Research On Minimum Distance Between Interchanges On Urban Expressway

Interchange is an important part in freeway and traffic system. The local governments of many cities spend a lot of funds on interchanges construction of the city circle and expressway as a modernization sign. However, our planning and design technology of interchange is far from perfect. Traffic jams and accidents happen occasionally on roads because of unreasonable interchange spacing in city circles and expressway, and on/off-ramp junctions become bottlenecks of the traffic system. Therefore, research on minimum distance between interchanges has great significance for removing those bottlenecks, improving freeway capacity and determining freeway level of service.The main body of this dissertation is made up of eight chapters. Firstly, the factors affecting the distance between interchanges, such as lane changing behavior and traffic sign standards, were analyzed. Secondly, based on a lot of analysis and processing on the data collected, the characteristics of traffic flow and driver behavior were studied. Thirdly, with statistical methods and regression techniques, the rules of flow rate and headway distribution for the segment between interchanges were found. Fourthly, the primary factors were calculated and the minimum distance model was established. Then, with the model, the minimum distance between interchanges was worked out in different freeway conditions. Finally, the traffic flow of the segment between adjacent interchanges was analyzed with the help of the traffic simulation software named TSIS.