The Road Safety Authority (RSA) is issuing its October Bank Holiday road safety appeal.
It has also revealed that 75% of deaths between the hours of 10.00pm and 6.00am had a positive toxicology for alcohol.
While the age profile of drivers and passengers killed during off-peak hours is considerably younger than those killed during peak hours.
Some 37% of drivers killed during off-peak hours were aged under 25, and almost half were aged 25-44.
While 61% of passengers killed during off-peak hours were aged 18-24.
The RSA analysis looked at off-peak fatal collisions over a five-year period, to highlight when and where these collisions are happening.
Seven in ten fatal collisions occurring during off-peak hours, not involving pedestrians, were single vehicle collisions - meaning no other car was involved.
Men are over-represented in off-peak deaths making up 87% of drivers, 73% of passengers and 87% of pedestrians killed on Irish roads between 10.00pm and 6.00am.
Transport Minister Shane Ross said: "Driving during off-peak hours presents its own risks.
"However, the same advice applies regardless of when you are on the road - you need to slow down, belt up, don't use the phone while driving, never drink and drive, or drive while fighting sleep behind the wheel.
"I would urge all drivers to consider their behaviour not just this Bank Holiday weekend but every time they use the road whether that is midday or midnight."
Moyagh Murdock, CEO of the Road Safety Authority, added: "Despite traffic volumes being at their lowest, 27% of fatal collisions and 17% of serious injury collisions occurred during off peak hours.
"Road traffic collisions that happen late at night and into the early hours differ in key ways to those that happen during the day in two respects: young males are over-represented and 75% of fatalities had a positive toxicology for alcohol.
"Continued education and enforcement are needed to target those most vulnerable groups namely young male drivers, young male passengers and male pedestrians."
A total of 46 people have been killed or seriously injured in October Bank Holiday collisions between 2012 and 2017.
To date this year, a total of 118 people have died on the roads - which is four more than up to the same period last year.
