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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Autos

Winter driving considerations

Hopefully, we’ve honed our winter driving skills during the December appearance of snow-covered roads.  The basics of slowing according to conditions, effecting gentle input to steering, throttle and brakes, and leaving extra space around your vehicle should be habit by now.

But there are other intricacies of winter driving that we must practice to remain safe.

Of course it makes sense to keep your vehicle maintained for winter-readiness with adequate oil, coolant, battery, tires, brakes, et cetera.  Additionally, it can be invaluable to have an emergency “trunk kit” consisting of items like blankets, snacks, water, flares, and a first-aid kit in the event of vehicle break-down or road closures.

Overpasses, bridges and shady areas may be icy even when the rest of the road is not.  Though this is nearly universally known, remembering it is the key.  Drivers are routinely caught off-guard by this phenomenon.

Get to know your brakes by testing controlled and “panic” stops in a safe area absent other vehicles.  The majority of vehicles now have antilock brakes, which require drivers to keep a firm, steady pressure on the brake pedal for proper operation.  The “old school” practice of pumping the pedal renders antilock systems ineffective.  They are designed to achieve an efficient stop in slippery conditions by averting impending wheel lockup while sustaining steering control.  The ratcheting noise and pedal pulsation while activated with a steady foot on the pedal is normal and indicative that skidding is being averted.

While travelling Washington mountain passes, drivers may encounter signs displaying various messages touting traction requirements.  The first warning, “Traction Tires Advised” prohibits oversize loads and recommends that vehicles have tires rated “M & S.”  The next level, “Traction Tires Required,” requires that passenger vehicles are equipped with “approved” traction tires with “M & S” rating or a mountain/snowflake symbol.  Under this condition, chains are required on vehicles over 10,000 pounds gross vehicle weight. 

The final mountain pass signage reads “Tire Chains Required.”  This designation means chains must be affixed to the drive wheels — two front wheels for front-wheel drive and two rear wheels for rear-wheel drive.  However, there is an exemption to this requirement:  Four-wheel drive and all-wheel drive drivers need not install chains if all wheels are in gear and if equipped with approved traction tires.  The “catch” is that, to be legal, chains for at least one set of drive wheels must still be carried in such vehicles.

By the way, for traction tires to be “approved,” in addition to the proper sidewall designations, they must carry at least 4/32nds (1/8th) of an inch of tread depth.  The tread depth for a tire to be legal in other conditions is 2/32nds (1/16th) of an inch.  Personally, I think that tires should be discarded as they approach 3/32nds of an inch of remaining tread, and not be considered for winter use when tread diminishes beyond 6/32nds.

For vehicles with limited wheel well clearances, alternative traction devices, known commonly as “snow socks” are now available and approved for use.  These textile tire covers are effective for traction increase, and their manufacturers claim easier mounting and dismounting as compared to metal chains.

If you are not confident to drive in the worst winter conditions, it’s best to delay your trip or seek alternative transportation.  Pay attention to weather forecasts and road condition reports, and be prepared when venturing out.

Readers may contact Bill Love via e-mail at precisiondriving@spokesman.com.