In the advent of the Intelligent Vehicle Highway System (IVHS) program, a variety of high technology in-cab devices have been proposed for use in heavy trucks and cars. These include land navigation and route guidance systems, text messaging systems, cellular phones and other communications systems, vehicle subsystem status and monitoring systems, Advanced Traveler's Information Systems (ATIS), and collision avoidance systems (CAS). Among other issues, concern has been expressed that many of these devices introduce subsidiary tasks and make information available which may compete with the driver's primary task of safely controlling the vehicle at all times. The challenge of design, evaluation, and implementation of high technology from a driver-centered perspective is to determine the efficiency, effectiveness, and safety of such devices.

Battelle, with its subcontractor R&R Research, Inc, and a team of consultants, is under contract to the National Highway Traffic Safety Administration (NHTSA) to develop a workload assessment protocol suitable to assess the safety implications of high technology systems that might be introduced into heavy trucks. There is every expectation that the workload assessment protocol will also be applicable to cars This effort includes task analysis, literature review, definition of a baseline heavy vehicle configuration, workload assessment protocol development, data collection, and evaluation of two devices with the developed workload assessment methodology This work will contribute to identification of biomechanical, perceptual, cognitive, and response demands imposed by high technology devices.

As part of this effort, Battelle has considered the problem of Workload assessment methods and measures. A variety of measures and methods have previously been developed to evaluate in-cab devices in terms of driver Workload. These range from analytical tools to on—the-road testing with an instrumented vehicle. Device attributes, subjective assessments from drivers, driver behaviors, and driver-vehicle performance all provide useful information on the potential of a device to compete with the driving task for the driver's attention and resources. This paper will present an overview of those measures and methods which have proven useful in assessment of selected in-cab devices. The implications of these techniques and protocols for safety evaluation of IVHS in-cab driver interfaces will be addressed.