Highway 463 and I-55

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Madison County, Mississippi

Project Owner:

Department of Transportation


Contract Amount:


"Steel was selected for this highway interchange in Mississippi because it could accomodate the curved design and could be erected with minimal disruption to traffic. Its curved girders are recordbreaking and its geometry mindboggling. But despite being a structural engineering feat, Madison, Mississippi’s Single Point Urban Interchange (SPUI) blends gently into its suburban environment and unobtrusively handles what was once a choking burden of traffic. While drivers may not notice the unusual design of the structure linking Interstate 55 and Mississippi Route 463, its shape makes it a distinctive landmark from the air. Due to its configuration of lanes and ramps toward a central bank of traffic signals, the Single Point Urban Interchange, or SPUI (pronounced “spew-ee”), is shaped much like a bow tie: narrow at the middle and wider at the abutments. The challenge for the project team was to create that bow tie from steel." – Ming F. Chang, P.E. and Harry Lee James, P.E. Read the full article.