Winnipeg police say they nabbed a man driving while high on meth during a routine checkstop on Main Street Wednesday night.

Police were doing an annual holiday season checkstop near Market Avenue when they came across a driver at about 9:30 p.m. who did not have a driver's licence or contract for the rental car he was driving.

"The driver exhibited signs of impairment by drug," said Const. Tammy Skrabek, and police spotted a syringe beside the driver.

The man, 42, confessed that he had injected meth earlier. He was arrested and police found more meth on him.

The man gave officers a false name, and it was also discovered that the rental car he was driving had been stolen from Scarborough, Ont. They identified him after fingerprinting him, Skrabek said.

How to identify

The procedure to determine whether someone is impaired by drug use starts the same way as with alcohol, said Const. Stephane Fontaine of the police traffic division.

"There's all kinds of indicators or signs of impairment [officers] observe," he said. 

"If it's not alcohol, it could be a drug. We have specially trained officers that recognize the difference between alcohol and drugs, and specifically the signs and symptoms that are specific to different drug categories."

People under suspicion are placed under arrest and tested, Fontaine said. 

"A drug recognization evaluation is a 12-step process in which we look at several different signs of impairment, whether they're clinical-based or psychophysical."

An evaluator determines whether the person was under the influence of drugs and what kind, he said.

It can become complicated when people use both alcohol and drugs, or more than one type of drug, Fontaine said.

"[But] if we can detect the impairment, it really doesn't matter to us so much as what's causing the impairment."

The man, who has no fixed address, faces charges of drug possession, impaired driving, public mischief and possession of property obtained by crime.