Your tyres are the only contact point between your car and the road. On a long summer journey, they face the heat of the tarmac, the weight of luggage and passengers, and hours of sustained motorway driving. An under-inflated tyre heats abnormally and can blow out. A worn tyre will not drain water correctly when a summer storm hits. Both situations can be fatal.

Start with pressure. Check it cold, before driving, according to the values on the label inside your driver's door frame. For a long journey with a loaded car, increase the pressure slightly above standard values. The correct pressure is generally between 1.8 and 3 bar depending on your model. Do not forget the spare wheel or puncture repair kit.

Opening the bonnet is the check most drivers put off indefinitely. It is also the one that can save you from the most expensive problems. In the middle of summer, an engine running low on oil or coolant can fail within minutes in a motorway traffic jam. Replacing a seized engine costs thousands. Checking fluid levels takes five minutes.

Brakes are the most critical safety system in your car. On a long journey with a loaded vehicle, they are used more intensively than in normal use, particularly on mountain descents or in repeated slowdowns on busy motorways. If you hear squealing, feel vibration or notice the brake pedal sinking more than usual, get it checked before you depart.

Visibility is equally important. A summer storm can appear without warning. Wiper blades that streak or judder are ineffective in heavy rain. A windscreen with an unrepaired chip can crack under pressure and temperature changes on the motorway. Both are simple and quick to fix before departure.

The battery is a point most people overlook in summer, wrongly. In high heat, an ageing battery can weaken considerably. If your battery is more than three or four years old and you have not had any warning signs, a check at a garage or with a consumer battery tester can save you from a breakdown on a service station forecourt at 35 degrees.

Air conditioning is your best ally on a summer road trip. A failing air con system means an exhausting journey for everyone on board, and a genuine risk of drowsiness at the wheel. Test it before departure : on a warm day, the air should be properly cold within two minutes. If it is no longer producing intense cold, the refrigerant may need recharging.

In the UK, a warning triangle and a high-visibility jacket are strongly recommended and required in many European countries. If you are driving abroad this summer, check the specific requirements for every country you are entering. France, Spain, Germany and Austria all have mandatory equipment rules that differ from the UK. A fine at a border checkpoint is not the start to a holiday anyone wants.

Beyond the legal minimum, a few simple additions can turn an incident into a minor inconvenience : a puncture repair foam can get you to the next garage without needing a full tyre change, a basic first aid kit covers the immediate needs, and a jump-start cable or portable booster means a flat battery does not strand you. And enough water for all passengers, especially if you are travelling with children or elderly relatives on a hot day.

Preparation does not end when you pull out of the driveway. On the road, a few simple habits make the difference between an enjoyable journey and an exhausting one. The golden rule : take a break of at least 15 to 20 minutes every two hours, and at the first sign of tiredness. Drowsiness at the wheel is responsible for a third of fatal motorway accidents.

For electric and plug-in hybrid vehicles, plan your charging stops before you leave. Locate compatible chargers on your route using apps like Zap-Map or Chargemap, and never let the level drop below 20% in poorly equipped areas. In mountainous regions or in peak summer, queuing times at chargers can be significant. Apps like ABRP can plan the most efficient charging route automatically.

Programme your GPS before starting the engine and download an offline map if your route crosses areas with limited signal. Identify service stations on your route so you are never caught out by an empty tank in motorway congestion. And turn the air conditioning down to a moderate level : the difference between inside and outside temperature should stay between 5 and 7 degrees to avoid thermal shock every time someone gets in or out of the car.