Why We’re Keeping Commercial Trucks Out of Some Left Lanes on the Coquihalla

No trucks sign Coquihalla

We’re restricting commercial vehicles from using the far left lane northbound on the Coquihalla’s Snowshed Hill between Box Canyon and Zopkios with our No Trucks in the Left Lane pilot program. The restriction is in effect year-round.

November 23. 2020 Update: We’ve added the left lane travel restriction for commercial vehicles to the uphill sections of Larson Hill and Inks Lake Hill , to this pilot program. Regulatory signage, the same as at Snowshed Hill, has been installed to mark the beginning and end of the areas. Snowshed, Larson and Inks Lake hills all have three lanes going in one direction.

The Coquihalla Highway is one of the province’s busiest mountain passes. Both passenger and commercial vehicles rely on it as a primary connection between the Lower Mainland and the Interior. It also experiences extreme snowfall rates, with accumulation sometimes exceeding 10 cm per hour. That’s a LOT of white stuff coming down. Even with regular plowing and sanding; snow and slush accumulates on the road surface quickly, reducing traction and visibility. Add a spun out commercial vehicle (or more) to the mix and things can get messy really quickly.

Commercial vehicles blocking traffic during snow storm on Snowshed Hill

On Phase 1, between Hope and Merritt, the snow is heavy and wet, creating tricky road conditions for trucks, even with minor accumulations on the road surface. Over the past couple of winter seasons, commercial vehicles on the Coquihalla have been spinning out in climbing sections more frequently during storms. In fact, last winter, 33 of 35 extended closures on the Coquihalla during last winter involved commercial vehicles. At times, this meant commercial vehicles were blocking the highway until they could either be towed away, or equipped with chains (which they should have already had on their vehicles). What makes these closures even worse is that, because the Coquihalla is a divided highway, snow plows often get caught in the traffic queue behind the blockage, restricted by roadside barriers and unable to turn around. So, snow continues to fall, unplowed, until the blockage is cleared. Not good.

Commercial vehicle gets traction help from tow truck on Coquihalla

We hope to prevent a repeat of that trend by restricting commercial vehicles from using the far left lane.  We chose to pilot this restriction first on Snowshed Hill, because our Commercial Vehicle Safety Enforcement focuses a large part of their enforcement efforts on this location during the winter months and this is where trucks spin out the most. By restricting trucks from the left most lane, we will be better able to maintain traffic flow (including emergency vehicles) and plowing operations, as well as significantly reduce the time it takes to re-establish the flow of traffic after a vehicle incident/closure. “Keep right, let others pass” rules are still in effect – we are taking this action to ensure no trucks use the left most lane.

Maintenance contractors clear highway ahead of commercial traffic


We’ve also recently constructed and opened the Box Canyon Chain-up area (located on the Coquihalla, before Snowshed Hill). We’re expecting commercial vehicles to use this facility when snow falls on the Coquihalla, in advance of heading over the summit. The facility can hold up to 70 commercial vehicles at a time and can also accommodate oversized loads as well.

If we have the Coquihalla Snowshed Protocol activated, and the two lanes get blocked by spun-out trucks, we will hold trucks at the Box Canyon Chain-up area until these lanes are clear. If trucks come upon spun out trucks in the right and centre lanes, they need to stop, just like they would have to if all three lanes were blocked.

The safety and mobility of the travelling public are our top priorities. We hope that this change will help both of these over the coming winter on the Coquihalla. If you have any questions about this, or any other work we do at the Ministry of Transportation and Infrastructure, let us know in the comments below. Safe travels everyone!

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