Estimation and Development of Saturation Flow Model for Urban Arterial Road Intersection

Saturation flows, lost times and Passenger Car Units (PCU) is the significant parameters in the planning, design and control of signalized intersection. The accurate estimation of Saturation flow values is prime importance when determining the capacity of signalized intersection. Saturation flow is important for estimating signal green time. This discusses a saturation flow study conducted in Income tax intersection of Ahmedabad city, the commercial city of Gujarat, which lies in the west of India. The Saturation flow rate is calculated based on the observed green time. The objective of this paper is to collect a large sample of field measurements so that reliable saturation flow values could be obtained and the result identified several factors which has significant influence on saturation flow. Models are developed for the saturation flow considering width of approach, traffic compositions and gradient criteria. A formula was recommended for use in estimating an appropriate saturation flow value for a specific lane on an approach to an intersection. Many researchers have developed models for saturation flow. These models do not match with field data. The developed Models of saturation flow give the correct value of saturation flow. These developed models are calibrated & validated with field observed data.