AS the legalization of marijuana approaches, there are still unanswered questions, including the effectiveness of roadside drug testing and what prices will be. 

It was originally slated to come into force on Canada Day, but after much wrangling, Oct. 17, 2018, will go down in history as the day the recreational weed prohibition died in this country. With the passage of Bill C-45, it will be legal to buy and consume it.

Ending the 95 years of prohibition is a sweeping change that comes with knowns and unknowns. What we know for sure is this: Under the legislation, known as the Cannabis Act, adults will be allowed to carry and share up to 30 grams of marijuana in public. They’ll also be allowed to grow four pot plants in their homes. In this province, the Nova Scotia Liquor Corporation will have a monopoly on the sale of pot and the legal consumption age will be 19 — the same as liquor. Anyone else trying to sell weed will face steep fines.

Municipalities will control where pot may be smoked, with bans and restrictions on consuming it in public places such as parks, on sidewalks and near playgrounds. They’ll also decide if pot can be grown outside and impose fines on those who break bylaws. (Buying, selling or consuming pot will be illegal till Oct. 17; all penalties apply till then.)

As for driving under the influence of marijuana, that has always been illegal, but under Bill C-46 — sister legislation to the recreational cannabis law — police will have new powers to conduct roadside checks on drivers and to use saliva tests for drugs and alcohol. The Impaired Driving Act sets thresholds for THC levels in the blood, and those exceeding such levels will be subject to fines and criminal charges comparable to penalties for driving under the influence of alcohol.

What is not known is how reliable roadside drug-screening devices will be and it is expected that there will be court challenges on the devices and accuracy of THC screening. This will clog up court time.

Also undetermined is the price of pot. The NSLC will have to find a price low enough to keep legalized weed out of the black market while generating tax revenues to pay for sales, distribution and enforcement. Statistics Canada concluded that Canadians pay an average of $6.83 per gram. It is assumed that consumers will pay a little more for regulated, safe weed sold by government.

Another unknown is whether Canadians previously convicted of using marijuana will be pardoned under a pot amnesty. No commitments have been made thus far.

A bigger unknown is how Canadians will be treated at the U.S. border. Even though pot is legal in a number of U.S. states, it is illegal under the U.S. Controlled Substances Act, and that is the law at the border.

Canadian officials have advised travellers to be honest if a U.S. border official asks if they’ve ever used marijuana. If the answer is yes, U.S. officials will be within their rights to deny entry, and even ban a Canadian for life.

The workaround is to tell the border guard that you are not obligated to answer the question. The U.S. official will still have the right to deny entry, but the Canadian can always try again.

In legalizing pot, Canada might be trading one set of problems for another. The question is whether the new liabilities will become just as big a headache — for the general public and the Trudeau government.