The Sûreté du Québec will be especially visible on the province's roads over Labour Day weekend.

Impatience plus cellphones and speed are a cocktail for a collision, said Sgt. Ronald McInnis of the SQ.

He said long weekends are especially busy, often causing people to either drive aggressively or not pay attention to the road.

So far this weekend, there have already been two collisions.

Two motorcyclists are in critical condition following separate accidents on Quebec roads.

 A 47-year-old woman is in critical condition after her motorcycle collided with a van in the town of Dolbeau-Mistassini, in the Saguenay-Lac-St-Jean region.

The 55-year-old behind the wheel of the van was also hurt.

The second motorcyclist was injured on Friday afternoon after her motorcycle collided with another vehicle while making a turn. 

The incident happened in Brome Lake, in the Eastern Townships. The motorcyclist was struck while turning onto Highway 104 from Highway 139. 

The driver of the vehicle that hit her was treated for shock.

Traffic Jacques-Cartier Bridge Montreal

The traffic lights on the bridges indicate lane configurations. (CBC)