The population in Boone County, Kentucky, more than doubled over the last three decades and the steady growth isn’t stopping anytime soon. Located at the convergence of three major interstate systems and home to the Greater Cincinnati-Northern Kentucky International Airport, it’s easy to see why. However, the influx of residents has led to an increase in vehicular and non-vehicular traffic, and KY 237 – a major roadway that serves as Boone County’s spine and connects neighborhoods and businesses – needed improvements to keep up.

The Kentucky Transportation Cabinet called on Gresham Smith to transform a 5.2-mile stretch of the curvy, two-lane roadway into an efficient corridor that reduces congestion, reconnects neighborhoods and accommodates alternative modes of transportation. Using a multi-lane roundabout, a single-point urban interchange and a multi-use path, our design team delivered a modern roadway that meets the needs of the growing Boone County community.


Kentucky Transportation Cabinet District 6


Burlington, Kentucky

Project Type





Showcase, APWA Kentucky Chapter 2017 Project of the Year


reduction in traffic accidents


under budget


mile section

Taking the Process to the People

Taking the Process to the People

From the outset, Gresham Smith not only shared project information and design options with our client, but also with the people who live, work and play along the KY 237 corridor. Each of our public meetings had more than 300 attendees and one-on-one conversations with property owners helped us establish priorities for the roadway project.
A Win-Win Solution

A Win-Win Solution

The project began on the south end of the corridor, which is bordered by Gunpowder Creek on one side and a church on the other. Our design solution called for widening the existing roadway to five lanes and adding multi-use paths on both sides, which meant either the creek or the church would be affected. However, after much coordination Gresham Smith recommended a retaining wall along the multi-use path and limited the impact to the church’s property.
A Single Point Solution

A Single Point Solution

The second phase of the project addressed the intersection of KY 237 and KY 18. Traffic data initially indicated that KY 237 needed three left turn lanes onto KY 18 to accommodate turning vehicles, however we ultimately recommended a single point urban interchange (SPUI) instead. By bringing all turning traffic to one elevated signalized intersection and allowing non-turning traffic to flow freely below, we limited the number of light cycles drivers sit through, freed up surrounding land and accommodated future traffic projections.

One Roundabout, Multiple Benefits

The final phase of the project included a new bridge over Gunpowder Creek and a multi-lane roundabout at the intersection of KY 237 and Camp Ernst Road. We initially considered adding dual left turn lanes at the existing “T” intersection, but later decided that a multi-lane roundabout would not only improve traffic flow and safety, but also be less expensive than a signalized intersection.
Dollars and Sense

Dollars and Sense

By using creative design solutions our team was able to save approximately $4.4 million, approximately 10% of the client’s $40 million construction budget. Some of our cost-saving solutions can be attributed to replacing the design’s bike lane and sidewalk with a multi-use path, using a roundabout instead of a conventional intersection and reducing the pavement from five lanes to four near Gunpowder Creek.
Connecting the Dots

Connecting the Dots

The Gresham Smith project team went the extra mile to support community connectivity. The project provides a safer route to the local middle school, adds multi-modal access to Boone Woods Park and increases accessibility for nearby businesses. The new SPUI, multi-use path and forthcoming roundabout strengthen the backbone of Boone County and will support the growing community for years to come.


“Gresham Smith demonstrated great flexibility and responsiveness. [They] found opportunities to recommend design changes that offered the possibility of preserving ever shrinking construction dollars. Most importantly, the quality of design always maintained a focus on safety for the driving public.”

Carol Callan-Ramler, KYTC, KYTC



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Dave Stills, P.E.
Dave Stills, P.E.
Senior Transportation Engineer