The group most likely to have driven after consuming alcohol were young men under the age of 24 living outside Dublin. The numbers in that group admitting drinking and driving has quadrupled since 2014.
However, the behaviour was found among men and women of all ages and in all geographic settings, countering the notion that it is primarily an issue in rural areas where there is a lack of alternative transport.
John O’Mahony, director of research firm Behaviour and Attitudes, which carried out the survey for the Road Safety Authority (RSA), said the finding was significant.
“We found one in 10 drove after consuming some level of alcohol in the past 12 months,” he said. “10% might seem like a reasonably modest percentage but in population terms it equates to 270,000 motorists.”
Moyagh Murdock, chief executive of the RSA, said the findings were “alarming”, particularly the trend among younger drivers.
“While we all welcome an uplift in the economy, more of our younger generation are in jobs, more of them are back into cars and there’s more disposable income in their pockets and unfortunately it’s manifesting itself in more propensity to drink and drive,” she said.
The survey did not ask how much alcohol, on average, motorists drank before driving but the standard legal limit equates to less than a pint of beer while for learner and novice drivers it is less than half that again.
Yet one in four motorists (24%) felt it was OK to consume alcohol before driving, even if they did not do it themselves. One in ten said it was safe to drive after one drink, 4% said two drinks was fine, 3% said they would be safe to drive after three or more drinks, and 7% said less than one full drink was OK.
In total, 73% said zero alcohol was the only safe limit but that plummeted to 23% among the one in 10 drivers who admitted drink-driving over the past year.
The same group were also less likely to agree that drink driving seriously increased the risk of an accident or made it difficult to react appropriately to dangers on the road.
“It’s very strongly indicative that it is almost habitual for this group to have some level of alcohol before driving or to be comfortable with driving after having some level of alcohol,” said Mr O’Mahony.
One positive finding from the survey was the effect of the Crashed Lives campaign run by the RSA featuring the story of four-year-old Ciaran Treacy, killed by a drunk driver in 2014.
Three-quarters of all motorists who saw the campaign said they were prompted to take extra precautions against drink driving while planning a social outing but that increased to 81% among the group who admitted they had personally driven after drinking.
Ms Murdock said she was also heartened by the finding that 91% of motorists supported or strongly supported an automatic driving ban for anyone caught over the drink-driving limit.
The RSA is backing proposed legislation to end the practice whereby motorists caught at the lower end of the limit are fined and given penalty points but not banned.
The survey also looked at general driver behaviour, finding 59% of motorists were consistently careful, safe drivers while 32.5% were occasionally careless or rule-breakers and 9% showed consistently poor behaviour.
The key danger group were identified as males under the age of 34 from higher social classes living in Dublin. The most common risk factor was their use of hand-held mobile phones while driving.
On average each month this year, 740 motorists were caught drink-driving, 13,000 speeding, and 1,000 with no seat belt.
Chief Supt Aidan Reid said the figures were “staggering” and warned that extra checkpoints would be in place over the always busy bank holiday weekend. He also said all gardaí had been reminded that they had the power to breath-test anyone stopped for any minor traffic infringement and should do so at “every opportunity”.