Abstract
Human factors research in transportation safety has not clearly demonstrated how experimental behaviors are related to public driving behaviors. The appropriateness of determining external validity measures has been debated, and it is known that external validity is not a necessary component in research if those findings do not need to transfer outside of that context; however, results in the transportation safety community are frequently generalized, if improperly, to a stated risk in public driving situations. Few studies have validated driving behavior between experimental and non-experimental (observed behavior in public) settings. Proposed is an empirical method to establish a baseline of non-experimental driving behaviors to compare with experimental driving behaviors. This method involves video recording public driving behaviors during the same time interval that data collection occurs in the real world (instrumented vehicle) and virtual world (driving simulator). These video recorded non-experimental driving behaviors at locations along an experimental route can then be compared to experimental driving behaviors in instrumented vehicles and driving simulator scenarios (if developed) to establish empirical differences and potentially contribute to measures of external validity. This method introduces collecting non-experimental driving behavior in order to establish methods that will generalize experimental results as they relate to public driving situations.