McDONOUGH — Plans for dual roundabouts on Ga. Highway 20 are expected to enter the next phase this fall, with right of way acquisition scheduled to begin in October.
The project — located at the intersections of Lawrenceville Street and McGarity Road in McDonough — includes construction of two roundabouts spaced 596 feet apart. A center median will divide Ga. Highway 20 between the two roundabouts.
Each roundabout will feature a 140-foot inside diameter with a design speed of 20 mph. Truck aprons measuring 17 feet in width (access at McGarity Road) and 12.5 feet (Lawrenceville Street) will be constructed. Additional truck aprons will be provided for right-hand turning vehicles from either side street to Ga. Highway 20.
Furthermore, the project will convert Fairview Drive to right-in-right-out access off Ga. Highway 20. A right-hand turn lane will also be provided.
The project requires additional right of way from 13. No displacements are expected.
Construction for the project is scheduled to let in November 2021. Roadwork will follow in early 2022 and is expected to last 18 months.
Once complete in 2023, morning peak hour delays are expected to decrease by 87% from 155.6 seconds per vehicle to 20.5 seconds per vehicle. Afternoon peak hour delays are estimated to reduce by 84% from 128.6 seconds per vehicle to 20.2 seconds per vehicle.
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 Ga. Highway 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 cost of $5.2 million and is funded partially by the city of McDonough with the majority of funding coming from the Georgia Department of Transportation.
For more information, visit the Georgia DOT website for the project’s concept report.