What happens to your tyres when driving on wet roads

With the rainy season upon us once again, except if you live in the Western Cape, South African motorists must be prepared to drive on wet roads.

Driving on wet surfaces, under poor visibility, can lead to unsafe situations, which, coupled with poor vehicle and tyre conditions, increases the risk of danger on the roads.

When your tyre comes into contact with wet surfaces the small layer of water between the rubber and tarmac diminishes grip.

The tread of the tyre, referring to the pattern of bumps and grooves, is thus not only designed to maximise traction on dry roads but also to disperse water away from tyre if necessary.

If said tread has been worn down, the water cannot be diverted effectively. Therefore, the water rolls around the wheel, with no grip and traction to the surface, leaving you with loss of your vehicle’s steering control.

The legal limit for tyre tread in South Africa is 1.6mm, and motorists can look for a small rubber bump in between the grooves to determine how much health their tyres have left.

If it’s level with the rest of the running surface, well let’s just say, the tyre shop should be one of your next stops.

Weathering the storm

Local tyre manufacturer Dunlop has compiled several essential tips to help drivers navigate rainy conditions safely.

First and foremost, ensure your tyres are correctly inflated.

Apart from affecting fuel usage, over-inflated tyres mean there is “less” of your tyre that has actual contact with the road, reducing the surface area for grip and traction.

Also, ensure you have wiper blades that function effectively.

If your car generally sits in harsh conditions, such as direct sunlight, this could lead to blades warping, leading to ineffective water clearing from your windshield.

“Regularly inspect your wiper blades so that you’re able to effectively dispel water from your windshield, giving you better visibility,” said Dunlop.

It is furthermore important to understand your vehicle’s water-wading capabilities. Bigger vehicles like bakkies and SUVs generally have a higher tolerance level for water, as opposed to smaller passenger cars like hatchbacks and sedans.

Venturing into deep waters could therefore compromise the vehicle’s air intake system and cause unnecessary damages as well as create a dangerous situation, especially if the water is on the move.

Once on the road, it’s imperative to keep your wits about you as rain could turn a usually calm street into chaos.

If it’s raining before you head out, watch out for news alerts in your area to find out if your route is flooded.

Identify alternate routes, and factor in additional driving time for traffic, as well as for driving slower in inclement weather.

Say you were caught off guard and the road is flooded, proceed with extreme precaution and preempt the dangers you may encounter.

“For example, before attempting to drive through it, try to gauge if the water is shallow or deep, if it’s moving or stagnant, or if there are any obstacles or debris in the water,” said Dunlop.

When going through, ensure that you keep the vehicle in the centre of the road, which is the highest point.

Avoid aggressive acceleration or braking as this may cause your vehicle tyres to lose traction. As a safety precaution, once you have safely navigated the water tap your brakes lightly with the aim to dry and eradicate any water in the braking system, to ensure that your braking system works optimally.

“If the water is too deep, swift-moving, or you cannot see the road beneath it, it’s best to use an alternative route,” said the experts.

On a normal wet road that isn’t flooded, the risks are still numerous.

If your tyres have poor grip with the in wet conditions, the driver can lose control of the vehicle in what’s called aquaplaning, or hydroplaning.

This happens when the water sits between the car and the road, so there is nothing for the vehicle to grip on to, rendering the driver powerless to control the vehicle.

In this scenario, do not slam on the brakes. Instead, take your foot off the accelerator and let the car slow down. If you need to, and your vehicle is equipped with anti-lock brakes, you can lightly apply the brakes to help the tyre regain traction.

Hold the steering wheel steady, as moving it too much could cause your car to further lose traction and spin out of control.

Once back in control, continue with your travels or pull over safely on the side of the road to regain composure.

With potholes a regular challenge on roads, heavy rains may lead to the development of new potholes – sometimes overnight.

Water collects in them, and drivers may assume they are driving over water, when in fact, it’s a pothole. When hit, the sidewall of a tyre acts a shock absorber, but it can also lead to tyre damage.

Therefore, try to avoid driving in the outer lanes, as water tends to pool in there. Stick to the centre lanes where the road is less likely to be flooded.

The hands-down best way to keep yourself safe out on the wet streets is to be proactive.

Ensure you have a spare wheel that is in good shape should you need to replace it in the wild.

If you are using a biscuit wheel – these are the narrow tyres kept as spare tyres in some vehicle models – the narrow surface area does not offer great capacity to expel water. Drive more carefully, and avoid flooded roads.

Much like making a dental appointment should be a routine to keep your pearly whites healthy, so too should a tyre check-up be to ensure your tyres are in good health and able to withstand harsh conditions.

Lastly, always carry an emergency kit in your vehicle that includes essentials such as a spare tyre, jack, flashlight, blanket, and first-aid supplies. Additionally, ensure your mobile phone is fully charged in case you need to call for help.