Thought Leadership

Modeling High-Capacity Multi-Lane Roundabouts

Author:  Ravi Ambadipudi, PE, PTOE

RODEL and SIDRA are two of the most common macroscopic roundabout operational analysis tools being used in the United States. One significant drawback of the macroscopic tools is that they cannot address complex interactions between roundabouts being analyzed and adjacent intersections.

Analysis of interaction between the operations of closely spaced intersections becomes critical in urban settings where peak-hour traffic volumes are high. Only microscopic traffic modeling tools can analyze such interactions.

This paper provides some guidelines for multi-lane roundabout operational analysis using the microscopic traffic simulation tool VISSIM. Comparison of results from VISSIM to those from RODEL and SIDRA also is provided. The purpose of this paper is to provide guidelines that make the best use of the three widely used roundabout analysis tools.

  • Priority Rules
  • Simulation Resolution
  • Model Development in RODEL & SIDRA
  • Modeling Procedure
  • Reduced Speed Areas
  • Estimation of Priority Rule Parameters Based on Speed Variables
  • Multiple Model Runs
  • Model Development in VISSIM
  • Results & Some Observations