Blount County, AL
CLIENT: ALDOT
PARTNER: Blount County
Sain Associates completed the design process for a three-series roundabout at the intersections of SR-160, US-31, and I-65 near Hayden, Alabama. The client for this project was ALDOT East Central Region, and we partnered with Blount County throughout the design process. The roundabout series provides much-needed safety improvements to an interchange that has experienced wrong-way movements onto the interstate. The project’s overall goal was to solve the wrong-way maneuvers issue and increase the interchange’s performance. The initial wrong-way study began in 2014, and design work started in 2018.
In the project’s concept development and alternative analysis phase, roundabouts at each of the interstate ramps, also known as a dogbone interchange, were determined to provide the greatest safety improvement while improving traffic operations. Due to the proximity of the US-31 intersection to the northbound ramps, a third partial cloverleaf interchange was designed. Other unique attributes of this project included access to multiple gas stations along these interchanges and Park and Ride access locations.
The biggest challenge faced in plan development is that the roundabout series is irregular and non-linear, so a traditional set of roadway plans does not translate directly. During construction, ALDOT opted for a temporary closure of US-31 and an incentivized detour period. Another challenge included obtaining the right-of-way from nearby parcels and easements to reconstruct driveways connecting to the gas stations.