Final Design for Highway Expansion and Corridor Connectivity
The TH 169 Cross Range Expressway project included final design for a 1.55-mile expansion from two lanes to four lanes, located east of Taconite in Itasca County. The work also realigned approximately 1,000 feet of CSAH 15, 400 feet of CSAH 7, and 200 feet of the Mesabi Bike Trail, along with updates to nearby entrances and road connections. This effort completes the Segment 2 connection originally started in 2007. Corridors of Commerce funding enabled MnDOT to deliver the remaining segment.
Engineering Solutions for Challenging Conditions
SRF addressed a range of design challenges, including:
- Managing impervious runoff near wetlands and high groundwater
- Maintaining traffic on CSAH 15 and CSAH 7 where detours were not feasible
- Coordinating with an active gravel pit operation adjacent to the new roadway
The gravel pit access also neighbored an abandoned municipal waste site, requiring construction plans to include potential hazardous materials management and disposal procedures.
Roadway Design and Drainage Considerations
SRF completed the final design for the 1.9-mile reconstruction, expanding the roadway to a four-lane divided highway before tapering back to a two-lane section. The design addressed high groundwater, ensured safe sight distances, and preserved operational access to CSAH 7, CSAH 15, and a nearby gravel pit. Subsurface drainage was included to manage runoff from the center median to exterior roadway ditches.
Updated Signing and Striping Plans
As part of the final design, SRF developed new signing plans to meet updated retroreflectivity standards and MnDOT requirements. All pavement markings were designed to align with current MnDOT striping guidelines.
Resource Links:
Corridors of Commerce – MnDOT
Internal Category:
Roadway Design
Traffic & Technology
Water & Environment
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