Donovan Lagrange, 33, was struck while walking back to his patrol car from two other vehicles he had pulled over in a speed trap.
The accident happened at around 2:20 p.m. ET on Highway 640 East, near Bois-des-Filion, about 30 minutes northwest of Montreal.
The nine-year veteran of the provincial police force was rushed to hospital in critical condition, and his death was reported early Saturday evening.
An investigation is underway.
Police say too many motorists are unaware of a law requiring them to give a one-lane berth to emergency vehicles stopped on the side of the road.
The "move-over" law went into effect on August 5, compelling drivers to slow down and move away from service vehicles parked on the side of the road that have their lights on. This includes emergency vehicles, tow trucks attending to other vehicles and surveillance vehicles equipped with flashing yellow arrows.
According to the Canadian Automobile Association website, over the past three years, the SQ recorded 214 accidents involving vehicles stopped on the road. Four people were killed and three were injured.
Drivers who fail to abide by the law can face fines from $200 to $300 and receive a penalty of four demerit points.
Other Canadian jurisdictions already have their own "move over" laws. The Quebec government followed suit, drafting its legislation after a municipal police officer in Bromont, Que. was hit and killed in Dec. 2011.
La Sûreté du Québec is looking for witnesses to the accident in which Lagrange was struck. Anyone with information is asked to call 1-800-659-4264.