Upon completion of the review, MTJ developed two sketch-level concept alternatives. Key to the designs was addressing the higher speed context to optimize safety and operations.

The resulting concept of horizontal geometric design was predicated on the application of traffic/highway engineering and modern roundabout design principles and criteria working together to optimize safety for this high-speed rural application.

Working with the project team, the final MTJ design ensured adherence to foundational safety design principles for safety, while maintaining acceptable impacts with respect to ROW, grades, and impacts on surrounding land uses.

MTJ provided a peer review for this challenging high-speed rural application roundabout. The peer review involved a review of initial concept designs by others, followed by the development of corrective and optimized geometrics that reduced impacts and improved safety and access to adjacent parcels.

To address the skewed intersection and to minimize ROW impacts, we implemented a non-circular 147’ x 127’ ICD. The size, shape, and placement were determined after exploring multiple placements and sizes that addressed the skewed alignment, but each of these resulted in greater ROW impacts.

MTJ Roundabout Engineering, working directly with the WIDOT SW Region Project Development group under a master contract, provided the Department with roundabout design services. These included horizontal geometric design, review of vertical design, signing, markings, and landscape design, access alternatives analysis, public outreach services, and construction field layout to reconstruct this intersection.