Resumen
This study investigates Japanese drivers? over-speeding violation behaviors on expressways captured by a GPS-enabled smart phone App, called Safety Supporter and designed by the authors, with functions of both second-by-second safety diagnosis and traffic warning information provision as well as advices about safer driving. The research purpose is to clarify the effects of the App on safety improvements based on data from a three-month field experiment in 2014, where a series of questionnaire surveys were conducted. For the research purpose, a zero-inflated negative binomial regression model is adopted to represent over-speeding violation behaviors. As a result, drivers? heterogeneous responses to the App functions are confirmed with a focus on the role of driving safety change stages and the results highlight the importance of individualized safety measures.