For most of the summer, I come home from work, eat dinner, wait an hour or two, and then run around 7:30 or 8:00 when its cooler. Then we get to September when it's dark at 7:30 or 8:00, so I come home, head out for my run, and then eat a late dinner afterwards. Once sunset creeps up to the 6:00 or 6:30 hour, I'll start my run from the office right after work, instead of driving home first.
Eventually, in the middle of winter, it will become impossible to even leave work before dark at all (fully dark in the 4:00 hour is the worst season, in my opinion). Have to deal with either the boredom of the treadmill or risk of running outside.
Running outside in the dark makes me incredibly nervous, though. In my experience drivers don't pay attention to pedestrians even in broad daylight (seriously, why won't drivers look to their right before turning right?!). I won't step foot in front of a car until I've made eye contact with the driver - but you can't make eye contact if you can't see through the windshield because it's dark.
At the moment, I have a pretty good compromise. I live in a large apartment complex, and the parking lot is a loop almost a half mile around. I put on a reflective vest, and run laps around it. There is some light from street lamps and carport lights - not enough to be fully seen without reflective gear, but enough to notice potholes or other obstructions in my path. I'm assuming that within a parking lot, drivers are (1) going to be going slower than while pulling out of a parking lot onto a road, and (2) expecting and watching out for some pedestrian traffic of people walking to and from their cars. This scenario also leaves me constantly next to residential buildings, so hopefully there would witnesses if anything troublesome occurred.
If you google "how to run safely in the dark" you'll find lots of articles with a few common pieces of advice, basically falling into two categories: avoid being hit by cars and avoid being attacked.
Be safe from cars: Stay on routes with sidewalks or wide shoulders. Become familiar with routes during the day so you're aware of potholes, etc. Wear light colors, reflective gear, and flashing lights.
This is sort of a mixed bag - my normal routes are on sidewalks in residential areas. The problem is that those residential areas have lots of driveways and apartment parking lots that result in cars crossing the sidewalk.
I'm trying to become more visible, buying more bright, neon clothing. I'm also looking into more reflective gear besides just the vest - Relax Reflect has some cool looking pants and arm warmers. I actually own a headlamp, which includes a flashing red light on the back, but I haven't gotten around to using it yet.
Be safe from people: Stay in well-lit and busy areas. Carry a cell phone and ID. Don't listen to music. Run with a friend. Let someone know where you're planning on running and how long you'll be. Vary your routes.
My residential neighborhoods are kind of busy, during the 6 - 8 pm mid-evening hour with people coming home, but I would be a little nervous about often going stretches without actually seeing anyone. There are some street lamps, but not a ton. I also tend to stick to the same loops, because I have an awful sense of direction - made even worse in the dark!
Regardless of the additional safeguards I could take, I'm definitely hesitant to venture outside my parking lot to run after dark.
Perhaps I should run the opposite direction I usually do, into a commercial area? If I cross the freeway and continue on my street, it's actually a pretty major road connecting two suburbs. I normally avoid it because it's so heavily trafficked (car fumes + too many people watching me), but for nighttime running that could be pretty good. More witnesses in case of trouble, more street lamps, and more traffic lights on cross streets.
Do you feel comfortable running in the dark? What precautions do you take?