Oklahoma Mountain Road Upgrades Tackle Tricky Terrain

The Oklahoma Department of Transportation (ODOT) is working to deliver improvements to SH-10, east of Muskogee, Oklahoma, in a unique segment of roadway that lines United States Army Corps of Engineers (USACE) land at Fort Gruber as well as Braggs Mountain and requires special considerations for both the land stakeholders as well as the terrain. Freese and Nichols has been hired to provide roadway design and geotechnical services, which include slope stability analysis and potentially slope stability design, for the corridor widening project along a 2-mile stretch of highway. The addition of safety shoulders will add space for approaching traffic and a sense of comfort for drivers who might otherwise feel as though they are directly on the steep edges of the mountainside.

Knowing that strong communication will contribute greatly to the success of the project, our firm has assembled a team of experts who are well-versed in these types of adverse conditions and begun early engagement activities and coordination meetings with the governmental stakeholders. Freese and Nichols environmental experts have been able to minimize and accurately depict the National Environmental Policy Act (NEPA) study area boundary and coordinate with USACE to allow our sub-consultants access to the property to perform data collection.

As a result of the project site being along the side of a mountain, the roadway contains many twists, turns and steep grades – a portion of the road drops over 310 feet in less than one and a half miles! Given this demanding terrain, the team has identified solutions to the widening challenge through recommendations for horizontal alignment adjustments to pull the roadway curvature into the mountain where grades are steepest, and to further mitigate the downgrade challenges through asymmetric widening and lateral crown adjustments.

Because the roadway curvature is being adjusted “into” the mountain and widened at the shoulders within an unstable rocky terrain, it was paramount that our team of geotechnical experts evaluate the corridor for global stability and other underlying concerns.

We are proud to work with ODOT to provide a product that not only fits their current needs, but also continues to serve local and regional traffic for years into the future.


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