Color Block Task: A New Surrogate Secondary Task to Measure the Impact of Drivers’ Incrementally Increased Workload

With the increasing use of in-vehicle information system (IVIS), driver distraction, especially visual distraction, has increased dramatically. Evaluating the impact of IVIS on traffic safety is important. Previous studies have used various standard secondary-task methods in place of real IVIS interactions to obtain quantitative and scalable results. However, traditional visual secondary tasks, such as the Surrogate Reference Task (SuRT) and the Arrow Task, are insufficient to simulate incrementally increased workload with fine details or contrast difference. This study designed a new form of visual secondary task (Color Block Task, CoBT) that could provide appropriate difficulty, incremental complexity, and contrast option for visual distraction assessment. The validity of this method was tested in a driving simulator by analyzing the reaction time and accuracy of the CoBTs, the reaction time and accuracy of a Tactile Detection Response Task (TDRT), and drivers’ vehicle control performance. Results showe...