You can't underestimate the value of a good reflective vest. I live in Florida, and we get ridiculous fog on the coast. On those mornings, I wear a reflective vest which has flashing LEDs, plus I have two Planet Bike Superflash blinkies facing the rear(one on the bike, one on the helmet). The DiNotte headlight up front covers forward lighting. I'm not afraid in the fog. Getting wet is more of a concern. It sucks to break out the rain jacket in warm spring fog.