Why fast roads are different
On a slow street, a stopped car is an obstacle. On a highway, it can be a serious hazard, because other vehicles approach at high speed and drivers may not expect a stationary object. The general principles of a car breakdown still apply, but the margin for error is smaller, and your own position matters more than the car.
While the car is still moving
At the first sign of trouble, such as a loss of power, a strong vibration or a sudden warning, stay calm and avoid sudden moves.
- Turn on the hazard lights right away.
- Ease off the accelerator rather than braking hard.
- Check mirrors and signal if you can, then move toward the right-hand shoulder in countries that drive on the right, or the left shoulder where traffic keeps left. Highways also sometimes have a median-side shoulder, which is usually the less safe option because it is narrower and more exposed to fast lanes.
- Use the momentum you have to reach the farthest point you can, such as an exit ramp, a service area or an emergency bay, rather than stopping at the first opening.
If the engine fails, the steering and brakes may feel heavier because power assistance can stop with the engine. Keep a firm grip and slow gradually. Do not try to restart the engine on the move.
Choosing where to stop
On a highway, you ideally want to stop:
- As far from the traffic lane as you can, with the wheels turned away from the road.
- On a straight section with good visibility behind you, not on a bend or just past a crest.
- Near an emergency phone, mile marker or exit, which helps responders find you.
If you must stop in a traffic lane because you cannot reach the shoulder, keep the hazard lights on and call emergency services. In that case, getting out may or may not be the safest choice; read the next section carefully.
Staying in or getting out
Advice differs depending on the situation, and local authorities may give guidance specific to your area.
Getting out is generally preferred when the car is on a shoulder, because a vehicle that is hit from behind can be pushed forward with great force. If you leave:
- Exit through the passenger-side door, away from traffic, and bring any passengers the same way.
- Take your phone, and your keys if you may need them.
- Move well away from the car and the road, typically behind a guardrail or barrier, or far up an embankment. Standing in the space directly behind or beside the car is generally the riskiest place.
- Keep children and pets with you and away from the road.
Staying in the car with the seat belt fastened is sometimes advised when you are stuck in a live lane with no safe place to walk, or when it is dark and visibility is poor. If you stay, keep the hazard lights on, lock the doors and call for help immediately. This is a judgment call, and both choices carry risk. Never stand in a live lane to flag down traffic.
Making the car easy to see
Visibility is your best protection. Keep the hazard lights running for as long as the battery allows. At night, an interior light and a bright vest or reflective clothing may help others see you if you are outside. If you carry a reflective triangle, only place it if you can do so without walking into traffic. Rules for warning devices vary, and some places discourage walking along a highway to place them.
Many people keep these items in an emergency kit, including a flashlight and a high-visibility vest, because they matter most in exactly this situation.
Calling for help
You can usually reach emergency services and roadside assistance from your phone. Be ready with:
- The road number and direction of travel.
- The nearest mile marker, exit number or landmark.
- Whether you are on the shoulder, in a lane or off the road.
- A description of the car, the number of people with you and any injuries.
- Any hazard such as smoke, fuel leaks or a damaged vehicle blocking a lane.
If your phone has no signal, an emergency roadside phone, where available, can connect you with the operator. Walking to find help is not generally recommended on a fast road. If you consider it, consult local guidance first and avoid doing so at night or in bad weather.
Tell any operator whether you need a tow. Highways often have designated towing arrangements, and unrequested tow operators can show up. Ask the dispatcher what to expect and check any vehicle that arrives matches what you were told. More on questions to ask can be found in the article on how towing works.
What if it is more than a breakdown
If a tire has failed at speed, the car may pull or vibrate. Hold the wheel firmly, ease off the accelerator and let the car slow before steering to the side. Changing a flat on a narrow highway shoulder is often not worth the risk, so waiting for assistance may be the better choice. A blown tire can also happen after a slow puncture goes unnoticed, which is another reason to check tire pressure before a long drive.
In a minor collision on a highway, moving vehicles out of lanes is often encouraged if they can be driven, but local rules differ. If someone is injured, do not move them unless there is immediate danger.
Before the next long drive
A little preparation reduces the odds of a highway breakdown. Keep up with regular servicing, check fluids, tires and the battery before a long trip, and make sure the fuel tank or battery has enough range for the next stop. Electric car drivers should plan public charging stops with a margin rather than aiming to arrive on the last few percent. Having a roadside assistance plan, a charged phone and a stocked kit is a sensible default.
Procedures and legal duties vary by location, so check the guidance from the highway authority or police where you drive.