A quarter of the car drivers killed in 226 crashes in 2006 were not wearing a seatbelt, according to a report published last night.
In a detailed study into deaths and injuries on Irish roads that year, the Road Safety Authority (RSA) also found that almost three-quarters of car drivers killed in crashes were male.
The Road Collision Facts 2006 also reveals the impact of mandatory alcohol testing (Mat) following its introduction in July 2006.
The RSA says the introduction of Mat was the most likely reason there were just 17 fatalities in August that year, the lowest for any month in 2006.
The impact of drink-driving enforcement can be seen in the fall in fatalities and serious injuries in crashes in 2006 compared with the previous year.
The number of people killed in 2006 fell to 365, down from 396 the previous year, with the six months after the introduction of Mat accounting for almost the entire decline.
The number of people seriously injured was 907, with a further 8,575 road users lightly injured in collisions.
Noel Brett, chief executive of the RSA, highlighted the decline in the number of fatalities per million vehicles over the 10 years to 2006.
In 1996 the fatality rate per million registered vehicles was 338; 10 years later this had fallen to 159 per million vehicles.
"By examining how we are doing, based on the number of vehicles on the road, we get the clearest indication of whether our roads are getting safer," said Brett. "And what this shows is that each individual road user is twice as safe now compared to 10 years ago."
Interestingly, despite the fall in deaths, there was an increase of around 700 to 28,417 in the overall number of collisions reported to gardaí in 2006, an indication perhaps of an ever-more congested road network. In 22,399 collisions no one was injured.
The RSA estimates the cost of road deaths and injuries to the economy in 2006 at €1.33 billion.
The most dangerous time to be on the State's roads in that year was 6pm, a fact that the RSA attributes to fatigue, as it is the time when the highest number of motorists are leaving work.
Between 9pm and 3am - the hours most associated with drinking and driving - 99 people were killed in crashes, or 27 per cent of all fatalities.Saturdays, Sundays and Mondays were the worst days of the week for crashes, accounting for 207 deaths, or 57 per cent of all deaths. According to the report, Wednesdays are the safest day on the roads. January had the highest death toll from crashes in 2006, with 40 people killed.
The number of single-vehicle crashes increased marginally in 2006 and accounted for 31 per cent of all fatal crashes.
According to the RSA, this type of crash is most commonly associated with a loss of vehicle control due to speed, driver fatigue or drink driving.
While the report notes some successes over the 10-year period to 2006, that year also marked the end of the State's second road safety strategy in which a key target - to reduce road deaths below 300 - was missed.
The 2004 to 2006 strategy also called for over 460,000 drivers to be breath tested, a target that the State has yet to achieve - based on the stated Garda Traffic Corps position that they are carrying out around 30,000 breath tests per month.
It also called for more than 11 million speed checks to be carried out. However, the procurement process for the privatisation of a speed camera network is delayed causing the chairman of the RSA Gay Byrne to criticise the departments involved.
The Road Collision Facts 2006 report also notes that the number of car user fatalities increased between 1996 and 2000 before decreasing sharply until 2003, which coincided with the introduction of penalty points. For the following three years, deaths among car users increased gradually.
The number of pedestrians killed on the roads fell between 1997 and 2003, but since then have increased and 73 - mainly elderly pedestrians - were killed on the roads in 2006, accounting for 22 per cent of all deaths.
Some 43 per cent of pedestrians killed were aged over 65 years of age, and seven out of 10 in this age group were killed in crashes at night.
Motorcycle fatalities fell sharply in 2006, almost halving to 29 deaths, and accounting for 8 per cent of overall road deaths that year. No reason is given for this fall. Nine cyclists were killed on the roads in 2006, with a further 211 injured in collisions, and accounting for 2 per cent of all fatalities.
Driver error was the most significant contributory factor for collisions in 2006 and was identified as the cause in 88 per cent of Garda collision reports. The next most common cause of collisions were pedestrian errors, at 7 per cent, with road factors accounting for 2.5 per cent.
