An investigation on capacity and delay of freeway on ramp junctions

Traffic congestion cause time loss for drivers and negatively affect the natural environment due to excess fuel consumption especially in metropolitan cities. Although the reason for traffic congestion is considered to be a result of insufficient road investments; effective usage of existing facilities is among the other causes of the traffic problem. Various merging control applications are carried out in order to operate high cost investments such as freeways efficiently. Although merging control applications are quite in limited numbers in our country, it provides effective results especially in high traffic flows such as peak hours. Delays in the merging section should be determined in order to be able to use merging sections of the freeways effectively and to assign the situations where merging control applications are required. Within the scope of the thesis, the main methods for determining the capacity of freeway merging section are explained; the gap acceptance theory, which is the most common method in the literature, is discussed by using data collected from the field and the value of the service delay with respect to the arrivals of the vehicles approaching from an upstream signal located on an urban arterial, is tried to be determined. With the help of AIMSUN, which is one of the simulation programs frequently used by traffic engineers, a model of freeway merging section is created. In this way, different geometry, volume and delay values are obtained. Finally, using the data obtained from the simulation program, Partial Least Squares Regression method is applied for modeling delays in the merging section and an equation is proposed. The effect of delays on the performance of the merging section is examined by using the outputs of the model.