Oregon State University
The study responded to trucking industry concerns that certain roundabouts unduly delay heavy vehicle traffic. Oregon State University collaborated with Robinsight to investigate how vehicles — especially heavy vehicles — navigate the Sisters and Fyfe roundabouts.
Approach
- GPS Event Identification – Isolated vehicle movements around and through the Sisters and Fyfe roundabouts, filtering for relevant turning events and path segments.
- Traversal-Time Model – Estimated how long vehicles took to circulate each roundabout, including circular speed dynamics. Imputation techniques filled gaps where GPS data was incomplete.
- GPS and On-Site Survey Integration – Ground surveys validated GPS-derived metrics, ensuring robustness and credibility in the analysis.
- Research Report for ODOT – The study culminated in a formal paper presented to Oregon Department of Transportation, offering unbiased evidence on roundabout delay characteristics with particular emphasis on heavy vehicles.
Impact
- Delivered clear, quantitative insights into how heavy vehicles and other vehicles move through critical roundabout locations, helping challenge or confirm stakeholder perceptions.
- Informed ODOT's operational assessments and potential design refinements.
- Demonstrated the value of integrating GPS and field observation methods in evaluating traffic control infrastructure.