141 / State Bridge Rd Reconfiguration Concepts141 / State Bridge Rd Reconfiguration Concepts. The City Hired Parsons Brinckerhoff for $38k to compile the following presentation of 2 concepts.
The First Concept is the ThrU Intersection. It eliminates Left Turns from the intersection and creates a U-Turn in the Median, for cars to make a right and then U-turn to go instead of a traditional Left.
This will have cars enter the intersection twice.
For example: Cars driving from St Ives/Medlock Bridge Subdivision want to go to Target. They will need to make a right at State Bridge, going West. Then make a U-Turn by Pikes and drive straight through the intersection to enter.
Another example is the commuters driving North on 141 and need to go West on State Bridge Rd.
Currently there is 2 Left Turn lanes (700 feet, 350 feet in length).
The proposed U-Turn lane would be a Single of 350 feet in length. Also an additional light would be needed for the westbound traffic to stop to allow for the U-Turns.
Logistically, U-Turns are slower to maneuver than Left Turns. They are also more challenging for buses, trucks and emergency vehicles.
This concept is proposing a Marginal 12-13% improvement in Capacity.
The Wide Ranged Cost is $2-4million.
The 2nd Concept Integrated a Continuous Flow Intersection with the ThrU Turn.
The proposed capacity improvement for this was even less at 4-6%.
Below shows the Comparison and percentages.
This study does not address projected population growth within Johns Creek & rapid development in Forsyth County, as well as estimated delay when the proposed intersection reaches capacity and beyond.
It seems an unusual process for the City Council to adopt options and submit to GDOT, and then have the public involvement process last.
It would behoove the City to involve the Public first, before moving forward with the plans.
Updated with additional wording in Red.
Source: City of Johns Creek
Signage Photos: Virginia DOT