delays for Snoqualmie to Vantage.
The colder weather and snow on the passes prompted suggestions for things we ought to start doing. Since the North Cascades is a mile high, it gets winter a thousand feet sooner than Stevens or Blewett.
The pass reports for all the passes start on November 1. If there are restrictions imposed before that, they’re posted on the mountain pass page. If there’s snow, but not creating conditions requiring restrictions, the message stays what it has been all summer, “no restrictions”.
At 8 this morning the real time weather station at Rainy pass showed 5” of snow on the shoulders and 23” was the total at the U.S. Forest Service’s Washington Pass Overlook weather station. (which is about a quarter mile east and several hundred feet higher than highway.) Temperatures at both were above freezing and the forecast was for sunshine until late this afternoon.
Some folks suggested we install traffic cameras. With no power, no microwave, phone or cellular service on a pass which is closed for 5 months of the year, it would require a gas powered generator and satellite connectivity – making the installation itself and the maintenance and operation prohibitively expensive.
It’s been suggested we post an employee in a snow plow at the summit to provide direct reports, but that is complicated as the employee would have to drive 30 minutes or more to be able to radio or phone in an update. It would also require more than one employee to cover even daylight hour reports 7 days a week. That too, just doesn’t pencil out for an average daily traffic count that after Labor Day may not exceed 100 vehicles on SR 20.
For these weeks between the beginning of fall and the end of November when avalanches usually close SR 20, we suggest travelers:
Together they can provide a hint of what’s happening up there and what’s coming.
Behind the Curtain
Anti-icer/deicer/sand & salt
Not surprising, some of the winter correspondence received this week included questions about the chemicals used to melt snow and ice.
Here’s a primer we have prepared to answer most questions about the snow and ice program. you may wish to save it!
WSDOT transitioned from sand to a chemical program beginning in the 1990s. Sand is still used, but now primarily as a traction aid on slick spots and when temperatures are too cold for salt or anti-icers to work. The resource agencies don’t like sand. It creates clouds of particulates when the roadways dry affecting air quality. It can also clog fish spawning beds when it gets into streams and rivers. For WSDOT’s part, it doesn’t melt ice and it is expensive to clean up in the spring as it must be disposed of in approved waste sites.
The snow-belt states and provinces in North America use salt, liquid anti-icers, or both as the staple of their winter programs. Wintertime mobility has been vastly improved for cars and especially commercial truckers.
Our Snow and Ice Program is proactive rather than reactive, meaning we strive to prevent the formation of ice or compact snow on road surfaces through application of anti-icers prior to storm events as opposed to dealing with compact snow and ice covered highways with a layer of sand on top to provide traction. Bare and wet pavement as soon as possible after storm events is our goal. Sand alone can’t provide that outcome.
Chlorides (salt and liquid deicers) are indeed corrosive to vehicles. It’s why we encourage drivers to wash their vehicles after they’ve driven on treated roads when the temperature goes is above freezing (nothing rusts below freezing, so don’t worry about washing until then.)
All of our liquid chloride products are corrosion inhibited to the Pacific Northwest Snowfighter (http://pnsassociation.org/) standard of 70% less corrosive than rock salt. Even when we apply straight salt, we apply corrosion inhibitors at a rate of at least 10 gallons per ton which actually makes salt less corrosive than salt!
We have studied anti-icer impacts to roadside vegetation and have worked with a Forest Pathologist to identify the likely causes of “needle browning” on trees on our mountain passes where chloride use is prevalent. That vegetation damage is a product of several factors which can include anti-icers. For trees next to the guardrails, browning is only on side of the tree and is caused by damage from that 40 mph curl of snow from a snow plow. Those trees usually turn green again by late summer. Trees that are brown all over and further from the road are victims of bug infestations or disease, not salt. (The calcium chloride we use most often in this region is a weak version of the product apple and pear orchardists apply every year to restore chloride to the soil that trees need to form fruit-hardly a poison. You already know the rock salt is the same as what’s in the salt shaker on your table.). We do sample roadside soils and water in many locations twice a year to measure chloride concentrations. In the 20 years since we started, levels have been well within safe ranges established by EPA, Ecology, Fish & Wildlife and others..
WSDOT is a nationally recognized leader in the study of chloride corrosion to vehicles and infrastructure, the environmental impacts (and the prevention of) of salt and anti-icers, and the study of comparative benefits of various anti-icing products. We remain firm in our conviction that the use of these products is cost effective, environmentally sound, and provides a superior level of service for wintertime travel.
Below are links to our research for snow and ice material related topics:
http://www.trb.org/Main/Blurbs/169520.aspx - Strategies to Mitigate the Impacts of Chloride Roadway Deicers on the Natural Environment
http://www.trb.org/Main/Blurbs/158876.aspx - Guidelines for the Selection of Snow and Ice Control Materials to Mitigate Environmental Impacts
http://www.wsdot.wa.gov/Research/Reports/700/796.1.htm - Identification and Laboratory Assessment of Best Practices to Protect DOT Equipment from the Corrosive Effect of Chemical Deicers
http://www.wsdot.wa.gov/Research/Reports/700/759.1.htm - Investigating Longevity of Corrosion Inhibitors and Performance of Deicer Products Under Storage or After Pavement Application
WSDOT is also a charter member of the Pacific Northwest Snowfighters Pooled Fund organization (http://pnsassociation.org/) which is dedicated to the study and qualification of snow and ice fighting materials for agency use. It is the internationally recognized premier organization for such work, and WSDOT is the host state. We are also a member of the Clear Roads Pooled Fund (http://clearroads.org/) which is dedicated to the study of all things winter operations related for state DOTs including:
Cost-Benefit of Various Winter Maintenance Strategies: http://clearroads.org/project/cost-benefit-of-various-winter-maintenance-strategies/
Snow and Ice Control Environmental Best Management Practices Manual
Establishing Effective Salt and Anti-icing Application Rates
We are always available to answer questions about our Snow and Ice Program.
“Drop, Cover, and Hold On”
Did you climb under your desk at 10:20 a.m. Thursday? We did; joining thousands across the state participating in The Great Washington ShakeOut.
Safety is WSDOT’s first priority and we use the ShakeOut to test our evacuation and accountability procedures – such as how effectively we can account for all our employees after an earthquake. This is a crucial step after any disaster and practicing it ensures it will run smoothly when we need it.
The Cascadia Rising Earthquake Preparedness drill earlier this year illustrated how important it is for all agencies, and individuals, to be prepared for disasters. For more resources, checkout the Washington State Department of Emergency Management’s Earthquake Country brochure.
Until next week,
WSDOT North Central Region Leadership Team
If you have any questions on items in this NewsBrief, or other transportation issues, please let us know. Call (509) 667-3001 or send an e-mail.