I grew up on the prairie where it gets down to -40 in the winter. The last 4 years I lived there I did the commute to the city, 45 minutes to town, 15 minutes in town. The same on the way back.
The times I saw the most accidents: Fall and Spring. On days that got warm enough to melt snow and ice followed by nights that got cold enough for ice to form I’d see the results the next morning. Cars and trucks off the road in many places. And as often as not this would happen in stretches with no turns or curves. At first I was perplexed but then I read a Volvo brochure and it all made a kind of sense. More about that at the bottom.
Anyway, now I live in the mountains. And it snows here too. Like last morning … I had to go to Trail BC (about an hour or so) and the roads were snowy. I ended up diverting to Castelgar on the way there and back to pick up a friend at the airport. By the afternoon I’d put in 3 hours of snowy, slippery mountain driving. Luckily I stayed on the road – I had no worries with good snow tires and 4 wheel drive. And fortunately I did not get pranged by anyone though I came close to piling into the backend of a semi along the way. You can see that in the video below. As well as the aftermath of two off the road single car accidents.
Those happened along the valley of the Columbia River. In the day time it’s a few degrees above freezing and there’s a moisture in the air. At night I’d imagine black ice is all over the roads.
And that Volvo brochure? In it they were going on about the features in their vehicles and one of them was a Do-Not-Auto-Shift switch for the Automatic transmissions.
Why would they have that you ask?
Well you can drive and maneuver on icy surfaces as long as your wheels don’t lose traction. You lose traction by holding the brakes on all of a sudden. The wheel stops moving and a slide begins.
You also lose traction if your wheels just change speed quick enough. Like when you find you are on bad ice and you slow down, way down, and somewhere along the way your automatic transmission shifts down a gear. And the torque on the drive system is strong enough that this new engine RPM, it’s now higher, is enough to break traction. And your car starts to slide and to you it doesn’t make sense – you haven’t DONE anything! So you sit there confused OR you compensate (but because you weren’t quite sure why the slide was happening you over compensate). And soon your vehicle is off the road and heading for the ditch.
Gotta love Standard Transmissions 🙂