East Belgrade Interchange
Two Projects in One
Throughout the last several decades, the City of Belgrade, Montana, and Gallatin County have experienced significant population growth. In addition to a myriad of other concerns, the influx in population was causing traffic congestion in the heart of Belgrade at the four-way stop intersection of Broadway and Main Street. And at the community’s only interchange, the westbound I-90 off-ramp at Jackrabbit Lane was reaching the saturation point. Emergency service providers were frequently blocked by trains as there were no grade-separated crossings in Belgrade. In the late 1970s, local planners began to consider the need to increase access to the interstate and improve access to the airport.
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 when a connection from the airport directly to the interstate was first mentioned in the 1976 Airport Master Plan. Passenger numbers had doubled since 2011, with a 46% increase in the last five years alone. BYIA enplaned 500,011 passengers for the 12-month period ending August 31, 2015, and became the ninth busiest airport in the northwest mountain region.
Tackling the traffic issues within Belgrade and the growing enplanements for BYIA resulted in a project that focused on the efforts of the Montana Department of Transportation (MDT) and BYIA for the betterment of a multi-modal corridor located on the east edge of Belgrade.
Services & Highlights
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Professional engineering services to help identify interchange alternatives for environmental review
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Interchange engineering design
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Airport engineering services
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Engineering services for right-of-way and utility relocations
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Solved two major infrastructure problems with one project
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Roundabout design
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Design that allowed for “top down” construction of two interstate bridges
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Construction management
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Continuous flow intersection configuration to guide drivers to the airport terminal
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Irrigation ditch design and coordination with six separate private and public shareholders
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Funding obtained through a TIGER grant
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Coordination of local, state, and federal agencies
To understand the extent of the challenges, Morrison-Maierle prepared an engineering operational analysis for the proposed I-90 interchange on the east side of Belgrade near BYIA. During the study, Morrison-Maierle evaluated future traffic conditions and intersection operations and identified and evaluated alternative interchange configurations for environmental review.
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, complementary 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. The BYIA roadway modifications were sequenced to provide a paved detour to the airport while the interchange project and new main entrance to the airport were being constructed. Upon completion, a major component of the area’s transportation master plan is now in place. Specifically, a new point of access to the interstate system, secured through the Federal Highway Administration (FHWA), is in place, and Dry Creek Road (S-290) is now rerouted, diverting some of the through traffic away from Belgrade’s downtown through the airport to the new interchange.
Adding to the complexity, Morrison-Maierle worked with several stakeholders and funding sources. In addition to MDT, the Federal Highway Administration, Federal Aviation Administration, Gallatin County, the City of Belgrade, the Gallatin Airport Authority, Montana Rail Link, and several community members and groups spent months working to make this project possible. Funding for the project came from a wide variety of resources including Montana’s Federal Aid funds, two congressional earmarks, a USDOT 2012 Transportation Investment Generating Economic Recovery (TIGER) discretionary grant, and significant local agency funds.
Large public works projects are normally a single-agency undertaking. These projects could not have been completed without the joint efforts of the local, State, and Federal partners working to complete the East Belgrade Interchange and the roadways at Bozeman’s airport, which together provide a major link in Belgrade’s transportation system.
Related Projects
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Custer Avenue Interchange
The Custer Interchange and accompanying interstate and area street improvements stand as the single largest urban highway and bridge construction project in MDT's history.
North Sheridan Interchange
The North Sheridan Interchange (NSI) project included reconstructing and relocating the interchange and improving I-90 and the city’s major north-south access road, North Main Street.
