Study Of Headway Of Roundabout

Roundabout is an intersection of self-regulation, with many of its advantages, with the social and economic development, increase in the number of motor vehicles, the increasing urban traffic congestion a significant problem, in this environment Roundabout how to maintain their own advantages, ease traffic congestion is an urgent research topic, in this environment at home and abroad for research more and more roundabout.Headway is a microscopic traffic flow characteristics of one of the most important parameters to study the distribution of headway is to calculate the intersection capacity, vehicle delay, set the signal flag, an important basic parameter; is for traffic simulation and other transport activities basis. Critical gap as a special headway on the calculation of capacity and traffic flow simulation has a great impact. Therefore, this paper studies headway distribution and special value for analysis.In this paper, Shuma Plaza, Xueyuan Plaza, two Roundabouts headway actual observations, and for sub-Drive fitting, use a negative index and the M3 distribution model fitting, and derive the annular flow zone and the front part of the weaving section the distribution of time-distance, that is a negative exponential annular flow region and the M3 distribution; basic line in the mixed zone to obey M3 distribution, high flow situation is neither negative exponential distribution is not subject to M3; and vehicles based on the actual need to insert Multi Drive combined cycling equivalent of headway distribution are studied, found that the equivalent headway distribution when t> 1.41 when the subject M3 distribution model. This article is also on the macro and then traffic flow - traffic and the headway of the relationship between the analysis shows that the flow rate and average headway into the power function, the minimum headway in the 1s or so, and although there is reduced flow to increase trends; there to obey traffic divided threshold value distribution model. Finally, Ashworth and through the application of maximum likelihood estimation, respectively Shuma Plaza, Xueyuan Plaza, the critical gap of two circular cross the actual calculations, and the results of a simple analysis.