DAWSON CREEK, B.C. – After a Chinook brought unseasonably mild temperatures to the Peace Region, though the forecast is calling for a return to more seasonal temperatures, that means a bigger workload for road maintenance crews in the area.
Caribou Road Services Operations Manager Ken Oakley says that with the wide possible range of temperatures across the Peace Region at this time of year, keeping area highways and roads free of snow, and especially ice, becomes a real challenge. “One minute you’re trying to sand the roads, the next minute it’s melting,” says Oakley. “Of course, we had lots of water last fall, and it didn’t dissipate into the ground or anything, it all stayed on the surface so it’s all freezing on the surface. So when the water starts running on the surface, you can’t get it down through all the pipes because all the pipes are frozen.”
Oakley says that the situation becomes even more challenging when that surface water freezes during sub-zero temperatures through the overnight hours, in some cases creating black ice. Though one would assume that the solution would be to simply lay down salt on the roads, Oakley explained that road crews are limited by the temperature of the road surface itself, not air temperature. “If you think of the road like a block of ice, the frost in the road is down more than three metres right now. As the traffic drives on it, it drives the frost even deeper. When you get the warm air temperature, it doesn’t necessarily warm up that road, because you’ve got that freezer below there keeping the surface of the road cold. Typically about ten centimetres below the surface is what the air temperature was last week.” Since salt is only effective on the roads down to an air temperature of roughly minus four degrees, Oakley says that if the forecast calls for lower temperatures then crews will usually only apply sand and gravel for traction, as the salt is no longer effective below that.