Beginning Wednesday, commuters in South Forsyth will notice that the new meters on the entrance ramps on GA 400 at McFarland Parkway (Exit 12) will be activated.
The ramp meters will be turned on before rush hour and operate at different times of the day depending on traffic patterns, according to the Georgia Department of Transportation. Every 3-5 seconds, a cycle from red to green allows one vehicle at a time to merge onto GA 400. On two-lane ramps, the left and right lanes have alternating lights, so the left lane goes while the right is stopped, and vice versa.
“We’ll monitor these new ramp meters very carefully. If traffic starts to back up on the ramp, sensors will speed up the meters to allow more vehicles to move through, said Georgia DOT Traffic Engineer Scott Zehngraff. "If our cameras show traffic spilling out onto the surface streets, we can turn them off completely."
GDOT says ramp meters are intended to reduce average rush-hour commute times. The meters are placed on entrance ramps to help control the flow of traffic from the surface streets onto the interstate or state route. Without metering, vehicles push their way all at once onto the highway in a disorderly and potentially dangerous manner. Once these vehicles reach the merge point, they force their way into the travel lanes, causing additional congestion due to stop-and-go merging activity. When this happens on already traffic-heavy roadways, there is a total breakdown of free-flow near the on-ramps, which has a ripple effect on traffic for many miles. Even with no stalls or accidents, heavy on-ramp traffic causes congestion that both extends and continues throughout the rush hour.
To date, here are 170 ramp meters that are operational in the metro Atlanta area. Other benefits include reductions in fuel consumption, merging accidents, and vehicle emissions.
“There will be a short learning curve period in the first few days as motorists adjust to following the meters, said Zehngraff. "We realize that we may need to tweak them. Please bear with us, and keep in mind that there is no one ‘silver bullet’ solution to eliminate congestion. Ramp meters are just one of several tools that can help fight congestion.”