Driving in heavy rain and flood water - the top tips
British weather can be hard to predict at the best of times, and with severe weather becoming more the norm recently, it’s best to get clued up on the best way to drive in heavy rain and flood water so you can cope with whatever the weather throws at you.
Before you get in the car
Is the journey really necessary?
With the weather getting worse into the winter, you may have to have a serious think about your journey. You could get yourself into a lot of sticky situations when you travel needlessly.
- Make sure you check the weather, and more importantly if it is going to get any worse
- Check to see if any floods have been reported
- Check to see if your route is still accessible
- Have plenty of charge on your phone
- Ensure your tyres have plenty of tread and your lights are all working
Driving in heavy rain
Think about the space you are leaving between you and the car in front. Your stopping distance is going to double in the rain! Therefore, the 2-second rule becomes the 4-second rule.
With that in mind, ensure that you slow down. Just because the speed limit says 60, it doesn’t mean that it is safe to travel that fast in torrential weather conditions.
Stick your headlights on, and possibly even your fog lights too if visibility is less than 100m. This is so other road users can see you better and you can see them too!
Some things to be aware of
If you hit a patch of standing water (some of us might call it a big puddle) you might aquaplane.
Aquaplaning happens when a layer of water builds up between your tyres and the road which will cause you to completely lose traction.
As a result, you might:
- Have a louder engine due to increased revs
- Suddenly slow down
- “Light” steering
- Start “fishtailing” – this is when the back of the car swings out of line
How to control your vehicle when aquaplaning
- Keep calm
- Ease off the accelerator
- Keep hold of your steering wheel and keep it straight – it will require some effort
- Try and avoid braking
- If you have to brake, do it in small pumps
Otherwise, wait for the car to regain traction on the road and you will be able to brake normally and slow down.
Breaking down in heavy rain
If the weather outside is like a monsoon, do yourself a favour and keep the bonnet closed. Water can cause serious problems under the bonnet – in fact, the AA says that just an eggcup worth of water can wreck a combustion engine, and the electrics won’t thank you either.
Driving in floods
The best way to avoid getting into trouble when driving through a flood is to avoid it completely. It may add an extra few minutes to your journey, but with high flood water, you’re likely to get stranded and damage your car - so what would you rather do?
But, if there is no other choice:
Check out the situation first
Test the height of the water. In fact, you don’t even need to get your feet wet – a big stick will do the trick. WhatCar says that 10cm is the maximum depth of standing water that you should try and drive through.
The AA says that just 60cm of standing water is enough to make your car float. Admittedly, this is more relevant to newer cars with better door seals, but it can happen to any vehicle.
What might be a little scarier to hear is that just if half that amount (30cm) of water is moving, it can move your car, so don’t take the situation lightly!
Beware of the camber
A lot of roads are built with a camber. Therefore, you may experience deeper water near the kerb and the edge of the road. Be mindful of this before you attempt to drive through so you can keep to the middle where the shallowest part of the flood water is.
If you’re attempting to drive through standing water, or shallower water that is moving, then make sure no other vehicle is trying to manoeuvre through at the same time.Always let approaching vehicles make their way through first.
The key to driving through water is to go slowly and take your time. First gear should be plenty as you’ll need to keep your revs high. This goes hand in hand with ensuring you don’t stop. Both of these things will ensure you don’t get water into your exhaust pipe, which can cause incredible damage to the car and your wallet.
Try and strike a balance between going slow enough to keep control of the vehicle and fast enough to ensure your engine doesn’t get flooded. This is about 3-4mph. Any faster and you also may be at risk of aquaplaning.
When you get out of the flood water safely, make sure you gently press your brakes a few times to dry them off and make sure they are working as they should.
What to watch out for
- Other drivers may not be as careful as you, so always be wary about what they may do
- Manhole covers could get lifted and shifted underwater, so proceed with caution
- Floodwater is a known carrier of bacteria, so it’s always best to avoid it – just for your health! (If you’re thirsty you should probably wait until the next service station.)
- Water levels can change – quickly. It’s always best to avoid any sort of flood, especially if it’s moving
- Keep an eye on your tyres – tyres in good condition can dramatically reduce the risk of accidents in wet weather