Drivers in South Australia must contend with a variety of road conditions. In some cases, minor changes to your driving style are all that's necessary, but some situations rely on strict road rules to keep everyone safe. If you're a truck driver, you need to understand how Road Rule 108 applies in South Australia. Find out more here.

When Road Rule 108 applies

Steep hills present a serious hazard for truck drivers. Ascending a steep hill is often slow progress, but drivers could face a catastrophe when descending the other side. If you lose control of your truck as you drive down a steep hill, the possibility of damage and injury is significant. Foot brakes alone are not enough to control a descending truck, as they can easily overheat.

As such, when truck drivers navigate a long, steep descent, Road Rule 108 applies. Road Rule 108 applies to any bus with a seating capacity over 12 passengers. The rule also applies to any vehicle with a Gross Vehicle Mass over 4.5 tonnes.

Compliance with Road Rule 108

When Road Rule 108 is in effect, you must decrease speed and switch to a low gear. By doing this, you will switch the truck into the right gear for the descent, removing the need to use the foot brake. During the descent, you should then use the engine or exhaust brake to carefully control the truck.

How you will know Road Rule 108 is in effect

Road Rule 108 comes into effect where you see a special sign that say 'trucks and buses must use low gear.' These signs will appear before you reach a dangerous descent. The sign will also often tell you how long the conditions will last for. In some cases, the Road Rule will apply for several kilometres.

If the sign doesn't tell you the length of applicable road, you must comply with Road Rule 108 until you see a second sign that says 'end truck and bus low gear area.'

Penalties for breaking Road Rule 108

If you fail to drive your truck in line with Road Rule 108, various penalties could apply in South Australia. You can sometimes pay an expiation fee of $348, which means you can avoid prosecution. Alternatively, you may receive three demerit points, which will stay on your license record for up to three years. If you build up 12 or more demerit points, you may lose your license for at least three months.

Road Rule 108 aims to make sure truck drivers safely descend steep hills. All truck drivers must carefully follow this law while driving in South Australia. 

Click for more information on rules and regulations of driving a heavy vehicle or for information on heavy vehicle licence training.