"This means if you are tired, make the right decision to pull over safely and take a break.
"Concentrating on the road does take a lot of effort. Don't underestimate the impact this has on your ability to concentrate and to react in an emergency. By taking a break, you can come back onto the road refreshed and give the road your full concentration, which it needs."
Mr Greally said drivers also need to remember that not all roads are created equal.
"Many of New Zealand's roads are unforgiving and leave no room for mistakes," he said.
"Check your speed, and know that the speed limit is the maximum speed you can travel at safely in ideal conditions.
"The decisions you make as the driver could be the difference between a great summer and one marred with the pain and devastation a fatal crash causes."