Driving through a flood: how to drive safely in heavy rain, high winds and storms
Simple steps to stay safe on the road during thunderstorms and other bad weather
With heavy rain affecting many parts of the UK and causing serious flooding in some areas drivers are facing tricky conditions on the roads.
Rain, flooding and storms bring slippery road surfaces, puddles, hidden hazards and reduced visibility, so it’s important to know how to stay in control and stay safe on the road.
How to drive through flood water
Storms inevitably bring flooding and large patches of standing water which can catch out careless drivers.
Be wary of puddles and standing water. What might look like a minor puddle at the side of the road could be hiding a deep pothole or dislodged drain cover that could cause serious damage to your car. Driving through even fairly shallow puddles could also cause aquaplaning.
If you come across a seriously flooded road the best advice is to try to find an alternative route. A detour is better than risking your safety or damaging your car.
If you have to drive through a flood, first check how deep the water is. Get out and check, preferably using a stick to gauge the depth. Remember as little as six inches of flowing water could knock you off your feet, so take care. According to the AA, just a foot of moving water will float a car and two feet of standing water is enough to do the same. It recommends that you shouldn’t try driving through anything more than four inches deep.
If you’ve determined it’s safe to proceed, take it slowly and stick to the centre of the road. The crown, as it’s known, is the highest point so should be the shallowest section of the flood.
Don’t stop. Maintain a steady slow speed (3-4mph) and don’t change gear. If you need to, slip the clutch to keep revs up and speed down. In an automatic try braking gently while maintaining pressure on the accelerator. Moving slowly will help create a small bow wave which will stop the engine bay flooding. Stopping could flood the engine bay or could allow water to flow into the exhaust pipe - both of which are bad news.
Be aware of other vehicles and pedestrians. You don’t want to soak pedestrians or potentially flood or damage anyone else’s car.
If you do get stuck, it’s usually safest to remain in the car and call for help. Obviously, you need to use your common sense as to whether this is the best option depending on your circumstances.
Once you’re clear of the flood, dry your brakes. Apply them gently while driving slowly to remove the water from them.
Remember, modern cars are full of complex electrical systems which are vulnerable to water damage. Rushing through a puddle that forces water into the engine bay or wading into a deep flood could quickly cause expensive damage. Every year the AA rescues almost 9,000 vehicles that have driven through or become stuck in flood water, with an estimated insurance bill of more than £34 million.
How to drive in a thunderstorm
If you’re in the middle of a full-blown storm the simplest piece of advice is to avoid travelling if you can. Of course, that’s not always possible so if you must travel during a storm give yourself more time to complete your journey and be prepared to pull over and stop if things get particularly bad.
If you can, choose more sheltered roads and try to avoid routes you know are vulnerable to flooding.
Go slowly, put on your lights and increase your distance to other vehicles. Heavy rain or hail will affect your view of the road ahead so you’ll need more time to react. Wet roads also increase cars’ braking distance significantly and puddles create the risk of aquaplaning - when all four wheels lose contact with the road surface and leave you with no control of the vehicle. Reducing your speed can help cut the chance of this happening.
High winds can also make keeping control difficult, battering the car’s sides and even getting underneath and affecting handling and braking. Keep a firm grip on the wheel with both hands and be prepared for sudden gusts affecting the car.
Give vulnerable road users such as cyclists, motorcyclists and pedestrians more space - they’re more likely to be knocked about by high winds or affected by puddles.
Am I safe from lightning in my car?
In most cases, your car will protect you from lightning.
The Met Office advises that you close all the windows and stay inside your car. If lightning does hit your car the metal bodywork should act as a Faraday carriage, directing the current around the outside of the vehicle and into the ground rather than allowing it to reach passengers inside.
However, the Met Office also warns that convertibles with fabric roofs could be at risk of catching fire if struck directly, and that a lightning strike can still send a current through internal electronics and internal metal components such as metal door handles or pedals.