Driver Knowledge Tests

Driving safely in rough conditions

Australia has some of the most diverse and punishing landscapes in the world, particularly in the outback. Searing heat, high humidity, corrugated roads, potholes, cattle grids, large road kill and torrential rain can occur within 100km on the same road!

So let’s look at what you should be aware of when driving in these conditions, and when your car is subjected to generally harsh driving.

Deep water

Particularly if you are venturing up into Queensland you’ll find markers on the side of the road that indicate water depth. Queensland gets flash floods regularly. Also, you’ll see numerous dry creek beds in the summer that can quickly turn into raging torrents of water that cross the road.

You’ll need to be extremely careful crossing these because you don’t want to get swept away. If it is safe to cross, bear in mind that the water may be up to your axles and this means that your brake disks are getting wet. When the brake disks are wet there’s a lot less friction for braking.

If you have driven through deep water you’ll need to dry your brakes afterwards and this is done simply by braking at a low speed. The pressure of the brake callipers will spread the water thin and the heat generated by the friction of the brakes working will evaporate the water.

Stock grids and cattle grids

Designed to stop stock wandering, a stock grid or cattle grid is a series of metal bars that stock can’t cross because their hooves fall in the gaps. Grids come in different varieties and ones used on main roads are more robust than ones used on farms.

However, as they’re metal and have gaps it means that your tyres don’t have as much grip. Metal is much more slippery in the wet, and they are much more likely to attract frost. Braking heavily on a cattle grid may cause a skid.

Driving downhill for a long distance

If you are using the brakes heavily for a long period of time, such as down the side of a mountain, your brakes will get extremely hot. Some brakes are better at coping with the heat than others, for example, if you have ventilated brake disks. If you are towing a trailer the stress on the brakes will be even more intense. Eventually you will boil the brake fluid if you are not careful.

Trucks can use engine compression braking, and cars can change down a gear to achieve the same effect. If your car is a manual, simply change down. If it’s an automatic you might have a sequential gear change option, or you might have L, 2, 3, D, in which case take it out of D and put it in 3 or 2.

If you overheat your brake fluid you’ll feel the pedal will go spongy and eventually will go right to the bottom without giving you any braking at all. This can happen extremely quickly. If you do get brake fade, put it in as low a gear as possible without over-revving the engine, try gently applying the handbrake (harsh handbrake use could cause you to spin out), and start looking for exit opportunities.

If you are on a steep hill you need to act fast because you will pick up speed quickly. If there is any way of turning so you are driving uphill, do it. You will need to scrub off speed as quickly as possible because if you go too fast you’ll end up slamming into another motorist head on, ramming another motorist from behind which might push them off the road or going off the side of the hill.

Other techniques will cause some damage to your car, but that’s preferable than writing it off or injuring someone. A hedgerow can be used to help slow you down as it will provide friction against your car. Small shrubs and bushes will also help as will fences and stone walls (though, be careful that you don’t flip your vehicle). Trees are a last resort because they will stop you very quickly.

If you are towing a trailer, beware of jackknifing (where the trailer pushes the back of your vehicle around).

When you do manage to stop, your brakes will be so hot that if you leave them on you will probably warp your brake disks. You should also consider changing your brake fluid once you’ve boiled it. Older brake fluid is less efficient than new brake fluid because it absorbs water. If you are likely to be driving in hilly regions frequently consider getting better brake fluid with a higher boiling point.


Mud can be on the road through landslides, earthworks and livestock movements. It is reasonably grippy if it is dry, but once it gets wet it is extremely slippery.

If you have been driving off-road, mud cakes in the tread in your tyres will reduce the grip you have, particularly in the wet until the mud disappears (which will be fairly quickly). This is because tyre treads are designed to disperse water so that more of the tyre is in contact with the road. Without these grooves the tyre can ride up on top of the water causing aquaplaning.

Gravel, sharp objects and road debris

Sharp stones are often present around road works, and in rural areas you will find gravel roads frequently. Road works will be signposted, as will similar hazards, and you can check out traffic sign quizzes here.

If you’ve driven on gravel it’s good practice to have a look around your tyres after you’ve stopped. Pop out any stones trapped in your tyre treads with a screwdriver as they can work their way through the tyre and cause you a puncture.

In the wet, tyres will more easily pick up shards of glass which can work their way into the tyre, too. Nails and other road debris will puncture your tyre more easily when slightly lubricated by water.

In cyclones and strong winds you will find a lot of branches and other debris on the roads. Smaller twigs tend not to be a concern, but a large branch can puncture or dent your petrol tank if you run over it.

You can often tell if you’ve picked up a slow puncture because you’ll hear a pulse in the road noise and you will start to notice your steering feels different.

Salt, sand and road works

If you live in an area where roads might be gritted or salted due to ice, for example the Snowy Mountains, this will cause rust on your vehicle if you don’t wash it off. We have an upcoming article on driving in the snow.

If you drive your vehicle on sand, sand gets everywhere. It’s extremely abrasive and will reduce the life of the moving parts in your car. Try to keep your car as clean as possible.

Animals in the road

If it’s a small animal or bird in the road it is safer for you to hit it rather than swerve and risk leaving the road or hitting another vehicle head-on. If it’s a large animal like a kangaroo or cow your options are not so good. Brake as hard as you can in a straight line, hold the horn down, look for potential exits. If you can see a safe exit, turn at the last minute – the animal may move before you need to do this. Even though it will cause damage to your car, it is usually safer to stay on the road and hit the animal than try to swerve off-road where there might be a hidden drop or something much more immovable than an animal (like a concrete culvert).

The exception to this would be if you are on a motorbike. You want to avoid hitting small animals as well as large animals because the likelihood you will come off the bike is quite high. If you hit a large animal it will send you over the handlebars. If you drop the bike you risk taking the animals legs out from under it and it landing on top of you. If you look for an exit it’s likely to be off-road and not ideal either.

In a truck, you can usually choose because you may have roo bars, and you are usually sitting high enough up that hitting a large animal won’t cause it to come through the windscreen like it can on a car.

Whenever you encounter new situations on the road try to anticipate whether this will affect how your vehicle handles and whether it could cause any damage.

Darren is an expert on driving and transport, and is a member of the Institute of Advanced Motorists

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Posted in Advice, Car, Heavy Vehicle, Motorbike