I ran 3.1 miles on the treadmill. I did intervals slightly, they were .25 to .50 mile intervals but still I also mixed up the inclines.

I'd much rather be outside but there are times it's dark and cold and the weather doesn't accomodate my wishes. For those who go to the treadmill in the winter, how do you simulate outside running for training purposes? I know the treadmill is easier, right? So if I run 5 miles on the treadmill, it wouldn't carry over to 5 miles outside. How can I offset that?