Funny, because I ran this Saturday out of sheer boredom, and ran 14 km (according to http://www.gmap-pedometer.com/) in ~ 1:21. If you subtract traffic lights and the short times I looked at maps, I probably ran it in 1:10. (I live in the city). Either way, it's not a great time. I used to run very very often, but 5 min/km isn't so bad when I really think about my situation. I haven't done any real running in 15 months. I was just going out there because it was sunny, and I was bored. 
