I seem to recall a Freakonomics chapter or podcast episode that discussed drunk driving vs. walking home drunk, and concluded that walking home drunk was even more dangerous than driving home drunk. Either choice is much worse than ride-sharing or cabbing or public transit, obviously.
It's safer to drive only for the driver, as the driver usually survives car accidents and is less likely to drunkenly wander into traffic or get mugged, for example. For others, it's much more dangerous if a drunk person drives (such a person will hit pedestrians, other cars, etc).
