This paper presents a methodology to estimate the volume of large trucks by using single loop outputs. An Unscented Kalman Filtering (UKF) algorithm is used to generate speed estimation based on single loop data, and the mean effective vehicle length of each time interval is thus obtained with the loop outputs and speed data provided. We investigated the bimodal vehicle length distribution and further separated it into short and long vehicle distributions. Based on the estimated mean effective vehicle lengths and vehicle length distributions, an algorithm is proposed to estimate large truck volume. Data collected from Texas Transportation Institute's vehicle detection test beds are used for this study. The results show that the proposed method produces good performances in large truck volume estimation under various traffic conditions.
Samenvatting