Date of Award
2026
Document Type
Thesis
Degree Name
Master of Science in Engineering (MSE)
Department
Civil Engineering
Committee Chair
Michael Anderson
Committee Member
Ashraf Al-Hamdan
Committee Member
Henrick Haule
Research Advisor
Michael Anderson
Subject(s)
Traffic flow--Computer simulation, Roads--Interchanges and intersections, Roads--Alabama, Traffic engineering
Abstract
Diverging Diamond Interchanges (DDIs) are increasingly used to improve traffic flow and safety, particularly where left-turn volumes are high. However, their operational performance under high heavy vehicle percentages has not yet been evaluated. This thesis investigates the impact of varying HV percentages and traffic volumes at a sample DDI location. Traffic simulation using Synchro software was used to model the DDI under scenarios with varying heavy vehicle percentages and varying volumes. This approach allowed evaluation of traffic growth and increasing heavy vehicle presence on DDI performance, capturing realistic operational conditions for freight-heavy corridors. Key performance measures included average control delay, level of service , and volume-to-capacity ratios. Results show that the DDIs operation failure occurs for the west intersection at approximately 61% HV under baseline traffic, dropping to 29% and 6.5% HV under 25% and 50% traffic growth scenarios. These findings provide guidance for transportation engineers considering DDIs in freight-heavy corridors.
Recommended Citation
Duke, Hannah, "Evaluating the operational performance of diverging diamond interchanges under high heavy vehicle traffic using Synchro traffic simulation software" (2026). Theses. 827.
https://louis.uah.edu/uah-theses/827