Most car owners would tell police about drink drivers, leaving offenders facing stratospheric car-insurance premiums following a conviction, research shows.
An AA survey found that nearly half of motorists know someone who drinks and drives and most would report them to the authorities.
Drinking and driving seemed most prevalent in the West Midlands, according to the poll of more than 11,000 motorists. Scottish road users were the most law-abiding when it came to legal alcohol limits.
The poll coincides with a safe winter-journey campaign run by Central Scotland police, drinks manufacturer Diageo and Central FM.
The research showed that 47% of motorists knew someone who drank and drove, and that 67% would "shop" such people to the police if they had consumed enough alcohol to put them far in excess of the legal limit.
AA president Edmund King said: "More than 400 people were killed in drink-drive crashes last year in Britain so drivers are best advised not to drink if they are going to drive.
"Drink-drivers need to look over their shoulder and stay away from the car as almost half of those that know them are likely to report them to the police."
© Press Association 2008