Analysis of the Effect of Square Geometry design on its Functional Characteristics Using the Aimsun Traffic Simulator Software

The researchers introduced various geometric designs for the fields. So far in Iran, despite the high exploitation of the field, precise studies have not been conducted on the subject of the study and comparison of its behavior. In this study, the values of time-delay traffic indicators, velocity and capacity of Aimsun traffic simulation were studied and compared. In the simulation done, there are seven cycling modes and some geometric characteristics such as the number of lines entering the field, Number of lines around the field, the angle of the branch (along the street), and the diameter of the central island of variable, and some other; line width, input radius to the field, the input speed to the field and the speed round the field are considered constant. Based on the results of this study, by increasing the number of street line (when the angle of the branch is 50 degrees, the number of line of the field is 3-line and the number of street line increases from 1 line to 2 lines), the delay increases by about 50 percent and the speed decreases by about 30 percent or by increasing the number of field line (when the angle of the branch is 70 degrees, the island diameter is 100 meters, the number of the street line of the 2- line and the number of field line increases from 2 lines to 3 lines), the delay will decrease by 12 percent and the speed will increase by about 10 percent. As the diameters increase (when the angle of the branch is 90 degrees, the number of the street line is 2-line and the number of the field line is 3-line), circulating situations that is more turning to right, the delay will decrease by 28 percent and the speed will increase by 16 percent and situations that is more turning to left, the delay will decrease by 36 percent and the speed will increase by 23 percent