I'm slow and average about 7 mph (about 11kph) going to work and well under 5 (8kph) going home. I'm more about getting there than speed. That and the hills.

The main thing with a commute is that i do not want to get there all sweaty. Since my commute is along a river, wind direction plays a large role here. But generally it varies from 15 to 20 mph. I intentionally go slower when it is warm for obvious reasons and tend to put in more effort when going back (dont care about how I look or smell when I get back, usually take a shower anyway).

Well......that explains it.

I'm new (in my 3rd month of bike ownership). My commute is 16 km each way. My *goal* is 32 km/h. So far my fastest has been 29.7 km/h. My average is 25-28km/h. Today the wind was 30, gusting to 40 km/h in my face - only managed 22km/h! Ugh. (Hope it stays that way for the ride in tomorrow morning - then dies. lol)