Investigating the Effect of Lane Width on the Saturated Flow Rate of the Signalized Intersections

So far, many studies have been carried out to evaluate the saturation flow rate at the entrance of the intersection, in accordance with geometric characteristics, traffic flow characteristics, and driver behavior. While, despite the difference in the above specifications, there is no study on saturation flow rate at inter-section exit and due to the difference in saturation flow rates between entrance and exit, in the case of decreasing lane numbers, decreasing lane widths and other effective factors, the importance of determining the capacity of the saturation flow rate in the exit is also important. In the present study, with the help of field data acquisition at five signalized intersections pilot in the city of Rasht, the determination and analysis of saturation flow rates using macroscopic and microscopic methods are considered, considering the width of the lane in the entrance and exit branches of the intersections. The results show that saturation flow rates in the exit branch are microscopically higher than those in the entrance branch. There is also a linear correlation between lane width and saturation flow rate in the exit branches by macroscopic method with a correlation coefficient of 0.957. Regarding the correlation coefficient of the exit branch, the lane width seems to be the main criterion in determining the flow rate, while in the entrance branch; more parameters are needed to determine the flow rates.