SUPPLEMENTAL ELECTRONIC IN-CAB TRUCK DISPLAYS: AN INVENTORY OF DEVICES AND APPROACHES TO THEIR EVALUATION. FINAL REPORT

Today's medium-heavy truck driver, in many situations, operates under a heavy visual and attention workload. The driver's primary task is to maneuver his vehicle safely to its destination--a task which requires, at times, virtually uninterrupted visual monitoring of the roadway and relevant traffic events. Over the past few years there has been significant growth in the availability and use of supplemental electronic display devices. Most are clearly of benefit to drivers or fleet operators by virtue of their enhancement of operating efficiency, lower operating cost, driver control and maintenance scheduling, to list but a few. The inherent complexity of the driver-user/device interface, however, may be such that use of such devices during driving will decrease safety by increasing crash involvement, since they compete with the primary task of continuous roadway monitoring. A study was undertaken to 1) inventory current and near-term electronic supplemental in-cab displays, 2) estimate their use in the 1990s by truck type, and 3) identify alternative strategies for their evaluation relative to their compatibility with safe truck operation. Over 50 supplemental in-cab devices were identified and described and are classified under the following headings: Single/Integrated Display Systems; Vehicle Information Systems; Vehicle Navigation Systems; Vehicle Positioning Systems; Text Communication Systems; and Vehicle Safety Systems. Visual, motor and cognitive processing demand on the driver/user was estimated. A preliminary examination indicates that many devices impose a very heavy demand on the user and are designed to be used during driving, a situation which clearly will lead to decreased truck safety. The anticipated proliferation of such devices will no doubt lead to a broad highway safety problem. Short and long range objectives and safety evaluation strategies are outlined and a plan for research to describe and quantify current truck driver workload, fundamental to any subsequent safety evaluation, is presented.