Helmet lights are really good at preventing drivers from pulling out or turning in front of you. I've got a Fenix LED flashlight mounted on my helmet, and it really helps visibility in traffic. When I see a car ahead in a sidestreet or parking lot, I just turn my head toward them briefly and they get a quick shot of 100+ lumens, which gets their attention. Haven't had anyone pull out in front of me since I put the light on my helmet.

Also, you say you wear visible clothes, but how visible? Screaming yellow, neon yellow-green is the most visible color -- far better than red, orange and other options. I usually wear neon yellow jerseys, vests or jackets when it's dark as well as some ankle bands in the same color.