One in five New Zealand drivers admits falling asleep behind the wheel and the number is on the rise.
The statistics were revealed in a recent AA Insurance Drivers Index survey of more than 3500 people.
The Automobile Association is asking drivers to beware of fatigue and respond appropriately to prevent a crash.
AA Insurance says driver fatigue-related claims are increasing and cost the industry $4.8 million a year.
Operations head Martin Fox says the study also showed a 14% increase in the number of people who said they would not stop to rest if they were tired.
Men were less likely to admit they were tired and could have an accident resulting from fatigue. The biggest number this type of claim came from men aged 18 to 29.
Mr Fox says taking a break from driving and resting is the best way to stay safe when travelling on a long journey.