Autumn approaches and the leaves begin to turn. The morning dew covers the grass and the cars with water droplets that catch the early sun. As the days shorten and the night grows longer the falling average temperature leads to the first frosts of winter.
Driving starts when you open the car door and if your thoughts aren’t with what you are doing the road surface may take control before you even touch the steering wheel. Two things you need to do when a light rime replaces the soft water covering your car. First observe the surroundings, look at the road surface and then start scraping. Second, after the glass and the mirrors are clear, drive off as normal. Do not drive as if the road is covered in ice, unless you have already determined that it is because frost does not equal hard ice.
If you drive as if on eggshells you will notice a couple of things fairly soon. One is that everyone else is not doing what you are doing and are driving much faster than you are and the next thing is you’ll be late for work or your destination will seem farther away.
You need to find out if the road is slippery and the easy way to gauge this is to drive normally at first to discover the limits of grip that your tyres have and then you can adjust your style to match the conditions.
Driving out of my road is an everyday occurrence which means I know how sharp the bends are and how steep the small hill is up to the first stopping place where I join a larger road leading off the estate. By the time I have come off the first bend I know the amount of traction my vehicle has on the frosty road and can then drive safely within that limiting factor.
Here’s a thing – actually you will have more grip than you think you have for a few reasons. One is that frost turns to water usually purely because you drive onto it. I know that might seem an odd notion but it is simple physics. The pressure of the tyre and vehicle cause heat to be generated which at slow speeds melts the ice particles. Don’t believe me? Again, try observing other vehicles driving over frost and see the wheel tracks behind them being melted water rather than frost. Another reason is that your tyres have gaps between the tread designed to allow water to escape from beneath the tyre.
This pattern also allows the frost, which is actually soft, almost like snow, to move out from under the tread into the gaps again caused by the pressure of the weight of the vehicle onto the frost particles. A third reason that most people don’t take into consideration is that when you compress soft water, i.e. icy particles, they harden and doing this with the tread blocks of a tyre as you corner gives you grip you don’t have on a wet road. The process is overlooked and I wouldn’t recommend relying on this to corner faster but the tiny walls of hard packed frozen water help to stop slipping sideways at slow speeds.
The final reason you have more grip than you think you do is so basic that I’ve not heard anyone explain it but think about this for a minute – how fast do you drive when you set off at the beginning of your journey? Are you flooring the gas pedal and taking the turns at the edge of grip? Not unless you are slightly insane. What everyone does is to drive within yours and the vehicle’s limits, in fact not just within but with a safety factor somewhere approaching a tenth of how fast you could drive on normal dry road if you wanted to. Because of this you mostly do not drive any different from normal which is why that is how I begin my journey and that, more than any other factor tells me what the driving conditions are because by the time I have taken those first turns and driven away from a hill start position I know that I don’t need to slow down at all for my normal rush hour commute which is driven at way below the capacity of my driving style and the cars ability to stay on the road. Of course, there are a very few days when driving normally is unsafe but the fact remains that I have tested the grip and know how to drive the conditions that prevail.
There is one concession I make which is, as usual, not for my driving but the half-awake drivers behind me. To give them more time to react I brake a little more softly and keep looking in the mirror to check out the reaction times of those following.
Black ice does present a slightly different challenge which is simply that often black ice appears in small patches on fast trunk roads, usually in low lying stretches due to them being frost pockets, if you hear traffic announcements warning of black ice don’t immediately hit the brakes to reduce speed but do so gradually and don’t make any sudden movements with the steering wheel. If you feel the car is slipping, then maintain a soft but firm grip and don’t turn the wheel at all until you feel confident of the grip.
Any low lying or unsalted roads can have black ice and the most lethal is on a hill where there is a slow running spring allowing water to seep out onto the road surface very slowly and in really low temperatures turn to ice. This may not be invisible like true black ice but can readily be disguised if the rest of the road surface has a light frost covering.
Remember this; if the road surface is in doubt or you run onto a frosty surface you didn’t expect slow down sloooowly.