Almost a fifth (18%) of road users suffer nausea or sickness as a driver or passenger, a new survey suggests.
Sitting in the back seat of a car appears to be the worst place for motion sickness, with 75% of sufferers saying that is the main place they feel unwell.
The top reason people gave for feeling sick is reading in the car (61%), followed by using a tablet or phone (50%), winding country roads (37%) and a lack of fresh air (32%).
More than a third of drivers (37%) say they have had to take a break as a result of someone feeling unwell in their car, with 2% having to abandon journeys or avoid them altogether.
Nearly a quarter of drivers (24%) said they used to suffer from car sickness, but later grew out of the condition.
The RAC surveyed 1,990 UK drivers for the research.
Rod Dennis, a spokesman for the firm, said: “While car sickness is often associated with younger children, our research suggests it still remains a problem for a substantial number of older drivers and passengers.
“Even if a driver doesn’t suffer sickness themselves, they could suffer some unfortunate consequences if they cause any of their passengers to become unwell simply because they are accelerating or braking too sharply.”