Research On The Methods Of Right-Turn Followed By U-Turn At T-Intersections

In recent years, it becomes common along the city arteries that left-turn vehicles from the minor road are forbidden to make a direct left turn (DLT) to the major road, which can contribute to the eliminating of capacity affect to the major road. At the same time, right-turn followed by u-turn (RTUT) is implemented for the left-turn vehicles at the minor road as an alternative way. However, both methods have advantages and disadvantages. So the method of RTUT is chosen as the topic of the paper. The main subtopics of the paper include the choose method between DLT and RTUT, the analysis method of the affect on the capacity of signal intersection, the estimation of the capacity of U-turn at unsignalized intersections and the optimization method of the opening location on the median.The paper consists of seven chapters. The first chapter is Introduction. The background and objective of research are explained and the main content and research approaches of paper are summarized. The title for the second chapter is the Analysis of Movement for DLT and RTUT. As the basis for the subsequent chapters, the moving procedures for both DLT and RTUT are compared to make the conclusions for the advantages and disadvantages. Besides, the implement methods are introduced from the practice view. The title for the third chapter is the Choose Method between DLT and RTUT. The ultimate goal of this chapter is guiding traffic engineer how to decide each traffic method. Both the mathematical models drawn from Gap Acceptance Theory and the field measurement method based on the video collection are discussed in the third chapter, which can be an effective makeup in practice. The title for the fourth chapter is the Analysis on the Affect of Capacity at the Downstream Signal Intersection. The essence of capacity is emphasized at the beginning section of the chapter. Then the measure method for saturation flow is introduced based on the difference between left-turn vehicles and u-turn vehicles. According to the typical research from United States, the importance factors which must be obeyed in field research are pointed out for the selection of intersections. The title for the fifth chapter is the Estimation for the Capacity of U-turn Vehicles at Unsignalized Intersections. The basic model for the calculation of capacity of u-turn is introduced to contrast the difference between the general road section and unsignalized intersections. The complex situation of unsignalized intersections is shown by the conflict analysis method. The Kyte method and HCM procedure are studied for the topic. The title for the sixth chapter is the Optimal Location of U-Turn Median Openings on Roadways. The major conclusion of this chapter is achieved by the comparison between RTUT at urban arterial and waving area at expressway. Since the HCM method for waving area is not applied for the u-turn, an optimization process is developed based on the minim delay. The seventh chapter is Conclusion. The main progress of research and important conclusions are summarized. The future work is concentrating on the enriching the research content, reference countries and research means.