Fatigue is believed to be a factor in one in five driver deaths in Ireland.
According to Gardaí international research points to tiredness being a contributory factor in around 20% of road deaths in which the driver is killed.
They are reminding motorists this Bank Holiday to take care on the roads and to pull over and take a break if they are feeling tired.
Five people lost their lives on the country's roads over the June Bank Holiday weekend and Gardaí have said motorists need to take more care.
"If people are tired they should stop the vehicle and get out and walk or get a cup of coffee," said chief superintendent Michael O'Sullivan from the Garda National Traffic Bureau.
"If they're tired they shouldn't take on a long journey
"Basically there is international research suggesting that fatigue could be a contributing factor in one in five driver deaths in Ireland."