The majority of drivers killed in crashes involving only one vehicle are young men twice to three times over the legal alcohol limit, a new analysis of coroner's court files has shown.
Lecturers from forensic and legal medicine at UCD carried out the study into the causes of single vehicle crashes by examining every fatal crash in one county - Kildare - over an 11-year period.
Of 184 people killed in crashes in the county between December 1994 and December 2005, 79 were in single vehicle crashes. When toxicology data for the 40 drivers in these crashes were examined, researchers found that 24 had alcohol in their system, 12 did not and four drivers were not tested.
The report, Single Vehicle Collisions in Co Kildare, found that among the drivers killed, those who drink "tend to be far in excess of the legal limit."
"This report conclusively proves what everyone has long suspected: young men are being killed in single vehicle crashes. However, we were surprised by the level of alcohol. They are not just a little over the limit, but twice and three times," said Dr Cliona McGovern, one of the authors. Out of 67 deaths, speed was mentioned as a definite factor in 21 deaths, or roughly one third. Nine out of 10 of the drivers killed were male, with men under 30 years of age accounting for 45 per cent of driver fatalities. Overall, 86 per cent of those killed in single vehicle crashes in Co Kildare were men.
While the authors, Dr Cliona McGovern and Prof Denis Cusack, could not study whether driver fatigue was a factor, between 8pm and 4am was found to be when the highest number of fatal crashes happened, accounting for 43 per cent of deaths. The largest number of fatal crashes occurred at the weekend. According to the authors, this suggests that fatigue is a contributory factor.
Also examined was the type of road on which the fatal crashes occurred. Co Kildare has a mixture of dual-carriageway, national and regional roads and this latter category accounts for the vast majority of fatal crashes.
Only eight of the 79 crashes happened on dual-carriageways, whereas 38 deaths occurred on regional or third-class roads. The level of deaths on smaller or rural roads were far higher than researchers expected.
They were also surprised that drugs were not found to be a significant issue in the fatal crashes in Co Kildare. Out of the 40 drivers killed during the period of the study there were only two positive tests for drugs.
This is at variance with a recent report on drug driving in Ireland that showed 16 per cent of all drivers tested positive for drugs. The authors of the Co Kildare research said incomplete toxicology records and the smaller sample size may explain the difference in results.
No evidence was found of single vehicle crashes being disguised suicides, with only one case having a suggestion of this.
A recent US study had found that up to 14 per cent of fatal single vehicle crashes may be a result of suicide but the evidence from the Co Kildare coroner's court found no conclusive evidence of suicide.
However, this does not mean that some single vehicle fatal crashes are not suicides, says Dr McGovern, just that there was no proof. The report contains warnings for pedestrians too.
They identified a number of cases where intoxicated pedestrians were hit and killed by a vehicle. In two cases the deceased was hit while already lying on the road. In five cases the person was killed after stumbling into the road at night.