In the second of a five-part series, CTV Edmonton’s Bill Fortier learned law enforcement considers itself ready for legal marijuana—but some of the public has questions.

Police have adopted a simple message for marijuana users.

“If you’re going to use cannabis, just be safe and responsible about it,” said Cst. Braydon Lawrence of the EPS impaired driving unit.

“And find a good ride home,” he added.

But those who choose to drive high will face consequences.

If a driver is found to have more than two nanograms of THC per milliliter of blood, they could face a ticket up to $1,000 and as many as 18 months behind bars.

If a driver’s blood level exceeds five nanograms of THC per milliliter, they would face a mandatory $1,000 fine and could receive up to five years in prison.

The penalties increase when a high driver injures or kills another person.

Police will be relying on two methods of roadside enforcement: standardized field sobriety tests and the Draeger 5000.

The former requires the person being tested to do a number of tasks while officers asses their physical and cognitive ability, like tracking an object with their eyes, or balancing on one foot.

The second method—the Draeger 5000—is a device the federal government chose to use in August. It analyzes saliva samples to detect the presence of drugs.

But its approval in the summer left little time to bring in equipment and train officers, causing some to wonder how effectively Canadian police will be able to use them.

One local criminal defence lawyer, Ed O’Neill, believes the ability of the Draeger 5000 will be questioned in court.

“There's going to be a challenge respecting the veracity of the device,” said O’Neill. “What the courts are going to be looking for is whether or not this Draeger device is, in fact, reliable.”

The test has been criticized for its accuracy, invasiveness and cold-weather performance.

“It's operational between four and 40 degrees Celsius. And that raises the question: boy, on a cold, frigid, wintery night in Fort McMurray or Yellowknife or even in Edmonton, is this device going to be reliable?” asked O’Neill.

However, Lawrence said police will first conduct field sobriety tests in an impaired driving investigation, and that about 600 members will be trained to conduct the tests within a few years.

Not only is the impaired driving unit ready to deal with high drivers now, Lawrence said they have been for years.

“We are going to be in a really great position come legalization date.”

With files from Bill Fortier