In Fort Wayne, Indiana, a traditional diamond interchange at I-69/DuPont Road was congested, motorists were delayed, and the situation was expected to get worse due to ongoing commercial and residential development. To increase capacity and relieve traffic congestion, the I-69/DuPont Road interchange was reshaped into a Diverging Diamond Interchange (DDI).
Opened in 2014, the I-69/DuPont Road DDI was the first DDI in the state. This innovative interchange is a lower cost transportation solution that adds traffic capacity to support area development. With two hospitals located in close proximity – one on either side of the interstate – the revamped interchange also improves access for emergency vehicles.
Designed by Burgess & Niple (B&N) for the Indiana Department of Transportation (INDOT), the DDI serves an estimated 40,000 motorists each day. Compared to the three other interchange alternatives evaluated, building a DDI at this location was the lowest cost option that provided the most traffic capacity without widening the existing bridge over I-69.
B&N provided:
- Roadway and bridge design
- Traffic capacity and operations analysis
- Traffic signal, sign and lighting design
- Public outreach and education
- Topographical survey
Improved Connectivity for Pedestrians and Bicyclists
A barrier separated median was designed for pedestrians and bicyclists to provide a safer path through the I-69/DuPont Road interchange. The path runs the entire length of the project and connects to an existing network of trails.
Construction Phasing and Maintenance of Traffic
The project was built within six months by phasing construction to build half the project at a time. The roadway was accessible throughout construction with the exception of two weekend closings of the bridge over the interstate. Maintenance of Traffic was an important aspect of the plans, due to the large number of nearby businesses and hospitals.
Public Outreach and 3D Traffic Models
Because this was the first DDI in Indiana and a new concept for motorists, driver education and public outreach were important aspects of the project. B&N developed advanced 3D traffic models and drive-through simulation animation to help citizens understand how to navigate a DDI.
The I-69/DuPont Road DDI added capacity and relieved congestion in a growing area of Fort Wayne. Emergency vehicles have better access to two hospitals. Bicyclists and pedestrians have improved connectivity and a safer way to travel the interchange, thanks to a unique barrier separated multi-use path.
First in State, Best in State
Upon completion, the DDI received two Best in State engineering awards. The American Council of Engineering Companies (ACEC) of Indiana presented the project with the 2016 Grand Project Award. It also received the Civil Engineering Project of the Year Award 2015 from the American Society of Civil Engineers (ASCE) Indiana Section.