Choose a well-lit route
It might not be your favorite route to run, but the most well-lit route is your safest choice. Oncoming cars see you better, and you'll always be able to see the road and avoid potential hazards.
Always run against traffic
It's easier to avoid cars if you can see them coming. Avoid busy roads and those with no shoulders or sidewalks.
Run with a Buddy
There's strength and safety in numbers. If possible, try to never run alone. If you're running alone, let someone know the route you're running and approximately how long you will be out.
Carry a cell phone
You'll be able to contact police immediately if something happens to you or you notice anything out of the ordinary.
Vary your routes and times
Potential attackers can study runners' routines and loom in a particularly dark or isolated area. Don't make yourself an easy target.