I very nearly nodded off on the M1 into London one morning a couple of years ago, I'd set off from Manchester at about 5AM. Since then I insist on heading down the afternoon before and staying over night. I don't think I actually fell asleep, I could just feel my head go, which was quite scary.

That stuff about the lorry drivers was quite scary. I remember nearly being run off the road in thick fog by a lorry driver who didn't like the speed I was doing. It's all very well for them they're unlikely to kill themselves. The lorry in question had one of those 'How's my driving?' stickers on the back so when I got to safety I ran it and complained. Never heard a thing back.