The single most important thing you can do to drive safely in snow, ice, and cold temperatures is to fit a set of studless winter tires to your car or truck. But even after you’ve done that, the season’s inclement weather still calls for a little knowledge, smart decision making, and common sense. I’ve driven the frozen Baltic Sea, the icy Siberian tundra, off-road in deep snow through Iceland’s mountains, and the snow-covered streets of Manhattan. Let’s make you a better winter driver.
Know When to Stay Off the Roads
After winter tires, the best advice I can give you is simply to stay home and avoid driving in serious weather. If it's bad enough that driving is dangerous, then it’s probably not worth getting on the road.
How many drivers in Portland, Oregon, wish they’d heeded this advice last month? That city received just two inches of snow, yet its drivers had hundreds of crashes, were stuck in their cars for hours, and some of the worst pile ups took days to be cleared. I bet most of those who are dealing with insurance companies and impound lots right now wish they’d left their cars at home that morning, taken an alternate method of transport home that night, or just sucked it up and gotten a hotel room. Your $500 insurance deductible is about five times the price of a decent hotel room in the city.
Snow, ice, slush, rain, and even cold temperatures all conspire to reduce the friction between your tires and the roadway. You need that friction to go, stop, and turn. Lower speeds require less of that limited friction to stop and corner and will also allow you more time to make potentially life-saving decisions.
While you’re at it, increase the space between you and other vehicles as well. Instead of the usual two- to four-second following interval you use in good weather, increase that to eight to ten seconds. Again, that compensates for your car's reduced braking ability, while increasing the time you have to react.
No matter how long you’ve had your license, you’ll benefit from practicing your winter-weather driving skills. Finding a safe place to do so is key. It will allow you to make mistakes that won't damage your vehicle, your health, or someone else’s property. A big empty parking lot works, as does a quiet cul-de-sac or an empty field (just beware of under-snow obstacles when you're off road). Once you're ready, see what it feels like to accelerate, apply your brakes, and corner.
Because you're working with reduced friction, winter weather reduces the speed with which you can accelerate and brake. Just pumping the pedals with the usual force may overwhelm the tires' available grip, causing your wheels to starting spinning while accelerating or lock up while braking. Either scenario reduces your ability to control your vehicle. So practice gingerly applying the throttle from a dead stop, and gaining momentum without inducing wheel spin. Once you have a feel for that, practice it on an incline, which can be even harder. It's also vital to get an idea of what it feels like to brake in slippery conditions. Practice coming to a controlled stop in as short a distance as possible.
You should also learn how to correct slides, which you can encounter going around a corner. Switch off your Traction Control and Stability Control (more on that shortly), drive in a circle of a set size at a speed below where you start sliding in a big, open area. When you’re ready, stab the gas pedal to initiate a slide. By simply looking where you want to go, you'll naturally steer in a way that should achieve some measure of slide control. After a few fun spins, try consciously steering toward where you’re looking. The last piece in the puzzle is keeping the car balanced by holding even pressure on the gas pedal.
What you're trying to do is help the tires regain traction, while steering the car away from obstacles and keeping it on the road. Even while your car is in a slide, the spinning tires have some effect on the car's direction of travel. The idea is to maintain that, while allowing them to clear the slippery portion of the road, and regain traction on their own. Rapidly letting off the throttle, or applying the brakes will actually exacerbate the slide by altering the car's weight balance, or locking the wheels.
All cars slide a little differently. Front-wheel-drive and all-wheel-drive cars tend to understeer (boring, easy to control). Rear-wheel-drive cars tend to oversteer (exciting, difficult to master). (Here's a great explanation of how understeer and oversteer differ.) The weight distribution, tires, differentials, and electronic driver aids are other factors. It’s vital to practice slides in any car you’ll be driving regularly through winter weather, so you know what to expect, in what conditions, and how to control it.
Throughout all of this, it's vital to also understand that winter weather conditions vary greatly. There's different kinds of snow, different kinds of ice, and all sorts of mixes of the two, along with other factors that will change how your car behaves.
Car Technology: How It Works and How It Can Help You
All-wheel drive differs from four-wheel drive in that it can instantaneously redirect power to any or all of your wheels in slippery conditions. But unlike a 4WD, an AWD vehicle cannot lock the speeds of the front and rear axles together.
If your car has all-wheel drive, you’ll have an easier time accelerating in slippery conditions. But AWD does not improve your car’s ability to brake or turn. And be warned: because braking and turning are more important for safety than accelerating, your ease of acceleration can lead to exaggerated confidence. It doesn’t matter how many wheels on your car are allegedly driven (when things get slippery, it’s actually just one), we all rely on the same four contact patches to slow or turn. My advice: don't rely on the car, rely on winter tires.
The way AWD and 4WD function, and the ways in which they differ are complicated. I think we've done a pretty good job explaining that in detail here.
ABS keeps your wheels from locking when you slam on the brakes. This is important because, in winter weather, there's less friction between your tires and the surface you're driving on—and locked wheels eliminate your ability to steer. This feature does not help you stop in shorter distances. One of the most important skills you can practice in a vehicle is threshold braking, where you hold the brakes just on the edge of locking up, in order to achieve maximum stopping power. This is an advanced skill; one you should likely learn in a high performance driving school such as Skip Barber. If you don't have the time for advanced driver training, then you’ll simply need to rely on ABS to make up for your lack of ability. You’ll feel the brake pedal pulse when they're doing their job: this is just how ABS works.
Unlike AWD, 4WD locks the speed of the front and rear axles together, which means torque has to overcome the grip available to both axles before it can induce wheel spin. If you are driving on a consistently slippery surface (deep snow, a frozen lake, etc), then you’ll benefit from employing 4WD if your vehicle is so-equipped. But be warned: Because the front and rear axles need to spin at different speeds in corners, engaging 4WD while going fast on pavement is a bad idea and can damage your vehicle or cause you to lose control. If you are driving on a mixed surface, with patches of pavement and snow, then you should probably stick with two-wheel drive, only employing 4WD if you are stuck, or risk becoming so. Every 4WD vehicle engages its front axle differently; consult your owner’s manual and learn how your car works. Again, consult our explanation of how 4WD and AWD work if you want to learn more.
Traction control monitors wheel speeds, killing power when the driven wheels begin to spin up. This can take some of the guesswork out of winter driving; you don't have to think so much about how much throttle to apply. If your car is less than 20 years old, it probably has TC. Leave it switched on for most winter driving, but if you get stuck and feel you may benefit from some wheel spin to get out, know how to turn it off. Here's more on how traction control works.
You’ll find a variety of acronyms and propriety names for this technology, but it always works the same way. By using the ABS to monitor and individually adjust wheel speeds, a computer is able to help prevent the car from spinning, or otherwise going out of control. This is the most effective safety technology since the seatbelt; it delivers the non-crashiness in bad weather, or through ham-fisted driving that most people unknowingly attribute to AWD. Leave it on at all times, unless you’re practicing in safe, controlled conditions. Here's more on how stability control works.
That Snowflake Button Next to Your Gear Selector
On most modern automatic cars, you’ll often find a button with a snowflake on it, located somewhere in the vicinity of your gear selector. It tells the transmission to pull away in second gear, rather than first. Manual drivers, you can probably learn something from this. Gears multiply an engine’s torque. In slippery conditions, first gear may apply too much torque for given traction. Each gear multiplies torque less as you shift up, so second gear may allow you to pull away, where you were just spinning your wheels in first.
If you drive a 4WD truck, you may have the ability to lock one or both differentials. Where 4WD locks the speed of the front and rear axles together, locking diffs make the speed of the wheels on the axle even. This maximizes available traction, but again, you should only use these while driving on slippery surfaces and only at low speeds. Locking your diff(s) might help you get unstuck, but don’t use them to drive around once you’re unstuck. Again, consult your owner’s manual for which button, knob, dial, or lever does what. If you're confused about what differentials do, watch this video.
Stuff You Should Have With You
Trapped in your car for hours because drivers in Portland can’t handle two inches of snow? You might need to switch your engine off in order to conserve gas. In which case, your heat won’t work. I carry a Rumpl Down Puffy Blanket for just that purpose, but anything works.
Should your vehicle get stuck, you'll need to excavate its driven wheels (the back wheels for a rear-wheel drive, etc.), and put something that will provide traction underneath them. Whether that’s kitty litter, your floor mats, or some rocks, you’ll need a shovel to dig your tires out first. I find a rectangular garden spade works best in snow and ice. The larger the shovel you carry, the easier it’ll be to use.
Driving to work in a pair of expensive loafers? Man, it’d be difficult to walk a mile for help if you get stuck. An old pair of serviceable, waterproof boots belongs in your trunk at all times.
At Least Half a Tank of Gas
There's no need for jerry cans, just don’t let your tank get below half-full if inclement weather is expected. That way, you can avoid long lines at gas stations and wait out the dreaded traffic jams.
A Phone Charger
Carry a battery charger or one that plugs into your cigarette lighter. You wouldn’t want to get stuck in a traffic jam without the ability to complain about it on Facebook.
One Of Those Ice Scraper/Brush Things
It’s vital to clean all accumulated snow and ice off your car before driving. It’s obvious why you need to dig out your lights and windows, but leaving snow on the roof or hood could also lead to loss of vision while driving, as it shifts due to braking, acceleration, and wind.