Estimating the Effect of Speed Control Strategies on Speed Distribution in Work Zones with Quantile Regression

Speeding has long been a safety concern for transportation and law enforcement agencies, and speed control strategies also have received great attention; however, a review of the literature revealed several issues. To overcome these identified issues and better evaluate the effectiveness of some enforcement strategies, the authors used a new method, Quantile Regression, to analyze the speed data collected from a designed experiment. Quantile Regression is capable of simultaneously estimating the entire distribution of speed, free of distributional assumption, and represents a significant improvement over the current methodologies. Quantile Regression was used in this study to estimate the effectiveness of police enforcement on speed control in work zones, and its strengths compared to traditional methodologies were fully demonstrated. New knowledge was obtained, and the best speed enforcement strategy was identified. Based on the theoretical merits and the empirical results from this study, it is strongly recommended that Quantile Regression be considered for all future studies concerning speed control strategies.