VISSIM is one of the popular tools to model roundabouts in the United States. Because of its flexibility in modelingdriver behavior and in creating accurate roadway geometry, VISSIM is being increasingly used as part ofroundabout operational analysis. Like any other microsimulation tool, accuracy of the traffic performance measuredin VISSIM is largely dependent on how well it is calibrated. With varying familiarity of roundabouts among UScommunities, it is imperative to calibrate VISSIM to local conditions. However, lack of field data for USroundabouts and the complexity in VISSIM’s underlying algorithms have made VISSIM calibration a challengingtask. Additionally, limited guidance from previous research is available to assist practitioners to select appropriateVISSIM parameters for capacity-based calibration.This paper evaluated the impact of various VISSIM parameters on the simulated roundabout capacity, andsubsequently developed three capacity-based calibration strategies. A case study was established based on a singlelaneroundabout in Carmel, Indiana. The calibration strategies were applied to adjust the simulated roundaboutcapacity to match two target capacity models. Although the calibrated values are not “transferable”, the generalcalibration process and the calibration strategies are expected to be applicable to other single-lane roundabouts.
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