The legal alcohol limit could be lowered following a government review.
Transport Secretary Lord Adonis has commissioned independent research into the effects lowering the limit could have. The report will be finsihed by April, and a drop in the drink-drive limit and tougher curbs on drug driving could follow.
The current limit is 80 milligrams of alcohol per 100 millilitres of blood, but the government is reported to be considering lowering the limit to 50 milligrams.
Lord Adonis said: "Road safety has improved significantly in recent years - 1000 fewer people now die on the roads in a year than in the mid-1990s - and Britain now has one of the safest road systems in the world. "But we need to cut further the number of tragedies on our roads. Drink-driving killed 430 people last year, and research suggests drug-driving is a key concern for the public."