A Roads in the countryside in the dark with no streetlights and a 60mph limit, which slightly pissed locals drive at 70. You can't see the edge and people drive like maniacs.
Lanes, fine. North Africa, fine. US freeways, fine. London, no problem. A Roads in Cornwall, no thanks.
My only exception in London is Streatham which I also hate, never in the correct lane for the turn and all the markings are on the bloody road which you can't see in nose to tail traffic.