Not using a rear seat belt not only puts your life at risk, but means you could end up killing someone else

Spokesman, Rospa

In the UK it has been compulsory for adults and children to wear rear seat belts since 1991 and a series of shocking advertising campaigns have boosted compliance, but four in ten passengers still fail to use them.

In one of the first studies of its kind, Japanese researchers have attempted to find out the risk faced by drivers and front seat passengers when their back seat companions do not wear seat belts.

They found that in Japan, where rear seat belt use is not currently compulsory, 80% of deaths of front seat occupants could have been avoided if everyone buckled up in the back.

This amounted to an estimated 742 preventable deaths, and 1,520 severe injuries.

Risk

The risk of death to front seat occupants was multiplied by five, they found, if they were accompanied by an unrestrained back seat passenger.

The researchers wrote: "Our findings show that seatbelt use by rear seat occupants of cars is associated with less injury and death of front-seat occupants

"Most deaths and severe injuries of front-seat occupants of cars would potentially be averted by rear seatbelt use."

A spokesman for the Royal Society for the Prevention of Accidents (Rospa) said that car manufacturers should aim to design easy-to-use rear seatbelts.

People in this country tend to look after their children in this regard, but not themselves

Rospa

He said: "There may be differences in rear-seat belt use between the UK and Japan, but the impact on people in the front seat during an accident is the same.

"People in this country tend to look after their children in this regard, but not themselves.

"Not using a rear seat belt not only puts your life at risk, but means you could end up killing someone else."

The Department of the Environment, Transport and the Regions (DETR) estimates that rear seat belt use saves 140 lives a year.

It says that 40 front seat passengers die each year as a result of rear seat passengers not wearing them.

Their most recent figures suggest that 56% of adults, and 90% of children, wear a seat belt while sitting in the rear of a car.