Early winter driving


Last night we had the first snowfall for the year, unusually early since this usually occurs in late November. So it was a bit of a surprise for me to look out the window when I woke up and see the snow-covered ground. But it was no surprise to turn on the radio and to hear of numerous car accidents all around the town during the morning commute to work, snarling up traffic.

It seems like over the year some people completely forget how to drive in snow or icy conditions and go barreling along as if the snow does not change anything. The basic fact of physics is that snow and ice reduces the coefficient of friction dramatically, making maneuvers that are safe on dry surface quite dangerous.

Basic winter driving safety practices consist of turning on your headlights whenever it is snowing or raining, keeping a safe distance, not making sharp turns except at low speed, avoiding abrupt changes in direction, avoiding sudden accelerations, and minimizing the use of brakes (driving in a lower gear is a good way of doing this). All these measures (except the lower gear) are recommended at all times but become particular important in winter driving.

During the first few days of winters I drive particularly carefully because I know for a fact that the change in weather will not have registered in the consciousness of some drivers. I keep an eye out for drivers who weave in and out of traffic or are driving too fast and too close to other cars because these are the real dangers, not so much the weather. I suspect that after these drivers have had a few close calls, they begin to realize that it is winter and that they need to be more careful.

Comments

  1. kyoseki says

    I live in Los Angeles and the scenario you describe occurs with even the slightest rainfall (that typically doesn’t occur at all between say March and November).

    LA drivers seem to have two reactions to rain, either drive as though it’s perfectly dry (ie. 20mph over the speed limit 3″ from the bumper of the guy in front) or drive 20 mph everywhere as though the road might jump up and bite them at any given moment.

    As a consequence of these two types of drivers coming together you can map rainfall using the sigalert map of traffic collisions -- “ooh, 8 car collision, must be raining in Westwood”.

    Coming from the UK (and so having extensive wet weather driving experience -- I even did all of my motorcycle training & testing in torrential rain) this is particularly infuriating for me.

    If it ever snows here, I’m walking to work.

  2. lochaber says

    kyoseki>

    I grew up in the northeast U.S., and learned to drive in snow and rain.

    Then I ended up in the So Cal for a bit, and yeah, they have no clue how to drive in the rain.

  3. oldymoldy says

    Sounds like driving instructions from a physicist.

    “LA drivers seem to have two reactions to rain…”
    I’ve been away from LA for a long time now, but spent the first 50 years of my life there. That’s pretty much the same impression I had of driving there back in the late 60’s/70’s.

  4. Tsu Dho Nimh says

    The thing is they drive as fast as they can, so they can get to work before they have an accident.

  5. cottonnero says

    I’ve noticed that the first day of school is a similar, although less severe, phenomenon. Then, after a day or two, everyone remembers to slow down, check for rambunctious and inattentive second graders, or just avoid school areas around 3:30.

    Similarly, power failures and treating dead stop lights as stop signs. That escapes some people, especially when they’re driving on the ‘big’ road of the intersection.

  6. says

    Be careful gearing down in the winter! If you have ABS you can stomp on the brakes and still steer a little, but gearing down can lock up the wheels and put you in an uncontrolled skid. You can fix it easily enough by changing gears or accelerating a little, but you have to be paying attention.

  7. voidhawk says

    Also, don’t drive rear-wheel-drive cars at all. I remember a couple of years ago driving to a party in the snow in a light, nimble little Ford Ka and finding the snow little more than an inconvenience. Whereas the big, expensive Porches and Mercedes were struggling for any kind of grip.

  8. Mano Singham says

    I was not quite sure what you were warning about. If I think the road is slippery, I shift from D (I drive an automatic) to 3 or even 2 if things are really bad. That enables me to control speed better without using the brakes except to come to a sea stop. Is that ok?

  9. vikingatheist says

    Driving around using ordinary tires on snow and ice is utter madness in my opinion
    Thats why we Scandinavians use proper winter tires almost half the year. (And I DON’T mean ordinary M+S-tiers. Those things are hardly any better than regular tires).

  10. kyoseki says

    I think what he’s saying is that while shorter gears force you to slow down, they’re unforgiving; If you break traction at the wheels by downshifting or even just releasing or depressing the accelerator too quickly, you’re not going to get it back unless you spin the wheels up to match the speed of travel -- I once drove up into the mountains here when the snow level came down to under 2000 feet, even in 4wd (my old car was a jeep) maintaining traction in short gears was a challenge and required judicious use of the throttle & clutch to regain traction when the front end broke loose (we wisely decided to turn around after about a mile or two and go to the pub instead, CHP closed the road shortly after we got off the mountain because of the huge number of crashes).

    Taller gears actually make you less likely to break traction -- it decreases the effective torque from the engine at the wheels making you less likely to lose grip under either acceleration or engine braking (using a gear one or two ratios higher than you normally would is actually one of the recommended techniques for riding a motorcycle in the wet) -- but it requires a manual transmission. My current car has monstrous levels of torque so it’s very unforgiving if you balls up a gear change and driving it in the wet is “entertaining” unless you never shift below 3rd.

    Remember also that brakes apply at all 4 wheels whereas engine braking/acceleration only work at the front or the rear unless you’re in a 4wd car, spreading the required force among 4 contact patches instead of just 2 also makes you less likely to lose traction.

    The real key to driving in all inclement weather is smoothness, avoiding doing any sudden moves that would increase the required grip from the wheels making you less likely to break traction. This usually just comes down to observation; If you’re paying enough attention and looking far enough up the road (ie. not just staring at the tail lights of the car in front), you should never have to perform any kind of sudden maneuver.

  11. Acolyte of Sagan says

    Also, don’t drive rear-wheel-drive cars at all.

    Rear-wheel drive cars are much more fun to drive in all weathers, and I have never had a problem driving them in snow or on ice. I once even towed a 4wd Range Rover out of a snow bank with my old rwd Ford Cortina (which possibly said more about the driving abilities of the RR owner than it did about mine, but still….).
    Less experienced drivers with rwd cars can overcome the loss of traction caused by snow and ice in a number of ways: making sure they use proper winter tyres, or at least ensuring their tyres have plenty of tread: deflating the tyres to around 10psi less than their recommended pressure, causing a greater surface area of the tyre to be in contact with the road surface: putting a couple of concrete paving slabs in the boot (trunk) to add down-force to the driven wheels: and finally -- and most importantly -- actually learning to drive properly in adverse conditions.

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