The highly traveled Exit 187/Hogan Road crossing on I-95 in Bangor is one of the busiest diamond interchanges in Maine and serves as an important connection point for regional and local travelers. However this portion of the roadway is characterized by safety concerns, heavy congestion, and lack of adequate bicycle and pedestrian access. Recognizing the need to address these issues and provide safer transportation for all users, the Maine Department of Transportation (MaineDOT) decided to implement a Diverging Diamond Interchange (DDI) at this location.
To support MaineDOT, VHB provided traffic simulations and visualizations for public presentation that demonstrated how a DDI utilizes signalized crossover intersections with two-phase signals to move arterial street traffic to the opposite side between ramps, enabling direct access to ramps without crossing opposing traffic. This design enhances flow and safety, making it particularly effective at busy interchanges. The adoption of this approach can increase capacity, reduce delay, and improve overall coordination with nearby signals, while also offering significant safety benefits, including fewer conflicts, reduced emissions, and improved pedestrian safety.
VHB has been an integral part of the preliminary engineering with ongoing highway and traffic design components including horizontal and vertical alignments; intersection grading; street and pedestrian lighting; ramps; traffic signals; construction phasing; drainage; shared-use path; retaining walls; and ADA compliance. VHB was recently selected by MaineDOT to complete the final design for not only the interchange ramps and roadways but also the bridge component of the Bangor DDI project as well. Construction is anticipated to begin in spring of 2025.
VHB is proud to support MaineDOT on this innovative effort—the first of its kind for MaineDOT—and contributing to the enhanced safety and long-term well-being of the local community.
