Average on my flat 5 mile commute is about 14 according to Garmin. I consider it to be higher than that because of the time I spend slowing down, and accelerating away from traffic signals. I did that commute once at a Garmin average of just a hair under 19 (max 28) mph-catching most of the lights, and having a favorable tailwind. All time fastest was about 50 down a long, straight grade with no cross streets. Won't do it again because those brakes did not smell good after stopping for the signal at the bottom.