Diverging Diamond Interchanges – A Decade of Lessons Learned

Diverging Diamond Interchanges, or DDIs, are a relatively new interchange that has greatly expanded in prominence over the past fifteen years.  The first DDI in the US opened in 2008 and opened with little fanfare though it would draw hundreds of visiting engineers to tour it in the years after its opening.  This presenter was involved in the post evaluation of that interchange kicking off almost a decade and a half of working on DDIs around the world.  This presentation utilizes over ten years of case studies of DDI projects spanning the globe and will highlight lessons learned that span geometric design, traffic operations and analysis, public outreach and education, and maintenance.  All of the case studies will involve firsthand experience and involvement and provide insight into design and operational issues that have changed the way subsequent projects have been developed.  Case studies will span projects from conceptual development and alternatives analysis to final design to construction and operation.  The lessons learned will specifically highlight elements that can be easily overlooked that have direct safety and operational impacts.  The presentation will also include elements and issues that need to be taken into account on future projects as well as post-implementation comparisons.

Summary

This presentation utilizes over ten years of case studies of Diverging Diamond Interchange projects spanning the globe and will highlight lessons learned that span geometric design, traffic operations and analysis, public outreach and education, and maintenance.

Bio

Mr. Siromaskul‘s DDI experience includes approximately 100 different project sites with over 40 projects carried into the design process, half of which are open to traffic, including the smallest DDI in the world in Cheyenne, WY, and the largest DDI in the world in Sarasota, FL.