The introduction of random breath-testing of drivers has been a long time coming. But while the move suggests drink-driving is at last being treated with the seriousness it deserves, medical experts warn of an equally serious danger on our roads - drug-driving.
In 2005, more than 14,000 people were tested for drink-driving, a figure which is almost certain to be surpassed this year as a result of random testing. In contrast, just over 750 people were tested for drug-driving, according to the Medical Bureau of Road Safety at UCD, where blood and urine samples are analysed.
Discussions between the bureau and the Garda are taking place about the implementation of a training programme called Field Impairment Testing (FIT).
"It's basic training in roadside tests to help gardaí recognise when people are under the influence of drugs," says Prof Denis Cusack, director of the bureau. "While 750 drug tests last year is low, there were just 78 tests in 2000, so it's been increasing steadily over the past few years."
One of the problems faced by police forces worldwide in their attempts to combat drug-driving is the lack of suitable equipment.
Prof Cusack says an EU meeting in Strasbourg was recently told that nine roadside drug-driving instruments tested had been found to be incapable of detecting the majority of drugs.
"While an effective instrument to detect drug-driving by the roadside doesn't exist, it's still important for gardaí to learn the signs so that they can arrest someone on a suspicion and then carry out an effective drug test at the station," he says.
Dr Bill Tormey, consultant chemical pathologist at Dublin's Beaumont Hospital, says gardaí must urgently address the problem. "Cocaine is particularly dangerous because.. . it can lead to aggression and speed on the road."
Dr John Latham, a GP who works with drug users, agrees. "Cocaine . . . alters people's judgment and combined with alcohol, it's very unpredictable."
The doctors stress that it's not just illegal drugs that can be dangerous; people taking prescription drugs should not drink when driving and should ensure their prescription clearly states whether it's safe to drive.
In terms of how much alcohol will push someone over the limit at a roadside random test, medical experts say it's not a black and white issue. What can push one person over the limit may not affect the next person, as it depends on an individual's size, sex, food intake and alcohol tolerance. But the resounding message from the experts is not to risk even one drink because the legal limit is not necessarily the safe limit. "Research has indicated that 50 milligrams of alcohol makes you unsafe to drive, but the legal limit is 80 milligrams," Prof Cusack says.
In 2004, more than 12,000 breath, urine and blood samples were tested for alcohol. "Only 8½ per cent of these tested positive for between 80 milligrams and 100 milligrams. But now with random testing we expect to see a huge rise in detection at these levels," he adds.
Gardaí have warned that they will also target drivers who may be drink-driving the morning after the night before. "I expect they'll catch many people with random morning checks," Dr Latham says.
There is no definitive way to judge whether you're legally and safely capable of driving the morning after a night out. Medical opinion is divided on how long you should wait before attempting to drive a car.
"Sufficient sleep and food will help but there's nothing special you can do except maybe not drive if you don't feel up to it. Habitual drinkers might only need five hours before driving while others may need double," says Dr Tormey.
Dr Latham says that if you're going to be driving the next morning, it's important to stop drinking at a reasonable hour.
"If you're drinking heavily until 3am, you shouldn't even consider it. Even if you've only been drinking moderately, you should give yourself eight hours just to be safe," he says. "And it shouldn't be about fear of getting caught, it should be about safety."