ITS TECHNOLOGIES AND MATURE DRIVERS

This report presents the findings of a research project pursued by a faculty-student team from Arizona State University in cooperation with the Arizona Department of Transportation (ADOT), Arizona Transportation Research Center and the Maricopa Association of Governments. The research focused on the perception of older drivers of Intelligent Transportation System (ITS) technologies, specifically those deployed on the urban freeway system in the Phoenix Metropolitan Area. A series of 11 focus group sessions held with drivers over age 65 from fall 2003 to spring 2004 provided the primary source of information on perceptions of ITS technologies. Both year-round residents and winter visitors were represented in focus groups that were held in a variety of locations and settings across the Phoenix urban area. One additional focus group with drivers aged 40 to 55 served as a control group. The study emphasized three technologies--variable message signs (VMSs), portable VMSs, and ramp meters. Focus groups and an additional group of older drivers in two heuristic user evaluation sessions also assessed the evolving ADOT Advanced Traveler Information Systems (ATIS) effort that includes both a dedicated interactive 511 telephone highway conditions reporting system and an AZ511.com website that provides almost real time highway conditions reports. An assessment of freeway on-ramp accidents involving older drivers for the period 2000-2003 offered a basis for a more objective review of the challenges faced by older drivers. The older drivers involved in the study were frequent users of the Phoenix urban freeway system, and were generally enthusiastic about the ITS devices that they felt responded to some specific challenges they faced while driving on freeways. They offered relatively small changes that would enhance their effectiveness. Large VMSs with 18-in. yellow fiber optic letters displayed against a black background caught the attention and were far easier to read than standard highway signs. Drivers urged using them only to convey short, specific directions to current roadway users. Portable electronic signs captured attention near construction sites, but placement only on the right side of the freeway limited visibility. Legibility was a significant concern and double phased signs were particularly challenging to read in time to process information effectively. They preferred sequential signs mounted high above trailers. Ramp meters not only helped the flow of traffic, but also benefited older drivers by providing about 4 seconds to find a gap in traffic. Accidents have declined at on-ramps; the ramp meters and new acceleration lanes have both played a role. Older drivers also have identified key elements that they believe will enhance the usability of both the evolving 511 and AZ511 systems.