Cannabis 'improves' driving, some users say

Two thirds of cannabis users say the drug does not affect their driving ability, while 16 percent say it improves it, according to a new survey.

Almost 1200 people responded to an online Drug Foundation survey ahead of the introduction of new drug-driving tests set to be enforced by police from December.

Almost 80 percent of those who had driven while under the influence of cannabis felt their driving was not changed or was better.

New Zealanders' were assessed on their knowledge, attitudes and behaviours around driving under the influence of psychoactive substances, including illicit drugs, prescription medicines and alcohol, for both users and non-users and drug drivers and non-drug drivers.

Out of the 1164 people surveyed, 1124 were drivers, 36.4 percent were cannabis users and 7.7 percent were methamphetamine users.

Nearly a quarter, 23.6 percent, of drinkers surveyed reported driving under the influence in the past year.

Driving under the influence of multiple substances was the most dangerous driving behaviour in terms of impairment, yet 11.6 percent of respondents reported doing so in the past year.

More than two thirds (70.5 percent) "totally agreed" or "somewhat agreed" that random roadside drug testing would improve road safety in New Zealand.

A long-term study was being carried out by Environmental Science and Research to analyse blood samples from most driver deaths in New Zealand.

Preliminary results showed 40 percent of drivers killed between 2004 and 2006 had used alcohol, cannabis or both before their death.

Thirty percent of drivers who used cannabis and died in a motor vehicle accident were likely to have smoked within three hours of driving.

But the number of people convicted of drug-driving was low, as there was no technology to detect drug users quickly .

Provisional police data showed 69 people were charged with driving under the influence of a drug last year, compared with 60 in 2006 and 84 in 2007.

Only one person was charged with causing death while under the influence of a drug.