A Lismore magistrate is stepping down in large part because he can no longer face applying NSW’s strict drug-driving laws.

David Heilpern told ABC News there is no clear proof cannabis adversely affects driving and described the current laws as “grossly unfair”.

Under the rules, drivers caught with drugs in their system lose their licence for at least three months for a first offence and six for subsequent offences.

David Heilpern - Cannabis Legalisation Australia - Cannabiz
Magistrate David Heilpern said NSW’s drug-driving laws are “grossly unfair”.

Helipern said: “The vast majority of people brought before the courts on this charge are not affected [by the drug]. It’s a historical or relatively benign impact on their driving ability days, or even weeks, after use. I just thought the laws were so grossly unfair that I didn’t feel I could continue to apply them.”

The 58-year-old could serve on the bench until he reaches 75 but has decided to step down to focus on not-for-profit legal work, environmental activism and drug law reform.

He added: “When they introduced random breath testing, the road toll decreased massively. When they introduced seatbelt laws, there was a reduction in the road toll. I have seen nothing to show any reduction in the road toll as a result of the thousands and thousands of people who are appearing before courts for historic use of cannabis.”

The NSW transport department said 74 drivers involved in fatal crashes last year were found to have an illegal drug in their system (THC, speed, ice, ecstasy or cocaine).

Transport for NSW Deputy Secretary Tara McCarthy insisted driving after taking illegal drugs is extremely dangerous. She added: “Any member of the community who has used illegal drugs is advised to be conservative when making the decision to resume driving. [Mobile drug testing] is designed to deter drivers who have recently used illicit drugs from taking the risk of driving.”

Heilpern said while he supports changes to cannabis legislation, his job as a magistrate was to apply the law, not to make it.

“We take an oath to uphold the laws of New South Wales and I took that oath seriously.” he added.