Essential Checks Before a Long Motorway Journey

Start With the Tyres — They Do the Hardest Work

At 70mph on a motorway, each of your tyres is doing a job that no other component has to match. It is the only thing between you and the road surface, and it is also the easiest thing on the car to check. Do it before you load up, when the tyres are cold and the car has been sitting for at least an hour.

Find the correct pressures in your handbook or on the sticker inside the driver's door pillar. Those figures are usually quoted in psi or bar, and 1 bar is roughly 14.5 psi, so don't mix them up. If you are carrying a full boot and four passengers, use the "laden" pressures rather than the solo-driver ones — many cars list two sets.

• Pressure: check all four, plus the spare if you have one. A tyre can lose a few psi a month without looking flat.
• Tread: the legal minimum in the UK is 1.6mm across the central three-quarters of the tread, around the whole circumference. For a long motorway run, 3mm or more is a far safer place to be, especially in standing water.
• Condition: run your hand around each tyre and look for cuts, bulges, or screws and nails embedded in the tread. A bulge in the sidewall means the tyre needs replacing, not repairing.

Under-inflated tyres overheat, wear faster and burn more fuel. If one tyre keeps losing pressure, get it looked at before you go rather than topping it up and hoping.

Under the Bonnet: Oil, Coolant and Screenwash

Give the engine a few minutes to settle, park on level ground, and work through the fluids. This takes ten minutes and can prevent the kind of breakdown that leaves you stranded on the hard shoulder.

Engine oil. Pull the dipstick, wipe it, push it back in, then pull it out again and read the level. It should sit between the minimum and maximum marks — nearer the top if the car is older or does longer journeys. Top up with the grade specified in your handbook, a little at a time, checking as you go. Running low on oil at motorway speeds can destroy an engine in minutes.

Coolant. Only ever check the header tank when the engine is cold; opening a hot cooling system can spray scalding water. The level should be between the min and max marks. Top up with the correct mix of antifreeze and water, not neat water, which dilutes the protection. While you are there, glance at the hoses for cracks or crusty white deposits that hint at a leak.

Screenwash. Fill it properly. Motorway driving throws up far more spray, grit and insects than town driving, and a weak mix will freeze in a cold snap or smear across the glass. Keep a spare bottle in the boot.

Lights, Wipers and Visibility

You cannot check brake lights on your own, so ask someone to stand behind the car while you press the pedal, or reverse up to a window and use the reflection. Work through everything: headlights on dipped and main beam, indicators, fog lights if fitted, and the number plate lights.

Replace any blown bulbs before you set off. It is a legal requirement to have working lights, and a failed brake light on a motorway is genuinely dangerous. If your car uses LED units, a fault usually shows as a warning on the dash rather than a simple bulb swap.

Look at your wiper blades too. If they are leaving streaks, juddering, or the rubber is split, new blades are cheap and take a couple of minutes to fit. Check the washer jets actually hit the screen rather than the roof, and clear them with a pin if they are blocked.

Brakes, Battery and the Small Things

Brakes get hot and heavily used on a long run, particularly if you are laden or towing. If the pedal feels spongy, the car pulls to one side under braking, or you hear grinding, get it checked before your trip. Brake fluid absorbs moisture over time and is normally replaced every two years, so check when yours was last done.

Batteries fail quietly and often at the worst moment. Look at the terminals for white or green corrosion, make sure the battery is secure, and if the car has been slow to start lately, have it tested. A long motorway run will charge a healthy battery, but it will not rescue a dying one.

Other quick checks worth doing:

• Engine bay: make sure the bonnet closes and latches properly.
• Luggage: secure anything heavy, and keep the rear parcel shelf clear so your view is not blocked.
• Fuel or charge: plan your stops so you are not hunting for a filling station at the last minute.

Pack for the Journey, Not Just the Destination

A few items in the boot make a real difference if something goes wrong. Keep a tyre pressure gauge, a torch, a hi-vis vest for each occupant, a warning triangle, a warm blanket, bottled water, and a phone charger. A basic first aid kit and jump leads are worth the small amount of space they take up.

Check your breakdown cover is current and that it covers the vehicle you are driving, especially if you are using a courtesy car or a hired one. Save the number in your phone rather than relying on finding it at the roadside.

On the Day: A Two-Minute Walk-Round

Before you turn the key, walk around the car once. Check nothing is left on the roof, the tyres still look right, and no warning lights stay on after the engine starts. Set your mirrors and sat nav before you move, not at 60mph.

Once you are on the motorway, keep an eye on the temperature gauge and any warning lights during the first twenty miles. Plan a break every two hours — fatigue on a long motorway run is a bigger risk than most mechanical faults. Ten minutes of checks before you leave is the cheapest breakdown insurance you will ever buy.