I agree with Tzvia. Although I don't commute through "unsavory" areas, I do ride at 5-6:30 AM, mostly in places with no streetlights. And I drive in a lot of bad areas for my job, and I have thought about how I would ride there. Sometimes I think it's overkill, but generally, I have my very bright front light and 2 blinkies in the back, as well as a blinking ankle band. I also wear a Nathan reflective vest when the ride is in total darkness, like at this time of the year. Sometimes I put another blinkie on my back, clipped to my vest or jacket. Last week I rode to the gym and I have to cross a highway at about 5 AM; my bike does not trigger the signal and there are rarely any other cars going my way. There is a walk signal at both the curb and again the median; when it was light or even semi light, I could ride across the highway to the median, as there's rarely any traffic going that way, and then I press the button to get across the second half. Well, it was pitch dark and I realized I needed to really press the signal for the first half, as I felt uncomfortable. But, the pole/signal was on the sidewalk and I already had my bike sort of parallel to the highway, by the cross walk. Because I was so lit up, a car, far away, actually stopped to let me get across, although he didn't have to. I *know* he saw me.
I won't put reflective tape on my road bikes, for the obvious reasons, but I have worn my hiking headlight (not a huge one) on my helmet. It really doesn't help me see, but I think it lets others see me. There isn't a lot of traffic or hardly any cars when I first go out, but by the time I return, there is a steady stream of people heading to work. And delivery trucks unloading at the stores/restaurants in the town center. Once in awhile I feel like I'd like some side visibility, but I haven't found a solution that's not permanent or a lot of money. At one point I had a blinkie on the side and now I'm wondering why I took it off.