A fatal crash in Auckland early on Tuesday has brought the region's road toll to 55 - the same number as for the whole of last year.
Police say it appears the rising use of cellphones by drivers is partly to blame.
The Waitemata Serious Crash Unit routinely obtains cellphone records when investigating fatal smashes.
Sergeant Stu Kearns, who is in charge of the unit, says it is not possible to determine how many crashes are caused by cellphone use. He says most drivers in accidents will not admit to using their phone, while minor accidents will not be routinely investigated.
Mr Kearns says talking or texting on phones means drivers are distracted from what is happening on the road, more so than from talking to a passenger in the same vehicle.
He says although hand-held sets are safer than holding a phone to your ear, people are still engrossed in the conversation and therefore not fully concentrated on their driving.
