Protecting people in cars: are we forgetting the back seat?

Current regulations do not require dummies to be placed in the rear seat during crash tests. AAP

Since the introduction of the seatbelt into motor vehicles over 40 years ago, there have been major gains in protection to occupants in automotive crashes. This progress has not been observed in the rear seat, however, and you are now safer in the front seat than the back during an accident, so what can be done to improve rear seat safety?

Worldwide over the past few decades there has been substantial investment in research into reducing injuries in motor vehicle accidents and policy development. Vehicle manufacturers responded with enhanced safety designs. The US Department of Transportation’s National Highway and Traffic Safety Administration (NHTSA) estimated that vehicle safety technologies saved 328,551 lives between 1960 and 2002.

In Australia, Victoria passed the first law of its kind in the world in 1970, making seat belt use compulsory for front seat occupants. The lap-only belt slowly evolved into the three-point lap-sash belt we know today. That evolution continues with the introduction of advanced seat belt technologies to front seats in some new vehicles that aim to reduce the belt forces on the body.

Front airbags have become common in cars, providing protection to the head and upper body, along with curtain airbags that deploy in a side impact aiming to prevent head and neck injuries.

This is in stark contrast to the rear seat where protection is often limited to the standard lap-sash belt, and sometimes a curtain airbag that is extended from the front seat into the rear. So, with all of this wonderful technology to save lives and reduce injury, why has the rear seat been left behind?

Historically, the driver and passenger have been the highest priority simply because those seats are occupied most often and therefore account for the greatest number of casualties. This has meant that the attention of both regulatory –such as Australian Design Rules (ADR) for vehicles - and consumer testing programs – such as the Australasian New Car Assessment Program - have focused on drivers and front seat passenger safety systems.

Child restraint systems, usually used in the rear seat, have also been the subject of mandatory performance standards and consumer testing, such as the Child Restraint Evaluation Program. These approaches have been highly successful in driving improvements in design of safety systems in the front seat and for child restraint users. But the rear seat has consistently received little regulatory, consumer or research attention.

The purpose of the Australasian New Car Assessment Program (ANCAP) is to provide consumers with “information on the level of safety provided by vehicles in the event of a serious accident.” Given this information is only applicable to front seat occupants, it is hard to see how it is giving an overall assessment of a vehicle’s safety.

It must be noted that there are child crash-test dummies representing an 18-month-old and three-year-old child placed in the rear seat of ANCAP tests. However, there are no performance requirements for these dummies and thus they do not affect the score given to the safety of the vehicle.

We must also consider that these child dummies only reflect a very small percentage of the occupants who sit in the rear seat, with North American data showing a wide distribution of rear seat occupant age, with approximately a third being 18 years or older.

Other consumer test programs around the world have also shown little interest in rear seat occupant protection, with the exception of Japanese and Chinese consumer test programs where a dummy representing a small female has recently been added to the rear seat. This is a direction that ANCAP, and other new car assessment programs, must seriously consider. It would make minimal difference to the cost of ANCAP tests, while providing additional information on vehicle safety performance to that currently being reported in most NCAPs.

Work conducted at Neuroscience Research Australia on US mass crash data has shown that while newer cars are safer than older cars, significant reductions in head, thoracic and abdominal injuries were only seen in front seat occupants, not rear seat occupants.

Front seat occupant protection has improved to the point where the front seat is safer than the rear seat for occupants over 15 years of age. The 9-15 age group are at a lower risk in the rear seat, but even the relative protection offered to these occupants has decreased over the last 10-15 years.

For younger occupants up to eight years old, our group at Neuroscience Research Australia has demonstrated that the highest priority for injury prevention is to encourage the correct use of size-appropriate child restraints in the rear seat. This research formed the basis for the new national legislation requiring the use of age-appropriate child restraints by all occupants up to seven years of age.

Similarly, we need to approach the problem of rear seat injuries and fatalities from both a regulatory and consumer testing viewpoint. Our research is starting to build an evidence base to convince ANCAP to place an adult crash test dummy into the rear seat of consumer tests. This will encourage vehicle manufacturers to place more emphasis on rear seat occupant protection.

There also needs to be an evidence base to justify regulatory change. Our research group is currently conducting an in-depth crash investigation study to determine how people get injured in the rear seat. This will guide our laboratory work in the evaluation of both existing and novel technologies to reduce injury.

We could save more lives and prevent more injuries if we paid the same attention to the rear seat as we do to the front seat. There is no need to reinvent the wheel to make a big impact here – simple countermeasures can be achieved through the use of existing technology by tailoring them to the occupants who sit in the rear seat. So let’s treat rear seat passengers as seriously as we have those in front.