Human behaviour research -
Volvo Cars addresses the safety challenges for the aging population
Two car drivers approach the same intersection.
The 40-year old moves head and eyes rapidly, looking for potential dangers.
The 80-year old positions the car carefully, but the stiffer neck and narrower field of view make this routine situation more challenging than for the younger driver.
One of Volvo Cars' important safety targets is to design new technology that helps the growing number of elderly drivers to continue to drive safely.
We all are getting older. Demographic studies both in Europe and by the United Nations clearly show that the age pattern of the world population is changing. The elderly of today live longer and are also more active and healthier than before. This creates a higher demand for individual mobility than seen in previous generations.
"Understanding the driver's safety needs in the different stages of life is essential for us when designing our cars. Knowing what makes it easier for elderly drivers to handle the challenges that come with age is a very important part of that. Knowledge and research is the key here," says Thomas Broberg, Senior Safety Advisor at Volvo Cars. He adds:
"Accident statistics show that older drivers are underrepresented in crash involvement as a whole. However, this is not true in some traffic scenarios. Intersection and turning manoeuvres are overrepresented accident types when it comes to older drivers."
The question if elderly people are more dangerous drivers is a very sensitive topic in traffic discussions. Volvo Cars approaches the issue from another, more constructive angle.
"We know that there are traffic situations where elderly drivers have a different behaviour. We are building up the knowledge it takes to design safety systems that can help make these situations safer," says Thomas Broberg.
Volvo Cars conducts a lot of research on human behaviour in modern traffic. The aim is to gain more knowledge about how people handle and react in complex traffic situations.
Studying behaviour in intersections
Thomas Broberg has worked in a joint research project at the Swedish National Road and Transport Research Institute (VTI) in Linköping in order to see if there is a difference in older drivers' visual search behaviour at crossings.
"We wanted to evaluate to what degree the visual behaviour could explain older drivers' involvement in intersection accidents," says Thomas Broberg.
Two groups of subjects were selected through advertisement in the local newspaper and through registrations in subjects' database at VTI's website. Half of the chosen drivers in the study were over 75 years old and the other half were between 35 and 55 years old. Both groups drove the same test route, including different speed limits and a variety of situations: T-crossings, stop signs at two-road intersections, four-way crossings with traffic lights and roundabouts.
Apart from the driving test, neck flexibility was measured and a Useful Field Of View test (UFOV) was performed.
Differences base for development
Thomas Broberg summarises the results:
"The results from the UFOV test and the neck flexibility measurement showed a clear age difference. The older group had less flexible necks and narrower fields of view."
"During the driving test, our monitoring equipment picked up differences in the area of interest the drivers looked at. While the older drivers looked more at lines and markings on the road in order to position themselves in the traffic, the younger drivers focused more on dynamic objects such as other cars representing a possible threat."
Volvo Cars will use the findings as a base for refining the development of new preventive safety and support systems.
"We prioritise the issues that are the most common and dangerous in real-life traffic. Focusing on intersections is a logical next step since this research shows that older drivers would benefit from support in these situations. The positive spin-off effect is that safety systems that takes care of the special needs of older drivers' also will be useful for younger drivers," concludes Thomas Broberg.