"Anyone who hasn't landed on their head previously might not realise the significance of it until they're in a crash."
Police have issued more than 85,000 tickets nationally to cyclists not wearing helmets in the past 10 years.
Fourteen cyclists have died on NZ roads and 332 have suffered serious injuries since January last year, NZ Transport Agency (NZTA) figures show. Two of the dead cyclists were not wearing helmets.
Non-compliance can result in a $55 infringement fee or maximum $1000 fine on summary conviction.
Cycling Advocates Network (CAN) spokesman Patrick Morgan said the helmet law discouraged people from cycling and the organisation wanted the law reviewed.
Mr Morgan obtained an exemption to the helmet legislation under medical grounds when he provided a doctor's certificate in 2004.
He only wears a helmet when he deems there is sufficient risk.
"It's kind of like if you imagine a car racing driver. They'd probably wear a helmet because they're doing a high-risk thing, but when you drive down to KFC you probably wouldn't bother."
A New Zealand medical journal article published in February this year found New Zealand's bicycle helmet law had failed in aspects of promoting cycling, safety, health, accident compensation, environmental issues and civil liberties.
The article estimated the law cost 53 lives each year in premature deaths due to a corresponding reluctance to cycle and lack of exercise.
NZTA spokesman Andy Knackstedt said exemptions could be given on religious or medical grounds. Nearly 150 exemptions have been granted since the law was introduced - four this year.
Bicycle helmets were made mandatory in January 1994.
The origins of the helmet law were widely attributed to the campaigning of Rebecca Oaten, dubbed the "helmet lady", in the late 1980s. Ms Oaten campaigned for helmets to be made compulsory after her son Aaron suffered permanent brain damage when hit by a car while riding to school in Palmerston North in 1986. APNZ
