DRUG-TESTING PLAN FLAWED, NORML SAYS

Group fears bias, inaccurate results

Whangarei: A pro-cannabis lobby group is concerned a proposed trial to test
drivers for drug use could be too subjective to be accurate.

Police booze bus staff nationwide will be trained this month to identify
drivers on drugs, in preparation for a three to six-month drug-testing
trial, expected before June. Northland is one of the likely testing spots.

Staff will learn to spot a driver on drugs by physical indicators and tests,
such as requiring the driver to stand on one leg. Police would then require
the motorist to take an evidential blood test.

While the regions for the trial have yet to be decided, police national road
safety manager Superintendent Steve Fitzgerald said earlier this year that
Northland was a likely option.

National Organisation for Reform of Marijuana Laws (Norml) spokesman Chris
Fowlie said Norml did not support people driving while impaired in any way,
but was concerned with how police would determine what constituted
"impaired".

"All the government is preparing is a subjective test where an officer will
decide on the spot whether someone is affected by drugs, based on dilated
pupils, slurred speech and their ability to walk a straight line.

"Our big concern is that there will be potentially biased officers taking a
very subjective assessment of a driver."

He said that while blood-alcohol readings could be very accurate follow-ups
to breath-testing in the case of alcohol impairment, the high-inducing agent
in cannabis, tetrahydrocannabinol, broke down into non-psychoactive
metabolites [which do not cause impairment] very quickly.

These could be stored in the body for up to a month.

"It [the test] is useless for measuring impairment. Clearly people would not
be impaired a month after smoking a joint," Mr Fowlie said.

In contrast, harder drugs such as methamphetamine, or P, were harder to
detect, both subjectively and in blood tests.

"The methodology's ill-conceived and will see a lot of people of no danger
to road users potentially being arrested," he said.

Overseas studies showed cannabis could have an effect on reaction times and
people's ability to maintain a steady straight line in their lane, he said.

However, people concentrated more on their driving when stoned than when
they were sober and were much less likely to take risks when driving, Mr
Fowlie said.

Mr Fitzgerald has said the "field impairment tests" were designed by
neurologists and properly trained staff would be 95% accurate in determining
whether drivers were on drugs.

Under the Land Transport Act, it is an offence to drive under the influence
of drugs to the extent of being "incapable of having proper control of the
vehicle".

Currently, there are no defined thresholds for the level of drugs that would
render a driver "incapable".