Skip to main content

Pennington CSAH 8 New South Side Corridor

Photo of new bridge crossing
Pennington CSAH 8 New South Side Corridor

Location:  Thief River Falls, MN
Client:  Pennington County Highway Department


The growth of Thief River Falls is expected to increase along the southern boundaries in the coming years with the expansion of businesses and entities like the Sanford Medical Center, the Thief River Falls Airport, Challenger Elementary School, Digi-Key, and Arctic Cat, all of which are critical facilities to the city’s economy. 

However, east-to-west connectivity within this area is limited, restricting efficient access to this southerly growth. New and updated corridors for increased traffic types and volumes needed to be evaluated to allow the city to continue to thrive for years to come.

The Project

HEI assisted the Pennington County Highway Department in providing conceptual studies, roadway/bridge design and construction documents, public engagement, environmental permitting, and construction assistance for the new corridor including a new river crossing, roadway, and intersection improvements. 

Completed roundabout
The new roundabout and corridor improvements enhance traffic flow, safety, and connectivity within the growing areas of Thief River Falls, MN. 

HEI also teamed with a partner to bring our complementary qualifications and experience together to best serve the community. Through this partnership, two build alternatives and a no-build alternative were evaluated and scored. HEI kept in mind the needs for the project, including efficient access for business and residential expansion. Our team recommended a build alternative creating a new river crossing and street corridor allowing for businesses and residential growth for these areas.

HEI and its partners developed a project that included the construction of a new 1-mile street corridor, a new bridge, and two new roundabouts, each at major intersections. Construction was completed and the facilities were fully operational by the fall of 2020. 
Before and after comparison of the corridor
A before and after comparison view of the new CSAH 8 south corridor with a multi-use path.

This project completed the last gap in the TH 59 truck route corridor through the City of Thief River Falls to accommodate truck traffic. The completed corridor provides an alternative route for TH 59 through traffic as well as trucks associated with industries on the west end of the city, such as Digi-Key and Arctic Cat. It also provides significantly improved shipping access from the industrial development to the municipal airport.

Safety was also improved along this corridor with the new roundabouts on major CASH and TH intersections, ADA-compliant pedestrian facilities connecting a multi-use path network, and street lighting throughout. Several elements of the project also included unique aesthetic features. 

Pennington new bridge
Completed new bridgeThe completed new bridge crossing features decorative architectural features along with the picturesque view of the Red Lake River. 

One of the unique features of this project is that due to the subtle curves of the new approach alignment of CSAH 8, eastbound traffic gets a picturesque view of the architectural features of the new bridge on the west side of the Red Lake River. These features include decorative pilaster monuments at the piers, separate pile-founded pilasters and retaining walls to tie into the wingwalls at the bridge ends, pre-cast concrete caps on all pilasters to accommodate the bridge lighting, and a unique arched ornamental railing

The design and construction of the bridge was completed with a restricted timeline due to flooding in the area. Thanks to the efforts of everyone involved, this project met its major milestones and was substantially completed and open to traffic on time with only minor maintenance and cleanup items taking place after that. 

Through this project, the Pennington County Highway Department was able to accommodate industrial truck traffic around downtown Thief River Falls and save residents nearly 3 miles of travel distance to key destinations like the Sanford Health Medical Center and Challenger elementary school.

Before and after of the west roundabout
A before and after comparison of the new roundabout connecting TH 32 and CSAH 16.


Client Benefits

  • Improved access for all major businesses to the airport and improved emergency access to Sanford Medical Center.
  • Provided necessary transportation infrastructure for future growth and development consistent with the City’s comprehensive plan.
  • Improved quality of life for residents on existing east-to-west routes by redistributing high traffic volumes in the southern limits of the city.
  • Improved opportunities for non-motorized travel through expanded City trail networks.
  • Completed truck alternative route avoiding downtown local traffic and improving safety and shipping efficiency.

Ribbon cutting bridge dedication event held in July 2021. The Pennington County Highway Department hosted a bridge dedication/ribbon-cutting ceremony in July 2021. 

Project Awards

The Minnesota County Engineers Association recognized this project with the 2021 Project of the Year Award. Read our full announcement to learn more. 

The American Council of Engineering Companies of Minnesota (ACEC/MN) recognized this project with the 2022 Engineering Excellence Honor Award. Read our full announcement to learn more.