I was very encouraged to see [MENTION=45088]nlerner[/MENTION]'s data, because I know he's a much more fit rider than I am but I think if I made a max effort I could match those average speeds for at least the first 10 miles.

At the peak of my fitness (which was when I was around 45 because I spent most of my life as a couch potato), I could average 17 mph on my very flat 10 mile commute. As Neal observed, stopping and starting drags that down a bit, especially for a commute. At that time, I probably could have averaged 20 mph on mostly flat open roads (I've never been able to climb at anything more than a snail's pace). About the time I hit 50 my performance took an absolute nose dive. I thought it had to be health related, so I went to see my doctor. His professional opinion was that I'm getting old. I guess we all hit the curve differently, but I really didn't expect the lights to go out so quickly at this age. A few cardio tests confirmed the doc's diagnosis though. Every indication is that my heart and lungs are healthy. I'm just getting slow.

To paraphrase Oscar Wilde, the only thing worse than getting old is not getting old.