118 people have died on Irish roads so far this year.
Research carried out by the RSA shows that 7 in 10 crashes happened between 10pm and 6am.
The counties with the highest number of people killed in crashes during off peak hours, were Dublin, Donegal and Louth.
Gardaí say they're concerned about the increase in the number of fatalities on the roads, and are appealing for motorists to be vigilant.
Most of them are happening in rural areas with speeding, not wearing seatbelts and the use of mobile phones some of the main causes.
Road deaths have been falling over the last few years but there are now concerns that progress could be at risk.
80 per cent of deaths have come on rural roads - most of them in Dublin, Cork and Tipperary.
And there's been a reduction in cyclists, pedestrians and passengers involved in fatal crashes.
We're being warned Sunday is the most dangerous time to be on the roads.
The time most collisions take place is between midday and 10pm.
Gardai say hundreds of extra roads policing officers are needed to help keep the number of road deaths down.