A new device to curb drinking and driving is being introduced in Florida.
Breath tests have long been a weapon against drink driving
Motorists with a history of drinking and driving will have breathalysers fitted to their cars - and the vehicle will start only if they pass the test.
From Sunday, installing the device - called an Interlock - is mandatory for all those with at least two prior drink-driving convictions.
The authorities say the move is designed to reduce road deaths - but critics argue it is too stringent.
Florida lawyer Steve Casanova says the Interlock is set to block ignition at the merest trace of alcohol.
"Rinsing your mouth out with a beer will be sufficient to trigger this device," he told the BBC's World Today radio programme.
He says the Interlock can also require the driver to take the test at any time during a trip, and will shut the ignition if alcohol is detected.
Mr Casanova added that only law-abiding people - rather than serious offenders - would be affected.
"I think the whole programme is basically a joke, because the people who really want to drive drunk and have lost their licences will do that anyway," he said.
"People drive without licences all the time."
However supporters of the device say it will stop some of the carnage on Florida's roads.
"A drunk driver without a car is a drunk pedestrian," Florida State Representative David Simmons told the Tallahassee Democrat newspaper.
"If we can significantly reduce these deaths and injuries, we will have gone a long way," he said.
Those required to use the locks will pay for them.
The cost is $70 for installation and about $67 a month for monitoring.