Using Analytical Models to Calibrate a Dual-Roundabout Intersection in Microsimulation

A Novel Methodology for Estimating the Capacity and Level of Service for the New Mega Elliptical Roundabout Intersection

“…Step 7: determine the radius of basic ellipse roadway, entry radius, exit radius, and ellipse elements (a and b). AASHTO [70] proposed equation (13) to estimate the radius of basic ellipse roadway, entry radius, and exit radius.…”

“…is is probably because mega elliptical roundabout island has an ellipse element (b) for providing a suitable radius for basic ellipse roadway in order to be appropriate for heavy vehicles that make a U-turn on basic ellipse roadway. is radius is calculated based on the average speed for vehicles on weaving sections from equation (13).…”

“…Based on the previous studies, intersection analysis models generally fall into three categories: simulation models, empirical models, and analytical models. Simulation models are useful in the initial feasibility analysis of new types of intersections which do not have Highway Capacity Manual (HCM) procedures and in comparing them with current intersections [6][7][8][9][10][11][12][13][14]. Empirical models rely on field data to develop relationships between geometric design features and performance measures such as capacity and delay [15][16][17][18].…”

“…6%] for the average speed, while the relative error range was [− 3.5%,13.4%] for the density. e main cause of the existing relative error was the random VISSIM simulation results which led to some deviations from the average speed and density in the estimated models.…”