Here's how to stay safe on the roads in bad weather

Monday, 31 May 2021

A few simple safety suggestions for safer driving in wet weather.

Driving can be dangerous even in ideal conditions, but the potential for trouble is so much higher when wet weather closes in - especially at this time of year, when seasons have shifted and dramatic changes in driving conditions can take us by surprise.

With the heavy rain and flooding currently battering the South Island and warnings in place for other parts of the country here’s a timely reminder of how to stay safer driving in bad weather. When there's water everywhere the world can seems dangerously surreal from the driver's seat. Heavy rain will affect your visibility, so the best advice here is to take it slow. If the rain is too heavy, then pull over in a safe place and wait for it to ease off.

Should you turn your headlights on?

If you need your wipers on, you need your headlights on.

Automatic light settings will not always activate in bad weather conditions, so it is up to you to make a sensible decision as to whether these need to be turned on.

Don’t rely on DRLs – the more visible you are in the rain, the safer you are.

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* Canterbury flooding: What you need to know

Drive your car like it is handling about half as well as it usually does in the dry.

“But,” you cry “My modern car has daytime running lights that are always on, surely this is good enough?

Daytime running lights aren't there to provide any extra visibility for you - their sole function is to make your vehicle more visible to other road users during the day. Just like you wouldn’t rely on your DRLs for your night vision, or to make your car visible at night, you shouldn’t just rely on them in bad weather either.

A good general rule of thumb is: if you need windscreen wipers, then you need your headlights.

Driving and corners

On wet roads, everything about the way your car handles is compromised. You probably have a decent idea of how well your car steers and responds, but if it's really wet, assume it'll only be half as good.

Always watch for other traffic and drive like they are about to do something stupid, because they could be.

On wet roads, your car's handling is compromised, even if you have a brand new car with all the latest driver assists. Be super-smooth and pretend the car is not its usual alert self. Because in tricky conditions, it's not.

If you've got a newer car it will have anti-lock braking, but if you have an older car, it might not. Either way, make sure you know.

Trucks can throw up a lot of water when they pass by – be prepared.

In an emergency situation where you must stop as quickly as possible on a wet road, you have to know what to do. In an anti-lock-equipped car, you'll need to brake as hard as you can and keep the pressure on - the technology will take care of the rest.

In a car without this technology, pressing too hard will cause the brakes to lock up and you could lose control.

Ideally you need to use 'cadence' braking, where you take the brakes to the point of locking and then gently release, over and over again. That's quite hard to learn and very hard to apply in a panic stop… so be even more careful when driving an older car in the wet.

Other road users

Keep it slow and steady through deeper standing water, never stop and don’t even attempt it if you aren’t completely sure.

Another simple rule should be applied here: never trust the other guy.

We all know people are unpredictable creatures and when on the road in bad weather you are definitely safest to assume that they are all idiots as well. So always be prepared for them to do something stupid.

We all know the two-second rule: count 'one thousand and one, one thousand and two' as the car in front passes a static object and if you pass it before you've finished counting, you're too close. But in difficult driving conditions, you should actually apply the four-second rule to account not only for reduced visibility and increased stopping distances, but also for the car in front to do something unpredictable.

You should also pay attention to oncoming traffic and keep a look-out for traffic moving at speed towards you on the other side of the road - especially trucks.

As they come past they can spray a huge amount of water straight onto your windscreen, and it can take a few moments for vision to clear. If you think that might be about to happen, reduce speed (don't brake suddenly though) and watch the direction of the road carefully.

And while cruise control is brilliant on long trips or for keeping your speed down in town, even the most advanced systems can't see potential drama unfolding ahead if someone else does something wrong, or even a massive puddle in the road. If you're not paying full attention because you've got the cruise on, you might not be able to react to a hazard in time. You are actually better off not using it in really wet conditions.

Aquaplaning and flooding

If water is standing in puddles on the road surface, your car is at risk of aquaplaning, which is when a wedge of water forms in front of the car’s tyre and lifts it up off the road surface, causing the tyres to lose contact with the road because the tread can’t displace the amount of water present.

To recover from aquaplaning, ease gently off your accelerator, have a firm grip of the steering wheel and be sure not to make any sudden steering actions. The car will eventually regain its grip as the water clears.

If you come across flooding, whether from the sheer volume of rain or something like a burst water main, then, obviously, slowing down is the first and foremost thing to do.

If you are familiar with the road, you can judge the flood in relation to the kerb to assess how deep it is. But remember to consider what impact the flooding may have had on the road underneath. The standing water may look like a normal flood, but the road surface beneath the water may be completely broken up.

If you have taken everything into consideration and decide to drive through standing (don’t even try if its moving) water, be sure to do so slowly. Drive as if you are doing a hill start, keeping the engine revs ticking over. This will prevent water from entering your exhaust. If you are in an automatic car, accelerate slightly but control the speed with your brakes.

When you have passed the flood, test your brakes to make sure they are dry and working properly, and remember to stay alert and avoid splashing pedestrians. That's only funny in television and movies.

Make sure you belong to a breakdown service

Cars are susceptible to breakdowns in wet weather, as electrics get wet and sometimes fail. It's dangerous to be stuck at the roadside in heavy rain, so make sure you have ready access to a breakdown service and a charged-up mobile phone, so you can get help quickly.

If you have broken down, don't leave the bonnet up. That'll just let more water into the works.