During both the morning and evening peak time periods, significant traffic congestion occurred at the interchange of interstates 40 and 430, causing delayed—and potentially unsafe—travel for motorists. The Arkansas State Highway and Transportation Department (AHTD) teamed with Garver to develop plans to improve the interchange on a compressed schedule.
Final plans were initially due within six months of the notice to proceed, but adjusted to 10 months when the team combined the project with an adjacent project, which lowered project costs without compromising the number of existing lanes open to traffic.
"Widening any existing bridge can be a challenge due to the issues of fitting new work with the existing bridge, and widening this flyover was more complex due to the curved geometry of the bridge and the construction tolerances of the original construction," said Bridge Team Leader John Ruddell.
In the end, Garver provided design services to AHTD to improve the interchange, replace the Norman Road Overpass, and widen interstates 40 and 430 from four to six lanes within the vicinity of the interchange. Garver provided the design and plans for the roadway, bridges, box culverts, overhead and cantilever sign structures, retaining walls, and right-of-way plans.
"The roadway widening significantly reduced the delay incurred by motorists traveling to the west of the interchange," Project Manager John Cantabery said. "The reduction in congestion results in fewer accidents, and because the design included a new flyover structure, we increased sight distance around the horizontal curve, which improved safety."