Cobb County, Georgia’s Lower Roswell Road was experiencing safety issues: several locations saw frequent crashes, there were no bike lanes for the corridor’s many riders and stormwater didn’t drain properly. As part of a Special Purpose Local Option Sales Tax (SPLOST) program, the Cobb County Department of Transportation (DOT) called on Gresham Smith to develop safety and operations upgrades to a nearly 3-mile section of the road. After analyzing traffic at numerous intersections, our team designed and implemented a variety of cost-effective, sustainable solutions. Benefiting motorists, pedestrians and bicyclists alike, upgrades to Lower Roswell Road have received positive feedback from the community, offering residents a safe and inviting new streetscape.


Cobb County Department of Transportation


Cobb County, GA

Project Type

Transportation, Water






mile stretch of roadway


foot wide multi-use trail


foot diameter roundabout

Collecting Community Input

Collecting Community Input

After conducting our own traffic analysis we asked community members for their thoughts. Based on the feedback we received, our team modified the conceptual design. The result? A roadway that not only enhances operational efficiency and addresses safety concerns, but also minimizes impacts to the corridor and achieves a context-sensitive solution.
A Variety of Design Recommendations

A Variety of Design Recommendations

Our revised design recommended a variety of elements, including alternate turn-lane lengths and traffic signal operations. We also proposed additional turn lanes, curbs and gutters, drainage improvements, 4-foot bikes lanes on both sides of the roadway, a 5-foot sidewalk on the north side and an 8-foot recreational trail on the south side.
Enhanced Safety in a Roundabout Way

Enhanced Safety in a Roundabout Way

Based on community input, we designed a roundabout intersection at the eastern end of the road. The three-legged, 115-foot diameter roundabout channels traffic around a center island, making for smoother and safer traffic flow. The roundabout also reduces congestion, eliminates the need for traffic signals and will ultimately decrease operating and maintenance costs in the long run.
A Multimarket Approach

A Multimarket Approach

In addition to roadway improvements, our Water + Environment team replaced water distribution and sanitary sewer lines impacted by the project, including an existing cement water line along approximately 15,000 linear feet of the roadway.
A Sustainable Solution

A Sustainable Solution

Gresham Smith incorporated numerous sustainable features into the design. For example, into order to retail the upscale, wooded character of the existing corridor, our team went to great lengths to reduce the project’s footprint against nearby residential and wooded areas.

The project was evaluated using the new Cobb County DOT PEACH (Preserving Environment And Community Heritage) Roads—a transportation environmental ratings program that recognizes cost-effective, sustainable practices in transportation projects—and was the first project reviewed using this criteria to score Gold Certification.


Project Contact

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Jody Braswell P.E.
Jody Braswell P.E.
State Transportation Leader - Georgia