I worked in two-way radio shop after retiring from home inspection biz. When they started using Mag chloride on the freeway, I84, I started finding eaten up wiring that caused a number of failures on cars and trucks. I'm not sure how much the de-icer helps, we always have a huge number of truck accidents on the passes that close the freeway. A lot of truckers like to drive w/o chains too. So it's not just Portland. Me, I stay home. My doc wanted to send me to VA Walla Walla for some test which would have meant going over the pass yet again. Nope, see ya in the spring doc!!