I want fairly accurate distance so I can know calories burnt. Calorie counting ended up being more realistic if I tossed time spent doing what activity out the window and instead focused on miles, since cycling 20 minutes at 12 miles an hour were the same calories as walking 1 hour at 3 miles an hour.

Speed is important to me since I've been non active for a month and wearing layers now makes me feel slower. I want to make sure I'm not unreasonably slow when part of traffic.