Bob Gray Road Roundabouts | Knox County, TN

Roundabouts are not commonplace in our area; however, they can significantly enhance the quality of life for concerned residents who live on and along congested roadways. They make roadways safer, reduce commute times and relieve a significant amount of traffic congestion.

In September of 2009, Knox County Engineering and Public Works contracted with Cannon & Cannon, Inc. (CCI) to conduct a detailed feasibility study to identify the most appropriate design solutions and address safety and congestion issues for two intersections on Bob Gray Road: Bob Gray Road/Mabry Hood Road and Bob Gray Road/Bob Kirby Road.

The study looked at several alternative solutions, but our final recommendation was that the construction of two modern roundabouts would be the most effective way to address the needs of both intersections. In 2011, Cannon & Cannon was contracted again by Knox County to develop design plans for the two intersections.

During the development phase of the project, two public hearings were held to inform the affected community of the proposed design. This resulted in significant and extremely vocal opposition, which led to several follow-up meetings with concerned citizens and interested local politicians. In the end, Knox County officials approved the project in October 2012 allowing construction to begin.

The final design was quite challenging as extremely steep approach grades and the presence of nearby houses and other constraints made full satisfaction of all design criteria difficult to achieve. Some compromises were made, including a smaller than typical overall roundabout size (inscribed circle) and the use of an innovative mountable island design to allow the occasional large truck to drive over splitter islands.

In addition, the project required a large retaining wall at one location, and needed to be completed during a short summer period. This was accomplished in order to minimize the impact on school traffic, as five schools are located in the vicinity of these intersections.

Citizen feedback has been extremely positive and it is anticipated that crashes will be significantly reduced. Here is one citizen’s comment that provides a good summary of how these roundabouts are performing: “I was one of the skeptics, but these roundabouts are unbelievable. They work and they are attractive. Your design is spot-on and I haven’t heard a single complaint.”

We are extremely pleased to work with the community and client to find the best solution for the safety and congestion issues experienced on Bob Gray Road.