Headlights, or not!

Having done an inordinate amount of miles in the last couple of weeks in this bad weather I have one major gripe.
It's snowing, or foggy, or dark, or all of these. You get the picture, poor visibility. So PUT ON THE F~~***#G HEADLIGHTS! people. Young and old, cars, vans and trucks, all guilty. What with dirty windows and mirrors how can you be expected to see some twat overtaking you without his/her lights on. It costs nothing but could save an awful lot of grief.
There, rant over.