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Six Driving Conditions (Road Conditions)

Most drivers criticise or lay blame for poor road conditions, however of the 100s or tens of 1000s of drivers each day who drive along particular parts of the road, on average 99.9% of them make it safely. If the roads are dangerous why doesn’t everyone crash?

ROAD

slippery road

The shape of the road, where is the edge of the road, negative & positive camber on corners, potholes, gravel roads, bull-dust, mud, ice and water. – What other words describe the roadways we drive on?

Conditions change from road to road – from a side street to a main road, from a back road to an expressway, and conditions on the same road change – with weather, traffic and construction.

Tyres have poor grip on wet/gravel roads as the road surfaces under the tyres is moving as the tyre travels over it. When you turn the wheels to drive around a bend, the vehicles momentum will try to keep the vehicle going straight ahead, with the front wheels having reduced effects.

Sealed country roads are narrower and have more curves/bends than city roads – even though the full speed limit applies. Many of the curves/bends have poor vision with bush close to the side of the road. This gives less warning of any wild life that may cross the road, vehicle broken down.

Road Edge. Another situation is where dirt has worn away from the edge of the bitumen. Because the roads are often too narrow for passing vehicles to both remain on the sealed road, one or both of the vehicles may place two of their vehicles wheels off the bitumen to allow safe passing.

When the opportunity comes to return on to the sealed portion, drivers can get into trouble if they do not know how to bring the vehicle back safely. When you return to the bitumen:

¨ Choose a place where the road shoulder is not washed away as bad or deep;

¨ Don’t `ease’ your vehicle back over the road shoulder – keep some power on and let the side   momentum help you get back to the bitumen.

A defensive driver recognizes the changing conditions and chooses to make the necessary allowances for them:

¨ Be alert to the shape, surface and shoulder of the road.

¨ Respond to the signs of potential hazards. Watch for wet roads gravel, sand, mud and water.

¨ Test road traction by lightly applying the brakes at slow speed to get the `feel’ of the road.

¨ Reduce speed under slippery conditions.

Driving in the country usually means longer driving hours where fatigue can set in. If you have been driving for a couple of hours at high speed with little to keep you alert, it is easy to approach some hazard such as a curve, narrow roads or causeway too fast with terrible results.

How is country driving different to driving in a metropolitan area? When driving in rural areas, road conditions can vary from bitumen surfaces to gravel and dirt. Be careful of potholes, soft and high road edges, narrow bridges and dusty roads. You should always be alert and keep an eye out for any dangerous situations. Drive at a speed that suits the conditions.

Australia has more than 800,000km of roads, of which 320,000km are sealed with bitumen or concrete and 313,000km are `improved surfaces’ usually of gravel, whilst the remainder are formed or cleared. That means more than 60% of Australia’s roads are gravel, sand or dirt.

Wet Road Conditions

At 100 kph on a wet road, an average tyre will have to displace up to

9 litres of water per second to maintain grip on the road surface.

Wet or snowy conditions. Rain, hail, sleet and snow make driving a vehicle a challenge and extra concentration is always needed. Even the lightest of  showers can make road conditions slippery, particularly when mixed with oil and other substances that have accumulated on the road way over time. Rain, hail, sleet and snow also affect visibility when driving and can result in additional hazards like localised flooding or debris on the roadway.

If you choose to drive too quickly through water on the road you risk the vehicle aquaplaning or sliding and becoming uncontrollable.

If water over the road is too deep for your vehicle, stop the vehicle in a safe area and check the depth before driving any further. If you have doubts about walking water—you have doubts on driving through water.

After driving through water, always check your brakes to be sure they are working effectively by driving for a short distance with your foot pressed gently on the brake.

Most importantly, as the coefficient of friction between the road surface and the tyre’s contact patch decreases,

the amount of cornering grip available decreases & braking distances increases.

Motorists driving in wet or snowy conditions should remember the following:

¨ Slow down in wet weather. The posted speed limits are the maximum speed with good conditions so if conditions are hazardous drivers should reduce their speed accordingly.

¨ Increase your braking distance and leave ample room between your vehicle and the vehicle in front of you.

¨ Turn on your headlights to increase visibility and ensure your windscreen wipers are working effectively.

¨ Make sure your tyres have ample tread and are inflated to the required level.

¨ Exercise patience. With wet weather there will inevitably be increased volume of traffic on the road due to those who generally walk or ride a bike using their vehicle instead.

¨ Apply your brakes in a steady and controlled manner. Braking hard and suddenly in wet weather can cause you to lose control.

¨ Do not accelerate quickly. Apply gentle pressure to your accelerator to avoid skidding.

¨ Allow extra time to travel to your destination.

¨ Unless you are fully aware of the water depth, flow and any road damage or impediment, do not attempt to cross a flooded road, bridge or causeway.

¨ If heavy rain, hail, sleet or snow make driving too difficult pull over safely to the side of the road and wait until conditions ease.

Crash-free Driving on Country Roads

The faster you chose to drive off road – the higher the risk of losing control of the vehicle.

It will not take much to lose control of your vehicle off road – and if you did – it can be very difficult to regain control.

Always be in the correct position, the correct gear and the correct speed.

Gravel Roads have all of the above circumstances but with the added difficulty of driving on an unstable surface. Because gravel moves under the tyres, a vehicle can drift sideways off the road. If this occurs on a corner, there is a high risk that the vehicle will rollover as the wheels leave the gravel and ‘bite’ into the soft shoulder.

 

Other hazards of gravel roads are corrugations across the road. This is where the road surface has a ripple effect similar to corrugated roofing iron. This effect causes the wheels to ‘chatter’ as they make a little contact with the road surface, bouncing along the top. Vehicles can easily drift sideways and off the road in these situations – even at low speed.

Reduce the risk of a vehicle incident on Gravel roads

¨ Slow down and reduce your speed to suit the conditions – there is less traction on gravel roads and it is easier to lose control, compared to driving on a bitumen surface.

¨ If traffic signs warn of a gravel road ahead, slow down while you are still on the bitumen.

¨ The transition of bitumen to gravel is often eroded and should be approached and departed with suspicion. Likewise, the approach to cattle grids can be seamless or severely rutted.

¨ Do your braking before you enter corners. Slow down enough so that you can exit the corner while applying gentle acceleration. This enables the suspension to remain loaded and drives the vehicle through the corner in a controlled manner.

¨ Follow tyre tracks wherever possible – this will provide firmer ground. Keep away from the loose gravel on the edge of the road, it could pull you off the road and may cause the vehicle to rollover.

¨ Slow down for corrugations (bumps on the road) – the old adage about speeding up to travel over the top may appear to work for small corrugations, but you could lose traction. When corrugations get severe you may lose control of the vehicle.

¨ Watch out for the slope or camber of the road on corners – it could be sloping in the wrong direction and cause you to skid off the road if you are travelling too fast.

¨ ABS will work differently on gravel and may increase your braking distance. If you have to brake heavily be aware of the difference in the braking sensation of ABS.

¨ Consider using a lower gear when driving. It will give you better control and enable you to use the engine as a brake rather than relying on the brakes.

¨ Try to steer and brake as smoothly as possible – jerky or sudden braking or steering will increase the risk of your vehicle skidding.

¨ Watch out for dust ahead. It could be a sign of an oncoming vehicle, or it could signify that you are coming up behind a vehicle – switch your headlights to low beam when driving in dust.

¨ Slow down and keep left on the approach to blind corners and crests – if you meet an oncoming vehicle it may be difficult to avoid a collision

¨ Don’t swerve to miss an animal, you may lose control of the vehicle and you can’t predict which way the animal will go. Slow down and stop, if necessary, until the road is clear.

Just because you own or drive a 4WD, does not automatically make someone a four-wheel driver.

 

Before driving on gravel roads or in remote areas, familiarize yourself with your vehicle and consider taking our 4-wheel driving course.

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