Driving In Winter Conditions

Winter conditions can be unpredictable, however most of the techniques which are required in cold environments are pretty much common sense:

• Keep speed as low as practically possible
• Increase the distance between cars, corners, junctions and any other obstacles
• Brake early into corners
• Be prepared for understeer and oversteer
• Be prepared to use ABS or avoidance braking techniques
• Top up washer fluids and antifreeze

Many sites have already published which deal with the above issues well, so if you need more information, try a Google search. This article discusses some of the more advanced safety based driving techniques for winter driving. 

Introduction to winter driving techniques

The enemy to cold weather driving is wheelspin (under acceleration) or wheel slip (during braking). There are now many computer controlled systems which can control these actions to a limited extent, however there is no substitute for careful driving. Investing in a vehicle with ABS is the single most effective method of increasing your safety in slippery conditions. Traction control will control wheelspin to a limited extent, but bear in mind that such systems are reactive, which means you'll have to be in a certain amount of trouble before they will start to operate. Much better practice is to avoid the problems to start with.

Accelerate gently and progressively.

• Change up sooner rather than later, pull away in second gear if possible, and use the highest practical gear at all times. This reduces the torque at the wheels and will reduce your wheelspin – also a useful trick when trying to climb a slippery hill.
• Avoid any sudden driver inputs (such as steering, braking, acceleration, gear changes etc).
• Brake soon, and gently. Be prepared to ease off the brakes (if you do not have ABS) in order to steer.
• If you do have ABS, do not 'pump' the brakes – keep a firm pressure on the pedal for maximum effectiveness
• Be prepared to ease off the accelerator to reduce understeer, or steer into the slide to counter oversteer. Please click on the links for more detailed information on recovering from these situations.

Tyres

Depending on the severity of the conditions, it may be worth considering specialist winter tyres. These vary from a Mud and Snow (M&S) rating through to studded tyres for icy roads. Surprisingly, with the correct tyres fitted, driving in quite severe conditions can become remarkably easy – you just have to pay a visit to Finland or other northern countries in the Winter for a demonstration.

Stopping distances in varying winter conditions

Figure 1 shows the dramatic difference in braking distance when on black ice compared to normal tarmac conditions, it's well worth bearing this in mind when driving in the winter.

Figure 1: Stopping distance vs speed for dry asphalt and black ice

Source: http://www.csgnetwork.com/stopdistcalc.html

Table 1: Friction conditions from dry asphalt to black ice