Precision driving: Getting through mountain passes

There are more than 15 mountain passes in Washington state, and dozens more in Oregon, Idaho, and Montana. This season, we auto adventurists may need to pass through those wintry routes amid brutal conditions as we go visiting and recreating.

Here in Washington, our scenic North Cascades route is closed for the season, along with Cayuse and Chinook passes. The Washington State Department of Transportation, however, will endeavor to keep the remaining mountain roadways open for business. The most prominent Washington pass, Snoqualmie, carries the largest volume of traffic, and gets the most attention from road crews.

Beginning in November 2005, WSDOT started a winter procedure of managing mountain pass traffic over Snoqualmie. Traffic Flow Management adjusts the number of vehicles per hour that cross the mountain pass. This reduces the risk of collisions, plus creates space for maintenance crews to safely remove roadway snow and ice.

The program, which has been employed with success in other states, goes into effect when weather forecasts call for six or more inches of snow in a 12-hour period. Here’s how it works, as described by the transportation department: “During the preparation phase, a few miles before the summit,WSDOT crews reduce the three approaching lanes to two lanes using signs and other equipment. When the snow accumulates at the summit, and if traffic volumes are heavy enough (generally a rate of 800 vehicles per hour), the two lanes may be reduced to a single lane. This reduction takes place in a relatively flat section of roadway and at an altitude below the heaviest snowfall. In fact, it may not be snowing at all in the reduction zone. After a short distance, the roadway is expanded back to three lanes; the single lane of cars re-entering these three lanes will naturally space themselves to allow for a smooth and continuous trip over the summit.” Fairly simple, and it works!

In winter, the WSDOT may also issue three different warnings: 1) Traction tires advised, 2) Traction tires required, and 3) Chains required. Traction tires must have at least 4/32 of an inch of tread remaining ( 2/32 of an inch more than the normal legal minimum), and have a sidewall designation of “Mud and Snow,” “M+S,” “All Season,” or have a “Mountain/Snowflake symbol.” The “chains required” designation applies to all vehicles except all-wheel drive — but these motorists, like others, are still required to carry chains when crossing passes. Both link and cable chains are approved.

A chain installation assistance program is making its debut at Snoqualmie this year. For a $25 fee, permitted businesses and individuals will install and remove motorist-owned tire chains. Drivers will see specific locations to purchase this service. Chain installers cannot sell tire chains, but they offer installation expertise, along with chain repair and accessories. Fees for other services are $10 for removal, $3 for elastic-cord chain tighteners, and $5 to repair broken links.

These procedures, coupled with diligent snow removal and the spreading of sand, salt, and liquid melters, show that the state has an earnest interest in our travel and safety.

If you embark on a winter road trip, be sure to know your vehicle, and have it in top operating condition. Tend to items such as battery, lights, charging system, engine oil, heater/defroster, antifreeze, tires, and brakes.

Additionally, you should consider carrying the mountain pass winter basics: chains, small shovel, jumper cables, tow strap, sand, flares, blanket, gloves, boots, flashlight, food, water, first-aid kit, and cash.

Our inevitable wintry conditions require maximum driver attention — stay off the cell phone while driving alert and sober. And finally, some winter driving tips directly from the WSDOT:

“Drive with your headlights on.

“Slow Down! Give yourself extra time to reach your destination when roads are slick. If at all possible, do not drive when the roads are icy. Consider delaying your trip.

“Leave room for maintenance vehicles and plows — stay at least 15 car lengths (200 feet) back and don’t pass on the right.

“Watch for icy surfaces on bridges, even when the rest of the road seems to be in good condition.

“Look farther ahead in traffic. Actions by other drivers will alert you to problems and give you extra seconds to react.

“Trucks take longer to stop, so don’t cut in front of them.

“Don’t use your cruise control or overdrive when it’s freezing (or colder).

“Don’t get overconfident with four-wheel drive. It helps you get going quicker but won’t help you stop any faster.

“Don’t pump anti-lock brakes. The right way is to “stomp and steer.”

Let’s all stay safe, and enjoy the holiday season.