I have been riding off and on for a 6 years. Nothing serious. I started out more recently by attaching a kiddie trailer for hauling my son around. It was great excercise, especially climbing the small hilled roads.
When I go alone, usually for about 17 miles after work, I average 17 mph. I can usually pedal @ 18-21mph on the flat ground without too much effort. I would like to get an idea of what is an average speed so I know how much I need to improve. Any tips on how to increase speed would be great.