Abstract:

Minimum delay (or service delay) is one of the most important performance measures for intersection analysis. It can be described as the delay to a vehicle, which is waiting at the stop (or yield) line of an unsignalized intersection. In this study, an appropriate minimum delay equation is derived for multi-lane traffic circles in İzmir, Turkey. For this purpose, observations are made at six approaches of five multi-lane traffic circles. Simple and multiple regression analysis, in which circulating flow and geometric parameters are chosen as independent variables, are used to model minimum delay. Results have shown that geometry of a traffic circle has an important effect on minimum delay and should be considered in analysis but the model may fail to define minimum delay values greater than 22 seconds. Analyses have shown that models which depend on entry capacity are more effective in estimation of minimum delay at multi-lane traffic circles.

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