Drivers themselves should be prepared for winter conditions with adequate protective clothing and footwear

control and may be enough to allow the vehicle to claw its way along. On threeaxle units, the driver should also consider using the load transfer or axle lift facility to throw more weight onto the drive axle. However, this is only enabled at speeds below 30 km/h.

Some trucks are also fitted with a differential lock. This should only be used at very low speeds when the truck is going in a straight line, as steering control will be compromised. It is ideal in circumstances where there is a big difference in grip in the road surfaces under each set of drive-axle wheels, but in normal conditions it’s best to rely on the ASR system. If the truck will only move with the diff lock constantly engaged, then it’s probably too slippery to drive safely anyway. In these circumstances, it’s unwise to proceed any further than the next safe parking space.

Modern braking systems use ABS and EBS to control the braking effort through each wheel and in slippery conditions their effectiveness can be maximised by minimising the use of retarders and engine brakes that only impart braking effort through the drive axle.

The foundation brakes, rather than forced down-changes, should be used to shed speed and the truck should not be driven fast enough for brake fade to become an issue.

These systems cannot, however, work miracles: stopping distances are increased by their activation and situations where harsh braking might be needed should be avoided by employing defensive driving techniques.

It is most important to maintain ‘safe space’ in front of the vehicle, so difficult situations requiring harsh brake applications do not develop. ■