Bliviot
An oblivious idiot. A person who continues to do the stupid or ignorant thing he is doing while ignoring all the people around him who are trying to tell him he's doing it. Usually associated with American vehicle operators, both motorized and human-powered.
This dude drove down Mission from the airport with his lights off and nobody could get his attention. Somebody finally got out of their car at Reservoir St and knocked on his window to tell the bliviot to turn his lights on.