East Belgrade I-90 Interchange
Belgrade, Montana
Award: Grand Prize – 2016 ACEC Montana Engineering Excellence Award
Throughout the last several decades, the City of Belgrade, Montana, and Gallatin County have experienced significant population growth. This influx caused traffic congestion in the heart of Belgrade at the four-way stop intersection and the westbound off-ramp was reaching the saturation point. Emergency service providers were frequently blocked by trains as there were no grade-separated crossings in Belgrade.
Increased traffic was not the only issue facing local leaders; there had been strong growth at Bozeman Yellowstone International Airport (BYIA) since the mid-1970s. BYIA enplaned 500,011 passengers in 2015 and was named the ninth busiest airport in the northwest mountain region.
Morrison-Maierle prepared a study that evaluated future traffic conditions and intersection operations, and identified alternative interchange configurations.
Working with the Montana Department of Transportation (MDT) staff, Morrison-Maierle and its multi-disciplinary team of designers proposed a $16.4 million compressed diamond (dog-bone) interchange that included a new crossroad and connections, reconstruction of old Highway 10, two interstate bridges, a railroad shoofly and underpass structure, two-lane roundabouts at the proposed interchange ramp terminals, intersection signalization and street lighting, and extensive storm drainage improvements. In addition, improvements to the access roadways at BYIA were carefully coordinated between the two owners—MDT and the Gallatin Airport Authority. Balancing two projects at once, Morrison-Maierle used an accelerated design development plan for this project.