Plans for dual roundabouts on state route 20 continue to proceed forward and are expected to enter the next phase this fall. Right of way acquisition for the project is scheduled to receive authorization to start in October.
The project — located at the intersections of Lawrenceville Street and McGarity Road in McDonough — will construct two roundabouts spaced 596’ apart. A center median will divide the state route between the two roundabouts.
Each roundabout will feature a 140’ inside diameter with a design speed of 20 miles per hour. Truck aprons measuring 17’ in width (access at McGarity Road) and 12.5’ (Lawrenceville Street) will be constructed. Additional truck aprons will be provided for right-hand turning vehicles from either side street to state route 20.
Furthermore, the project will convert Fairview Drive to right-in-right-out access off state route 20. A right-hand turn lane will also be provided.
The project requires additional right of way from thirteen (13) properties. No displacements are expected.
Construction for the project is scheduled to let in November 2021. Roadwork will follow in early 2022 and is estimated to last eighteen months.
Once complete in 2023, morning peak hour delays are expected to decrease by 87% from 155.6 seconds per vehicle to 20.5 sec/veh. Afternoon peak hour delays are estimated to reduce by 84% from 128.6 sec/veh to 20.2 sec/veh.
Other alternatives considered were signalizing the two intersections and constructing left-hand turn lanes on all approaches, or re-aligning Lawrenceville Street to form a T-intersection with SR 20. These alternatives were not selected because they are not expected to provide a significant reduction in delays when compared to the roundabout concept.
The project has total estimated costs of $5.2 million and is funded partially by the city of McDonough. The majority of funds are from Georgia DOT through house bill 170 revenues.
For more information, readers may visit the Georgia DOT website for the project’s concept report.