In most of Western Washington and Western Oregon any snow causes either a one or two hour delay to the start of classes. More than one inch will almost always close schools and some businesses. WSDOT and ODOT usually use only sand on the roads to give some traction, however it doesn't melt the snow, and because of the mountains, it is rare for the sun to shine after a "snow event" so that doesn't melt the snow either. One inch of snow can often stay around for a week or more before melting. WSDOT has been experimenting with using salt water, but it is not wide spread, they both use diluted de-icer in some major areas, but it to is not wide spread.
Portland is the worst when they have snow, as after 3 inches they usually ban travel in the city without chains, the light rail often shuts down, and busses run 24/7 in a vain attempt to keep the roads clear.
In Michigan on the other hand, I was around when it snowed 9" overnight. Nothing closed and nothing was delayed. They use salt which melts the snow and ice, plus the sun comes out and warms the pavement.
TEG
