Many roadway factors have an effect on driver behavior. Geometric, roadside, and traffic control device variables that may affect driver behavior on four-lane suburban arterials were investigated. Traffic signals and traffic volume were considered within the study site selection and data collection criteria and, therefore, were not included in the analysis. Regression techniques were used to determine how selected variables affect operating speed on horizontal curves and straight sections. When all variables were considered, posted speed limit was the most significant variable for both curves and straight sections. Other significant variables for curve sections were deflection angle and access density class. In another series of analyses performed without using posted speed limit, only lane width was a significant variable for straight sections, but median presence and roadside development were significant for curve sections. The analysis that included posted speed limit, however, produced stronger relationships between speed and significant variables than did the analysis that excluded posted speed limit.