Better car design for drivers of all ages

As the population ages, there will be more and more older drivers on the road. Sukru Karali and colleagues examine what the needs of olders drivers are and ask whether these needs are being met by current car design.

The population of older people around the world is increasing, particularly in developed countries. As a result, there is an increase in the number of older drivers. UK Government figures report that there are more than 15 million people aged over 60 with a driver’s licence. More interestingly, over a million of these drivers are over 80 and 124 are aged over 100.

Vehicle design and performance are constantly being developed, with vehicles becoming smarter and more sophisticated. Contemporary vehicles are now equipped with many characteristics formerly restricted to the luxury market. For example, at one time electric windows and power steering were only available in high specification cars but are now considered standard. Today, technologies to assist the user with specific driving tasks, such as intelligent automated parking systems, are becoming more common.

Previous research has shown that most vehicles are designed to meet the needs of the majority of the able-bodied male population, but the automotive industry has not fully addressed the needs and expectations of the whole population, including people with age-related disabilities.

A questionnaire survey was conducted by researchers at the Design School at Loughborough University to understand the experiences of car drivers of different ages and to identify some of the key challenges for car design. This survey was the first phase of a three-year research project. The project focuses on vehicle ergonomics and inclusive design in order to explore design solutions to age-related challenges and to make design recommendations for the automotive industry.

Major organisations within the UK were consulted and agreement was obtained for distribution of the questionnaire to the target audience. These were well known institutes, voluntary action groups, charity and motoring organisations.

Interviews were also conducted with 15 drivers aged 65 years and over. Topics selected were based on a literature review and included musculoskeletal symptoms, driving behaviour, driving performance, vehicle features and the vehicle seat. In total, 903 people took part: 53.5% were younger drivers (under 65) and 46.5% were older drivers (65 years and over). Drivers over 80 years represented 7.1% of the whole sample. 59% of participants were male and 41% were female.

Musculoskeletal symptoms

High levels of musculoskeletal symptoms were reported in the lower back, knees, neck, shoulders and elbows by the whole sample. Significantly more discomfort was reported by older drivers in the hips, thighs, buttocks and knees compared to younger drivers. Younger drivers reported higher levels of musculoskeletal symptoms in the neck, shoulders and middle back, than older drivers.

In order to understand the reasons for these symptoms, the annual mileage and weekly driving hours were compared for both younger and older drivers. Older drivers reported lower annual mileage and weekly driving hours. It was also revealed that the level of activity of younger drivers, due to work for example, was greater than for older drivers. These results may be related to the reduced symptoms for the older drivers.

Driving behaviour

Respondents were given self-rated statements in this section of the survey. Half of all respondents reported that other drivers’ lights restricted their vision when driving at night. This data revealed that distraction caused by other drivers’ lights is commonly experienced by all ages; no age differences were found.

With increasing age, some decline in physical and motor capabilities is well known. Evidence of this decline was also identified in the research. Older drivers reported more difficulties than younger drivers with turning their head and body around during reversing. This result indicates that more data is needed focusing on dynamic and functional anthropometric measurements relevant to vehicle design to accommodate specific needs of older drivers, such as postures for reversing.

Similarly, older drivers reported their reactions were slower than they used to be, for example in braking in an emergency situation, compared to younger drivers. This decline, observed with increasing age, means driving tasks that require physical flexibility, such as parallel parking, can be increasingly difficult for drivers aged 65 and over.

Driving performance

Older males and females reported more difficulties with parallel parking and driving on a foggy day than younger drivers. This difficulty is also likely to be related to decline of physical capabilities as identified in the physical function part of the questionnaire. Self-rated statements were included in the survey asking respondents whether they feel distracted using navigation systems.

Compared to younger drivers, older drivers reported having less distraction when using navigation systems, although the results were not statistically significant. The reasons for this result were explored during the interviews. Older drivers stated that they were more experienced and as they tend to drive familiar routes, close attention to the navigation system was not a priority. They also tended to travel shorter distances and therefore are less likely to use these technologies compared to younger drivers. The most commonly used entertainment system is the radio among older drivers.

Adjusting the seat features

Respondents reported that they were dissatisfied with adjusting specific seat features such as the headrest height, headrest distance from the head and setting the seat belt height. Females reported more difficulty than males.

Reasons given for this difficulty included reaching, accessing and operating the controls while seated. When reaching and pulling the boot lid down to close, older females reported having less mobility and reduced reach due to them being shorter in stature.

The majority of problems identified in this research shows similarities with findings in literature. Some of these problems have existed for the past 20 years, namely, difficulty with parking, avoiding driving at night, and difficulty with turning the head and body around. Additionally, new gaps have been identified based on adjusting specific seat features. This finding indicates that there is still a need for better designed seats and seat features.

This study has provided data to understand the key issues experienced by drivers of all ages. Some issues are common for all ages, and some are age-related. Some of the problems identified in this study are similar to the ones identified in literature.

The future direction of this research will focus in more detail on understanding how design of the vehicle cab impacts on posture, comfort, health and wellbeing in older drivers.

By Sukru Karali, PhD student researching vehicle ergonomics and older drivers, Diane Gyi, Reader in Health Ergonomics and Design & Neil Mansfield, Professor of Human Factors Engineering, all from Loughborough University.

This article first appeared in Issue 530 of The Ergonomist, August 2014.