Running in the dark is relatively safe if you take some precautions. Run in good well lit neighbourhoods. Wear high viz clothing to make sure you can be seen by motorists. Use a headtorch to make sure you don't put a foot in any potholes. Tell someone where you're going. Take a cell phone and ditch the headphones. Stick to a route you know well. Try and run on traffic free routes. Carry ID just in case. If possible run with a friend.