Enhancing Safety and Accessibility: Highway 87 in Frazee, MN

Challenge

Trunk Highway 87 (TH87), which runs through the heart of Frazee, Minnesota, serves as a crucial link for the town's 1,300 residents, connecting them to U.S. Highway 10.  

Passing Frazee Senior High School and accommodating heavy traffic volumes, this 30-mile corridor required surface reconstruction and preservation, box culvert replacements, improved safety and ADA accessibility, and drainage system upgrades. 

An unexpected challenge arose during the rural project's design phase. While conducting delicate soil borings to assess existing conditions near the Toad River Bridge, a Minnesota Department of Transportation (MnDOT) drill crew inadvertently punctured an artesian aquifer. Instead of abandoning the drill, it was removed, causing groundwater to erupt.

Solution

In a collaborative effort with MnDOT District 4, SEH led the TH 87 project team. The project comprised two distinct components: a 27.2-mile rural shoulder widening and pavement rehabilitation, and a 2.4-mile project that included 0.6 miles of rural mill and overlay and 1.8 miles of urban reconstruction. SEH was responsible for the final design work for both segments, including highway design, lighting, traffic, natural resources, permitting, water resources, structures, geotechnical engineering, and planning services.

Key elements of the project included: 

• Typical highway design, railroad coordination, bridge replacement, approach panel replacement, guardrail replacement, and box culvert bridge replacement. The SEH lighting group collaborated with the City to assess multiple design alternatives, ultimately leading to the development of the final lighting system.
• The natural resources group delineated the approximately 30-mile corridor frequently bordered by wetlands. The team also partnered with the Army Corps of Engineers to devise mitigation alternatives to meet project requirements.
• The water resources group was responsible for designing approximately 130 culverts for the rural portion of the project and nearly a mile of storm sewer for the urban section.
• The structures group tackled the design of two retaining walls and evaluated the stability of a third wall and several downtown buildings to determine if there was a risk of damage during construction.

The punctured artesian aquifer incident raised concerns about potential aquifer-level depletion and necessitated involvement from the Minnesota Department of Health and the Minnesota Department of Natural Resources. As a result, SEH worked to develop alternatives to remedy the artesian conditions quickly. The team created a Stream Diversion Plan to replace the existing box culvert, which involved a mix of earthen levee and sheet pile. Particular attention was given to the 20 ft. proposed depth of the sheet pile to ensure it did not puncture the clay layer.  

Safety was at the forefront of project design, particularly in critical areas like pedestrian crossings near the causeway and the school. These improvements included relocating crossings and adding Rectangular Rapid Flashing Beacons (RRFBs), all contributing to a safer environment. Signal modifications, warning signs, and incorporating a pedestrian maze were implemented to establish the railroad crossing as a Quiet Zone. 

To promote multimodal use and enhance accessibility for pedestrians, cyclists, and other non-motorized traffic, a shared-use path was constructed along the west side of TH 87. To accommodate this, the team slightly realigned the center line.  

All intersections and sidewalks along the corridor were upgraded to meet ADA compliance standards. Features such as ramps and truncated domes were introduced to ensure accessibility for individuals with disabilities. 

Now constructed, TH 87 meets MnDOT and the City's objectives by prolonging the road's lifespan, improving safety at crossings and connections, and enriching Frazee's character with aesthetically pleasing and practical features.      

Awards

• 2024 Honor Award | American Council of Engineering Companies, Minnesota Chapter (ACEC-MN)