I do see some people on the bike path going faster than I can imagine going. They have no cargo, or they have a small backpack and no rack/luggage on the bike. I imagine some are commuting but most are just riding. When you commute to work, you generally have stuff to carry.

I rode at the same speed as a couple of bike commuters Wednesday evening, and we were going at around 17 mph, much faster than I usually go.