Forty-one million Americans [1] consider themselves runners. We are by far outnumbered by the 202 million licensed drivers in our country. In light of those numbers you need to play it safe and run defensively. Here are a few ways to run safely as the days become shorter:

• No matter how much reflective detailing decorates your sneakers, and no matter how bright your neon windbreaker seems, you should never assume drivers can see you. Pay attention to the traffic around you.
• Make yourself as conspicuous as possible. Wear a flashing red bike light on your back.
• Make eye contact before you cross the street or in front of a car.
• Run against the traffic, whether you run in the street or on the sidewalk. If you run in the street, since asphalt is kinder to knee joints, be aware of cars making right turns, since motorist often don't look around when turning right.
• Keep your iPod volume down, and if it is dark skip music entirely so you can use your ears to stay aware of approaching cars.
• Most importantly, if you're running in the dark, run with a buddy. Two people are more visible than one, and you can look out for each other.

Source [2]