What a sad little thread. No because of the question but because of the obvious blood spitting anger that occurs when someone suggests we might limit top speeds.
It should be part of the test, ask someone the question, if they get angry they're not ready to drive a vehicle. Give 'em a bike and let them experience speeding idiots for a while, then ask them the question again.
As for the original question. It's unworkable at a voluntary level and would make more problems than it solves. It'd need to be mandatory, across the board, which would be impossible.