SMOKING POT WHILE DRIVING DEFENDED

Small amounts of marijuana have virtually no effect on a person's ability
to drive safely, an expert on behaviourial psychology testified at the
trial of a Calgary man Friday.

The trial of Calgarian Patrick Houlgrave, 23, wrapped up Friday with
testimony from an expert on marijuana's effect on the way the brain functions.

Houlgrave faces charges of impaired driving causing death in a crash on
Dec. 27, 1997, on the Trans-Canada Highway between Banff and Lake Louise.

Defence lawyer Rick Muenz's case hinges on what effects the marijuana had
in contributing to the crash that killed Doug Harrison, 36, a father of
three. Court heard earlier in the week from Houlgrave's former girlfriend
Melinda McFarlane who said the pair shared a joint before driving on the
Trans-Canada Highway.

"Small amounts of marijuana have no discernible effect on driving either in
simulators or in dual-control vehicles," said Dr. Barry Beyerstein, of
Simon Fraser University, quoting conclusions from recent academic research.
"As you increase the marijuana, you see effects on some attitudes and
reaction time."

Crown prosecutor Shirley Jackson earlier presented her own expert that
stated marijuana use does in fact impair judgment and affect driving ability.

Muenz countered that the Crown failed to prove, beyond a shadow of a doubt,
that the crash was the result of nothing more than treacherous winter
driving conditions.

Houlgrave's westbound truck hit an oncoming minivan killing Harrison, the
driver.

Court of Queen's Bench Justice Peter McIntyre said he will give his
decision Tuesday.