Designing and Operating Safer Highways for Older Drivers: Present and Future Research Issues

A major shift is occurring in the population age distribution resulting in a growing number of older persons with an increasing demand for mobility. For a variety of reasons, meeting the present and future mobility needs of older persons will depend primarilary on the automobile. This paper will discuss key issues related to ongoing and planned research sponsored by the Federal Highway Administration (FHWA) to improve the mobility and safety of older drivers and pedestrians. The scope of FHWA research activities concerns aspects of highway design and operations that involve direct user interface. For example, geometric design and traffic control device standards explicitly consider quantifiable driver characteristics such as perception-reaction time or visual acuity. Ongoing research is addressing the extent to which existing traffic control device elements accommodate drivers with age-related diminished performance capabilities. Current work is testing older driver responses to brighter and larger signs with varying legend spacing and font characteristics in order to make recommended changes to existing highway signing standards. Older driver perception-reaction time is being evaluated in a variety of intersection, stopping, and decision sight distance situations. Studies are also underway to improve pavement markings and delineation systems to enhance their utility for older drivers. Driving simulation and field methods are being used to investigate vehicle maneuvers which cause difficulties for older drivers so that improvements can be made to highway design and operations. Future studies will determine the capabilities and limitations of older pedestrians, address the visibility problems of symbol signs and changeable message signs, and investigate all aspects of intersection design and operations in light of older driver and pedestrian capabilities.