Search Results

A class of driver attentional workload metrics has been developed for possible application to the measuring and monitoring of attentional workload and level of distraction in actual driving, as well as in the evaluation and comparison of in-vehicle human machine interface (HMI or DVI) devices. The metrics include driver/vehicle response and performance measures, driver control activity, and driver control models and parameters. They are the result of a multidisciplinary, experimental and analytical effort, applying control theory, manual control, and human factors principles and practices. Driving simulator and over-the-road experiments were used to develop, confirm, and demonstrate the use of the metrics in distracted driving situations. The visual-manual secondary tasks used in the study included navigation destination entry, radio tuning, critical tracking task, and a generic touch screen entry task.

A study of the effect on driver behavior and performance of varying occlusion parameters and secondary task duration was accomplished using the Dynamic Research, Inc. (DRI) Driving Simulator. Driver glance behavior and performance under comparable primary and secondary task conditions that were driver paced (no occlusion) were studied also. Both occlusion goggles and screen blanking means to interrupt vision were investigated. The several experimental phases included baseline primary driving task only, baseline secondary task only (no occlusion), secondary task with occlusion or screen blanking, primary driving task with goggles occlusion, and primary and secondary tasks combined, driver paced, with no occlusion or screen blanking. The secondary task human-machine interface (HMI) was a generic alpha entry task using a touch screen, located high in the center console.

An over-the-road study of driver destination entry using an example in-dash GPS-based navigation system was accomplished in traffic on urban surface streets and freeways. The evaluation used typical drivers, and a vehicle instrumented to record driver control inputs, vehicle response motions including lateral lane position, and driver eye glances and fixations. The primary task was to follow the routes in a safe manner, while moving with traffic and maintaining speed and lateral lane position. As a secondary task, the drivers entered the successive destinations while driving, using a touch screen, and at their own pace. They were told there was no hurry, nor was there a need to enter the destination quickly. Results are shown for number of keystrokes, total fixation times, number of fixations on the device, fixation duration, lane keeping performance, and subjective ratings related to ease of destination entry.