Photo: Contributed

Throughout the winter, some of BC's highways are closed from time to time. Sometimes the closures are due to weather sometimes the closures are due to motor vehicle incidents, sometimes the closures are due to maintenance. 

Over the weekend, the Ministry of Transportation and Infrastructure shared some raw video of avalanche control work being conducted near Highway 1, east of Revelstoke. 

A look from above at today’s avalanche control work at #BChwy1, east of #Revelstoke. Maintenance crews were on hand to clear all that snow.
As winter ❄️ weather amps up, so will avalanche control measures. Please drive safely and with patience. #shiftintowinter pic.twitter.com/iBitp4IeHp

— BC Transportation (@TranBC) December 15, 2018

The section of Highway 1 can be treacherous and is often closed throughout the winter. 

For example, on December 12 that section of highway was closed due to a motor vehicle incident. It was reported that a 148.5 km was closed from Revelstoke to Golden. 

Shelley Bird, public relations and communications officer for Mount Revelstoke and Glacier national parks provided Castanet with an explanation as to why such a long stretch of highway should be closed when an incident occurs in that area. 

 "When you mention that a 148.5 km stretch of road has been closed due to the incident, many people may not understand the significance or reasons behind this type of closure," Bird wrote.
 
"It might be worth noting at some point that highway closures are more common in winter between Revelstoke and Golden due to the avalanche risk," hence the work being done over the weekend. 

"When an incident occurs in this area in winter, traffic has to be managed to ensure that vehicles are not stopped in avalanche terrain. In the 40-km stretch through Rogers Pass in Glacier National Park alone, there are 134 avalanche paths that can reach the highway. There are also many other avalanche paths outside the park. Throughout the highway corridor, there are designated traffic holding areas where vehicles can safely park during a closure. Longer closures will generally hold traffic in Revelstoke and Golden to ensure the safety of highway travellers. Closures due to highway incidents will vary in length depending on the nature of the incident and safety considerations for everyone travelling through this corridor."

Bird explains that sometimes closures also occur for proactive avalanche control measures to bring down small, more frequent avalanches to reduce the snow load and thus the risk of natural and/or large avalanches impacting the highway. 

"This improves safety and reduces the length of closures required for avalanche control and clean up," she wrote.
 
"Throughout the year, Parks Canada and our partners along this section of the Trans-Canada Highway, take active measures to protect the safety of highway travellers and keep this major national transportation corridor open. Parks Canada’s trained professionals work 24-7 throughout the winter performing avalanche control and road maintenance in Glacier National Park. 

Since 1961, Parks Canada and the Canadian Armed Forces, under Operation PALACI, have partnered to run the world’s largest mobile artillery avalanche control program. A recognized international leader in avalanche safety, Parks Canada’s avalanche forecasters and technicians closely monitor weather, snowfall and snowpack to assess avalanche hazards." 

By understanding the stability of the snowpack, Parks Canada Avalanche Forecasters are able to determine when avalanche control is required. 

The highway and railway will then be temporarily closed while Parks Canada and the Canadian Armed Forces initiate avalanche control measures.