I can ramp it up pretty well when I want to, but most days the commute is just that, making the wheels turn, listening to a good book, or just the birds singing, and enjoying what's around me. I leave so that even if I'm turtling along at 10mph, I will still make it to work 15 min early, and if I have a flat, then I have to make up a little time, and that makes it fun too. I usually save the speed tests for the ride home, my best average on a ride home was 19.5 last year, I've been dreaming of a 20mph average ride home, but the red lights and stop signs seem to be at odds with said plan (The averages are moving averages, but every slowdown and then speedup kills that average on an ~8 mile ride).

Joe