Research On Mixed Traffic Flow Characteristics At Signal Intersections

Urban traffic control system is an effective mean that take full advantage of road infrastructure to improve the traffic capacity of intersections and increase the safety factor. Mixed traffic is the main characteristic of urban traffic in China, and also is the main reason of the lowering traffic capacity and increasing delay of intersection. But the present urban traffic control system lack of the support of the mixed traffic, often has poor control effect. It is necessary to research systemically the theory of mixed traffic and to integrate it to the present urban traffic control system. This paper study further the characteristic of mixed traffic at plan intersection based on the project of "Research on the theory, algorithm and simulating technology of self-adapted control system on mixed traffic" with Hisense Network Technology Co, Ltd.Conversion factor of vehicle and bicycle is raised in the study of traffic capacity and is used in the conversion of mixed traffic flow and 100% standard vehicle, which aims to make mixed traffic values of various roads and traffic conditions comparable, and thus establishes the importance of conversion factor in the calculation and comparison of traffic capacity. Most of the study of mixed traffic problems finally comes down to the calculation and comparison of 100% standard vehicle, so conversion factor is the fundamental problem and is the key step of the following study. With the spread of study of traffic capacity in the forties of 20th century, there has never a break in this area, but not any acknowledged algorithm has been set up till now. So, assertion of conversion factor of non-motorized vehicle is firstly presented in the second chapter. Traffic engineers make this factor equal 0.2 to convert the non-motorized vehicles in all situations, not considering straight bicycles different from left turn bicycles. In this paper, based on the quantitative research on the mutual influence between the left turn bicycles and straight bicycles, we present a new method to calculate the conversion factor of the straight bicycles and the left turn bicycles and apply the survey data from Tianjin city and Shenyang city to validate the models. Then we can obtain that the straight bicycle conversion factor is 0.275 and the left turn bicycle conversion factor is 0.33. Although the field data are finite and the result can not be used widely, the result questions the usual conversion factor. Additionally, the method suggested in the paper can also be used for reference.It is essential reason that in the intersection the conflicts between non-motorized vehicles and motorized vehicles, pedestrians and motorized vehicles make the capacity of this intersection decrease. The research on the arrival and departure characteristics in the intersection of non-motorized vehicles and pedestrians, searching the traffic character parameters of bicycle flows and pedestrians of urban signalized intersections can overcome the shortcoming of the conventional signal-timing parameters that only based on the motorized vehicles' traffic character and provide effective mixed-flow organization of urban signal-control intersection with academic proof. In fact, the research domestic and abroad in the field is too limited to meet the demand of modern traffic management on mixed traffic. Therefore we make the systemic research on the arrival and departure characteristics in the intersection of non-motorized vehicles and pedestrians in the third chapter. We find that the arrival characteristic of the bicycle and the pedestrian has negative binomial distribution after using method of mathematical statistics on survey data, which is tested by χ2 test. According to the arrival characteristics of vehicles and pedestrians, we get that the velocity of bicycle is centralized around 11~12km/h in the situation of saturation flow and on 13~15km/h in the situation of free flow. Further more, the larger the intersection is, the higher the velocity of bicycle is. And the mean value of saturation flow per meter is 1.0...