Pubdate: Fri, 15 May 2009
Source: Comox Valley Record (CN BC)
Copyright: 2009 Comox Valley Record
Contact:  http://www.comoxvalleyrecord.com/
Details: http://www.mapinc.org/media/784
Author: Tim Schewe
Note: Tim Schewe is a retired RCMP constable with many years of 
traffic law enforcement experience. His column appears Friday.

DETECTING MARIJUANA IMPAIRMENT

Q: I recently overheard a conversation between young people where 
they discussed the daily use of marijuana - on their way to and from 
school and in their cars. They said it did not affect their ability 
to drive and that it went undetected by parents, teachers, employers 
and the police.

Could you please discuss what methods are available, if they are 
being utilized to identify drivers under the influence of marijuana 
and how effective they are?.

A: I did not receive Drug Recognition Expert (DRE) training during my 
traffic enforcement service, but I was able to work alongside others 
who had been trained, and learned enough to be confident of my 
decisions when I issued 24-hour prohibitions for the use of marijuana.

A driver under the influence of marijuana is more difficult to detect 
than most other illegal drugs, but the drug does produce the 
following symptoms: bloodshot eyes, accelerated heart rate 
(tachycardia), muscle tremors and forgetfulness. Marijuana 
impairments include: difficulties with judgment, depth perception and 
the ability to maintain attention. All of these skills are necessary 
for the safe operation of a motor vehicle.

How effective are drug recognition experts? A driver may be convicted 
of driving while impaired by a drug based on driving or care and 
control evidence and the impairment evidence given at trial by the 
DRE. Recent amendments to the Criminal Code have significantly 
expanded the use of the DRE by making it a requirement for a 
suspected impaired driver to submit to an exam rather than 
voluntarily participate.
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MAP posted-by: Jay Bergstrom