A new law has come into force in France forcing drivers to carry two breathalyser kits in their cars, in a move aimed at cutting the number of alcohol related deaths on the road.
Those without the kits risk an on-the-spot fine and all motorists must also have with them a high-visibility safety vest and a warning triangle.
Foreign drivers are included in the new rule, however there is a grace period until November.
Some 4000 people are killed on French roads every year, with drink-driving being the main factor in accidents ahead even of speeding.
The French government hopes that with breathalysers in every car, drivers who suspect they may be over the limit can test themselves and if necessary refrain from taking the wheel.
The former government of President Nicolas Sarkozy, which gave the go-ahead to the new law, said it hoped 500 lives might be saved every year.
A BBC correspondent reports that tens of millions of the kits are going to have to be supplied, but right now there is a shortage, which is one reason for the four-month grace period.