+1 When I started commuting in spring '08, I waited till I had daylight for both directions (my workbound commute starts at 6:30am and homeward ends at 6:30pm). When it started getting dark earlier in the fall, I got better lighting and clear safety glasses and kept commuting. Winter came and I got a jacket, warmer gloves, headband to cover my ears and track pants and kept commuting.

Commuting in the dark isn't at all what I expected it to be and now I can't imagine letting a little darkness spoil my rides. And my commute involves everything from 6 lane road traveling at 50 MPH plus to commercial areas with no street lighting to a stretch through the middle of downtown that's lit up like daytime.