Now this is cool.
Flowing data has gathered a number of activity logs and
mapped out the most popular routes of major metropolitan areas. These maps are from
RunKeeper, so the routes from your humble
Strava-using bloggers are't included, but it's still interesting to see. His conclusion:
If there's one quick (and expected) takeaway, it's that people like to run by the water and in parks, probably to get away from cars and the scenery. In the smaller inland cities, there seem to be a few high-traffic roads with less running elsewhere.
Of particular interest for us is
the Boston and
the Washington DC maps.