I can generally do that or pretty close to it on the way in to work during spring and summer. That is with a fresh set of legs, little traffic, and really going at it. On the way home I rarely can get around 20+ mph due to fatigue and traffic. Especially with commuting, where things are different every day, I think its hard for most to get a consistent workout every day they ride.

My take away from commuting is at the end of the day, I should be having fun doing it.