"Already the number of people being killed by drug-impaired drivers on New Zealand roads is higher than those killed by drivers above the legal alcohol limit. There have been years and years of media campaigns to stop people drinking and driving, but still they do it. So what is planned to educate people on taking drugs and driving?"
Leggett said a car or motorcycle that hit a truck would "come off second best," creating significant stress for truck drivers, even if they were not at fault.
"It's a basic law of physics, with big heavy trucks and lightweight cars and bikes. But any injury accidents, no matter who is at fault, are very stressful for truck drivers," he said.
"Higher risk on the roads also likely means higher insurance premiums across the board. Insurance is risk-priced, and you pay on probability. When households and businesses are already managing tight finances, they shouldn't be surprised by expenses that should be made clear up front."
He urged everyone working in the road transport industry to "drill down" to the unintended consequences of making cannabis legal before voting.