Evaluation of highway design parameters on influencing operator speeds through Casewise Visual Evaluation

Designing highways to influence driver operating speed effectively through environmental feedback is a key research field requiring special attention. Virtual reality video simulations were used to record the influence of environmental elements on driver judgments about the appropriate driving speed. This study evaluated the use of various means that could affect operating speeds and affect driver behavior without compromising safety. Data were analyzed through the fuzzy set nonlinear modeling system of Casewise Visual Evaluation methodology to identify design factors that most strongly influenced perceived operator discomfort. The findings indicated that vegetation type and density and barrier type have a significant effect on driver discomfort and thus have the potential to influence operating speeds. Roadway width has a similar effect where narrower roadways increase driver discomfort. The results indicate that roadside features and certain road design elements can be used to affect driver operating speeds.