Measures which relate to the vehicle are aimed at improving the physical access to the car, at making it easier to operate the vehicle, or at improving the safety of the occupants. The first two types of measure primarily relate to vehicle design, the latter to vehicle safety.
Vehicle design
Age-related mucular-skeletal impairments such as ostheoarthritis, rheumatoid arthritis and decreasing strength may all affect the range of motion of limbs, making it more difficult to enter and exit vehicles and to reach driving controls or handle the steering wheel. To facilitate older people's entry and exit of a car, door frame height, width of door opening, doorsill height and seat hight should have the right dimensions:
| Car part | Recommended dimension (cm) |
|---|---|
| Door frame height above ground | 133-138 |
| Width of door opening | 80-100 |
| Seat height above ground | 50-60, 50 optimum |
| Doorsill height | 36-40 |
| Doorsill to car floor | 4-9, 6 optimum |
| Seat front edge | 35-45 |
| Door opening angle | 70 , 90 when assistance needed |
Source: Institute of Consumer Ergonomics, 1985; Petzäll, 1991, cited in OECD, 2001
In addition, handles on the doorframe can help during entry and exit of the car. Equipment that can make it easier to operate the vehicle are power steering, automatic transmission, and wide-angle and planar rear-view mirrors to support drivers suffering from impaired field of vision or restricted head movements. Finally, Advanced Driver Assistance Systems (ADAS) such as in-vehicle signing systems and night-vision enhancement systems can also compensate for functional limitations.
Vehicle safety
Older adults are more vulnerable than younger adults: their injuries will be more severe given an identical collision impact (see fatality ratio). Given the estimated increase in the number of older drivers, improved crashworthiness of vehicles is very important. Currently, crash-test dummies and models are based on average fit people. Test dummies capable of modelling the effects on an older occupant are needed to be able to take into account the older occupants' frailty when testing and improving vehicle safety.
In addition, occupant protection should be enhanced by further development of seat belts and airbags, particularly through force-limiting features. In their current state of development, seatbelts are beneficial to older occupants. However, in some circumstances, they may also contribute to the incidence of chest injuries. Recent developments suggest that this drawback is well on its way to being resolved, by the use of a 'force limiting feature', which controls the maximum restraining force exerted by the shoulder belt. Other technological advances that are likely to be especially relevant for the protection of older occupants include (Pike, 1989, cited in OECD):
- Intelligent restraint systems, capable of adjusting for lighter, older occupants
- Dual-stage airbags to minimise aggressive airbag contacts in moderate crashes
- Active head restraints to minimise soft tissue injury and whiplash injuries to the neck
- Side airbags to protect the head and chest in side collisions, such as crashes when turning left in which older drivers are overrepresented.