| Driver distraction is a growing problem that is estimated to cause 13 to 50 percent of all crashes in US. Distraction mitigation strategies that focus primarily on enhancing immediate driving performance have been previously proposed in a three-tiered taxonomy (i.e., initiation type, task type, and level of automation). Another approach to mitigate distraction is to provide feedback to enhance immediate performance as well as to induce a positive behavioral change, such as diminishing the willingness to engage in future distracting activities. This dissertation proposes that feedback timing can have an impact on how feedback guides performance and behavior. Feedback timing is considered on a continuum that is classified into four major timings: concurrent (milliseconds), delayed (seconds), retrospective (minutes, hours), and cumulative (days, weeks, months). The goal of this dissertation is to demonstrate that as feedback timing increases; feedback will have a larger impact on behavior and a smaller impact on performance.; Three driving simulator studies assessed the effects of feedback timing on driving performance and behavior. The first experiment showed that concurrent feedback based on driver state resulted in less frequent glances to the display and longer glances to the roadway. The second experiment revealed that retrospective feedback (provided after a trip) and the combined concurrent (based on driver state) and retrospective feedback enhanced driving performance. Moreover, combined feedback also resulted in longer glances to the road. The final experiment investigated concurrent only (based on both driver state and driving performance) and combined feedback both when feedback was available and when feedback was no more available. Combined feedback provided significant benefits to driving performance and behavior, with a sustained effect on performance even if feedback was no longer available. This dissertation provides a firs step at understanding how different feedback timings may impact performance and change behavior, and how different timings may complement each other. |
