See all Motoring AdviceWe all know that driving in the rain has inherent dangers which aren’t present when the roads are dry, but what do you do when a downpour becomes truly biblical, with flooded roads, lots of standing water and difficult driving conditions?
Slow down, leave extra space
We start with the obvious, but you’d be surprised how many people don’t adhere to these general rules. Wet road surfaces increase your stopping distances – how long and far it takes the car to come to a complete halt from a certain speed at maximum braking power – and this applies even if the roads are covered in a light film of rainfall. However, if they’re utterly drenched and littered with standing water, your stopping distances will be hugely increased. This means you need to leave extra room to vehicles in front of you (so no tailgating – in fact, hang back a long way and do the exact opposite), while you’d be advised driving at a lower speed than whatever the legal limit you’re in is saying at that point. This is particularly true on motorways, because 120km/h is highly inadvisable in driving rain with limited visibility and a soaking wet road surface; even 100km/h is probably too much in such instances.
Lights on, but not fog lights
The skies might be quite bright, even when it’s tipping it down, but have your lights on – it will make your car so much more visible in the spray being thrown up by other road users. If your car has automatic headlights, they won’t always turn on in rain; some of the more modern systems do, and there are even cars which have a dedicated light switch for poor weather, marked up with little graphics accordingly. But there are plenty of cars which won’t do the headlights themselves in the rain, so you need to get them onto dipped beam ASAP. Oh, and don’t put your rear fog lights on in heavy rain – they generate dazzle for other road users behind and they can also mask your brake lights, meaning someone could plough into the back of you. Fog lights are for thick fog, not rain – the clue is in the name.
Wipers on full
Again, a little like automatic lights, cars fitted with automatic wipers don’t always have the best sensors for deluge-like downpours. This can mean they’re only wiping at a standard speed, even if your windscreen is covered in rainwater. You’re best off adjusting the sensitivity of the wipers to their maximum, at the very least, but to be on the safe side you want to manually switch the wipers to their fastest setting – it’s the only way to keep your crucial forward visibility clear even in the heaviest showers. Additionally, if your car is fitted with a rear-windscreen wiper, you should have that switched on to its maximum setting too, as you can then keep a better eye on following traffic.
Run the air conditioning
If you have climate control or even manual air conditioning in your car, use it all the time in poor weather. When it’s raining the hardest outside, it’s the most likely time for the inside of the car’s windows to steam up, especially if you’ve had to run through the rain to get into the vehicle and your clothes/coat/umbrella etc are now wet through and drip-drying in the passenger compartment with you. Air conditioning is better at demisting the cabin than simply unconditioned cold or warm air from the ventilation system, and if you’re peering out of a tiny circle of cleared windscreen while driving in torrential rain, it’s a version of ‘portholing’ – driving along with limited visibility out of the windows of the car. It’s more common in winter months with frozen-up vehicles, but it counts just as much in a steamed-up car driving along in heavy rain and you shouldn’t do it as it provides a big safety risk if you fail to spot other road users (especially cyclists) through misted-up glass.
Avoid standing water – safely
It might be tempting and fun to splash your car through big puddles, like an overgrown child in wellies on a wet day, but it’s not advisable to do as such. First, if you’re in a built-up area and there are puddles near pavements, you could end up splashing a pedestrian. This is an offence and the gardai can prosecute you if it was proven to be a deliberate action. Secondly, you don’t know what’s under the standing water – there could be a massive pothole, for instance, which has allowed the puddle to accumulate in the first place, and if you go through that then you could damage your wheels or even your suspension, and that will prove costly. Third, if the water is deep enough and the car you are driving is an internal-combustion model with a low-mounted air intake, the water could get into your engine and ruin it at enormous expense; the car could even be a write-off in this instance.
And finally, you run the risk of aquaplaning if you’re travelling at enough speed, which is where the tyres lift off the road surface due to a coating of water. If this happens, your car is essentially totally out of control, as you have no grip on the road any longer and no way of altering your trajectory; in such instances, as soon as you feel the steering wheel go ‘light’ then you must release the accelerator gently, but do NOT use the brakes, and steer as straight as you can until the car has found grip again. All told, it’s best to avoid standing water, although obviously be safe – if you’re on a two-lane road and going round a puddle would otherwise mean a head-on collision with another vehicle, you’ll have to choose the lesser of two evils and either go through the standing water, slowly, or even come to a complete stop (if safe to do so) and wait for traffic on the other carriageway to clear before going around your watery obstacle. This links into…
Drive smoothly
Like driving on ice, when you’re in your car in heavy rain, grip levels are massively reduced. This increases stopping distances, as we’ve already said, but it also means you should drive like you would on snow and ice. So, employ careful, smooth inputs for the throttle, brakes and steering – no sudden, jerky movements of the wheel, for instance, or flattening the accelerator out of junctions. If the car starts to slide or wheelspin in very wet road conditions, you’ve got precious little chance of recovering it on sopping-wet tarmac.