Development of a local operating speed model for consistency analysis integrating laser, GPS and GIS for measuring vehicles speed

Design consistency refers to the condition whereby roadway geometry does not violate driver expectations. As such, most evaluations of highway geometric design consistency are based on operating speed profile analysis, which relates safety with speed variability. This paper presents a new operating speed model in which the operating speed depends on curve radius. The model uses car speeds collected for 42 curves on two-lane rural highways in Southwest Spain. A comparison between this model and several models developed previously in other European countries has been made. This comparison emphasizes the influence of the model chosen on the results obtained. In addition, the incorporation of laser, GPS and GIS for vehicle speed measurement in the inexpensive yet reliable manner is discussed.