrial Bike (ie, a Slow Bike). On the White Rock Creek/ Lake trail, my best average speed so far is 15.7 mph. I would say that's not far off, maybe better than the average rider out there (not to be confused with the average serious rider!). But there are occasional people that pass me like I'm sitting still (ie, probably doing 25 mph or better). That's about a 1-1/2 hour ride, varying depending on route. And it is reasonably flat, and I am pushing myself, maybe not hard, though.