Ramp Meters
Updates
Overview
In an effort to alleviate congestion and emphasize motorist safety, the Georgia Department of Transportation continues to implement its ramp metering program. Ultimately, as many as 168 Atlanta-area interstate interchanges are expected to feature ramp meters by 2010.
Background
Ramp meters have been used effectively to reduce traffic congestion in more than 20 cities nationwide for more than 20 years. Recent studies show the effectiveness of ramp meters in reducing congestion, travel times and accidents.
Georgia DOT began implementing ramps meters on Interstate 75 in 1996 and continued the installation on I-75-85 Downtown.
Ramp Meters in Atlanta are necessary due to the increasing congestion in the metropolitan area. Georgia DOT’s 2004-2006 accident data shows approximately 9.5 percent of Atlanta's traffic accidents on I-75, I-85, I-20 and I-285 occurred at entrance ramps. These accidents were, in some way, related to merging onto the freeway.
What Are Ramp Meters?
Ramp Meters are traffic signal devices located on entrance ramps to the interstate. They regulate the frequency of vehicles entering the flow of traffic on a freeway.
Ramp Meters are one of the tools in the toolbox to help mitigate traffic congestion. By pacing the entry of vehicles onto the freeway – usually at 3 to 4 second intervals – the merging vehicles are less likely to slow the freeway traffic. The meters help to:
- Split up the continuous flow of traffic from entrance ramps
- Allow vehicles to merge with freeway traffic more smoothly
- Make travel safer
- Enable the freeway to accommodate more vehicles during peak hour travel
They are utilized during the morning/afternoon peak travel hours, Monday through Friday.
How Do Ramp Meters Work?
- Ramp meters work similarly to traffic signals with a red and green light. All vehicles must stop when the light is red.
- When the signal turns green, the vehicle at the front of the line on the ramp may cautiously move onto the freeway. Only one vehicle is allowed onto the freeway at each green light signal.
- Sensors are located at the top of each ramp to monitor back-ups that may occur on the ramps. If there are too many cars on the ramp, sensors alert the signal which then allow more cars onto the freeway. Operators at Georgia DOT's Transportation Management Center also will monitor the meters through cameras and will make necessary adjustments.
- On two lane ramps, the meters will allow one car to merge at a time.
Part of the Georgia DOT’s Intelligent Transportation System, the meters utilize an advanced camera system to determine the most effective operation of the meters. The ramp meters are controlled at the Georgia DOT’s Transportation Management Center by the NaviGAtor Intelligent Transportation System.
Benefits of Ramp Meters
- Reduce hours of vehicle travel
- Decrease fuel consumption
- Maintain consistent traffic flow on the interstate
- Allow more cars to use the freeway
- Increase freeway speeds
- Reduce some vehicle emissions
- Reduce rear-end and side swipe accidents – accidents associated with merging
Hours of Operation
Below is a schedule of operation for ramp meters in the Atlanta area. Ramp meters are programmed to come on only when the freeway traffic reaches a certain level, so the actual hours of operation may vary somewhat from day to day. Also, if lines on the ramp get too long, the meter may shut off temporarily to allow the traffic to flush out.
I-285 North side
- Eastbound between I-75/Cobb and Peachtree Dunwoody Rd - 6:15 to 10:00 am
- Westbound between Buford Hwy and GA 400 - 6:15 to 10:00 am
- Westbound between GA 400 and I-75 - 1:30 to 7:00 pm
- Eastbound between Roswell Rd and Spaghetti Jct - 1:30 to 7:00 pm
I-285 East side
- Northbound between I-20 and Spaghetti Jct - 6:15 to 10:00 am
- Southbound between Spaghetti Jct and I-20 - 2:00 to 7:00 pm
I-285 West side
- Northbound between I-20 and I-75/Cobb Cloverleaf - 6:15 to 10:00 am
- Southbound between I-75/Cobb Cloverleaf and I-20 - 2:00 to 7:00 pm
I-85 in Gwinnett
(also includes ramps at Chamblee Tucker and North Druid Hills)
- Southbound between Pleasant Hill and N Druid Hills - 6:15 to 10:00 am
- Northbound between N Druid Hills and Indian Trail - 2:30 to 7:00 pm
I-75/85 Downtown Connector
- Southbound between Tenth St and University Ave - 12:15 to 7:00 pm (Tenth St ramp meter also operates 6:30 to 10:00 am
- Northbound between University and Spring St - 6:15 to10:00 am (Fulton St, MLK Jr Dr, JW Dobb and Freedom/Intl also operate 2:30-7:00 pm)
I-75 North inside I-285
- Northbound between Brookwood and Cumberland Blvd- 3:45 to 7:00 pm
- Southbound between Cumberland Blvd and Brookwood - 6:15 to 10:00 am
I-75 in Cobb County
- Southbound between Chastain Rd and Windy Hill - 6:15 to 10:00 am
- Northbound between Windy Hill and Chastain Rd - 2:00 to 7:00 pm
I-75 South side
(Clayton/Henry Co)
- Northbound between SR 138 and Forest Pkwy - 6:15 to 10:00 am
- Southbound between Forest Pkwy and SR 138 - 4:15 to 7:00 pm
I-575 Cobb and Cherokee Co
- Southbound between SR 92 and Barrett Pkwy - 6:15 to 10:00 am
- Northbound between Barrett Pkwy and SR 92 - 3:00 to 7:00 pm
I-285 Southwest side
(Cascade, Camp Creek, etc)
- Southbound between I-20 and Washington Rd - 4:00 to 7:00 pm
- Northbound between Washington Rd and I-20 - 6:15 to 10:00 am. (MLK Jr Dr ramp meter also runs 4:00-7:00 pm)
I-20 West side (Holmes Dr, Lowery, McDaniel, etc)
- Westbound between I-75/85 and Holmes Dr - 3:00 to 7:00 pm
- Eastbound between Holmes Dr and I-75/85 - 6:15 to 10:00 am.
I-20 East side
(Candler, Flat Shoals, Moreland Ave, etc)
- Westbound between I-285 and Boulevard - 6:15 to 10:00 am
- Eastbound between Capitol Ave and I-285 - 3:00 to 7:00 pm.
GA 400 North end
(Old Milton to McFarland)
- Southbound between McFarland and Old Milton - 6:15 to 10:00 am
- Northbound between Old Milton and McFarland - 3:30 to 7:00 pm
US 78 in DeKalb
(North Druid Hills to West Park Place)
- Westbound between West Park Place and Brockett Rd. - 6:30 - 9:15 am
- Eastbound between North Druid Hills Rd. and Hugh Howell Rd. - 4:00 - 6:30 pm
Again, the meters have been programmed to only come on when freeway traffic is dense enough to warrant turning on the meters. Therefore, it is possible that you may encounter a meter that is off during the above hours. If so, proceed down the ramp without stopping. Merge with usual caution.
Ramp Meter Video: Smoothing the Flow