Howitzers. Propane dragons. Sonic booms.
There is no shortage of ideas on how to keep snowbound Idaho 21 open during the winter.
But most are costly.
And the main road linking Boise to Stanley, Challis and parts of Montana does not carry enough traffic to justify a major expense, the Idaho Transportation Department says.
But the annual problem is not going away. In fact, it takes on new urgency this year. Avalanche season between mileposts 94 and 105 arrived a month early.
The department will hold three public meetings next month with hopes that someone can come up with a cheap alternative. No one has yet.
“They are very expensive solutions,” said LeRoy Meyer, District 3 engineer at the state Transportation Department.
“The traffic volumes are on the low side, and we have to consider safety. We do not want anyone to get hurt up there, and we are very concerned about that.”
Keeping the winding road clear is a challenge.
Fifty-four “high-hazard” chutes, mostly on the west side of the canyon, can funnel snow down to the road. One chute is more than a third of a mile long. Piles of heavy snow, some 28 feet thick, and logs have been known to crash on the road.
Last June, the department’s board of directors toured the canyon.
They looked at the chutes, mangled guard rails and even some high water marks, where avalanches falling from one side of the canyon crossed the highway and surged as high as 300 feet on the other side.
“There is a lot of energy in these slides,” said Paul King, assistant to the District 3 maintenance engineer.
Snow slides buried the road Dec. 5. It reopened Thursday.
On Friday, after a foot of fresh snow blasted the area, highway officials issued another avalanche warning.
Crews are permanently assigned to clear snow from the stretch of road parallel to Canyon Creek, from Grandjean to Banner Summit.
At their meetings next month, officials will describe some ways Idaho 21 could be kept open. One method involves the use of snow sheds.
These are concrete tunnels for cars to drive through while the avalanche passes harmlessly overhead.
The main reason costly alternatives are not under consideration on Idaho 21 is the small number of vehicles that travel the road during the winter.
In the past five years, the average daily volume ranged from 91 vehicles during the winter of 1992-93 to 119 vehicles during the 1994-95 season.
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