Study On Interference Mechanism Of Mixed Traffic Flow At Signalized Intersections

Mixed traffic, composed with motor vehicles, bicycles and persons, is a typical characteristic in China city. The interference and conflict phenomenon, between motor vehicles and bicycles, reduce the traffic capacity of intersections severely and increase the hidden traffic troubles. Mixed traffic is a complicated system with serious nonlinear, strong stochastic and time varying characteristics. To solve the problem of urban mixed traffic, it is needed to systemic study on mixed traffic flow. This research is aims to study the mixed traffic flow and interference principles at signalized intersections, micro behavior models and nonlinear dynamic characteristics and other key problems. Some micro behavior models of mixed traffic flow are developed. This can provide basis to improving the traffic efficiency and management of signalized intersections.First, the interference principles of mixed traffic flow at signalized intersections have been studied and the characteristic of interference principles are also analyzed. The conceptions of interference region and interference grade are proposed, which will provide theoretical basis for qualitative and quantitative analysis of interference questions. Based on nonlinear car-following theory, the deceleration model before intersections, car-following model at intersections and the acceleration model departure from intersections of right-turning motor vehicles are developed. Through researching the micro behavior characteristics of motor vehicles at signalized intersections, a behavior judgment model about right-turning motor vehicles traversing straight-going bicycles is proposed and developed.The single bicycle simulation models, including deceleration and parking, acceleration and departure as well as traversing, are established by researching the characteristics of transverse and lateral movement at intersection. And a two-dimensional simulation model is also established to represent bicycle group's micro behavior at signalized intersections.The generation principles of traffic flow's chaotic phenomena and its dynamic characteristic have been studied. A little data volume method is proposed to fast calculating shot period traffic flow time series maximum Lyapunov exponent based on chaotic time series. The identification outcome is verified by Poincare section. The part fractal characteristic of short period traffic flow is analyzed using minimal cover dimension. The relationship between minimal cover dimension and short period traffic flow fluctuation is determined. And a minimal cover dimension method that can estimate short period traffic flow variety is proposed.A micro simulation system framework of mixed traffic at signalized intersections is developed based on multi-agent theory. The micro behavior characteristics of mixed traffic flow are re-showed by computer simulation. These models are validated separately with field data and simulation results.