I find that when I ride my bike home at night with a flash red light attached to my backpack, cars will come a little bit closer to me in my bike lane. On the rare nights that I forget to pack a light, it seems that they work harder to give me some breathing room. I have an untested and baseless theory for why this happens. It's not that subconsciously drivers want to run cyclists down, but because the flashing light draws their attention. It's a bit like skiing through trees. If you look at the trees instead of the open spaces between them, eventually you'll hit a tree. With their eyes drawn to my flashing light, the driver's natural tendency to begin coming towards me. I believe this is true, but not so much that I'd start riding without a light.