Measuring Distraction: Task Duration and the Lane-Change Test (LCT)

Considerable research activity (e.g., HASTE, CAMP, ADAM projects) is currently focused on producing protocols for assessing the distraction potential of in-vehicle tasks and devices. The Lane Change Test (LCT) is a relatively simple and low cost standardized test scenario designed for measuring driver distraction. The purpose of the present study was to evaluate the LCT's ability to discriminate between different secondary tasks with different levels of workload. The LCT was used to assess the driving performance of twenty-one drivers while they performed typical navigation tasks, Point of Interest (POI) Entry and Destination Entry, each with a low and high workload version. The experimental set up included a steering wheel, foot pedals, monitor, computer and navigation system, all off the shelf. The results indicated that the LCT is a sensitive measure of driver distraction. The participants showed greater mean deviation in lane change path when driving while performing a secondary task (i.e., calibration and navigation tasks) than when driving without performing a secondary task (i.e., baseline). When driving while performing secondary tasks, drivers showed differences in lane change path deviations as a function task type and task complexity. These differences were also reflected in participants mean task time to complete the secondary tasks. The present research provides evidence that the LCT metric of lane change path deviations discriminates between different types and complexity levels of secondary tasks, and that these differences are a function of time taken to complete the secondary tasks.