Modeling Traffic Flow at an Urban Unsignalized Intersection

This paper proposes a new way to study traffic flow at an urban unsignalised intersection, through detailed space considerations, using cellular automata (CA). Heterogeneity and inconsistency are simulated by incorporation of different categories of driver behaviour and reassignment of categories with given probabilities at each time step. The method is able to reproduce many features of urban traffic, for which gap-acceptance models are less appropriate. Capacities of the minor-stream in a TWSC intersection are found to depend on flow rates of major-streams, also changes with flow rate ratio (FRR= flow rate of near lane: flow rate of far lane). Hence flow rates corresponding to each stream must be distinguished. The relationship between the performance of intersections and other traffic flow parameters is also considered. Vehicle movements in this paper relate to left-side driving, such as found in UK/Ireland. However, rules are generally applicable.