1 / 29

GDOT’s Metro Atlanta Ramp Meters

GDOT’s Metro Atlanta Ramp Meters. Marc Plotkin Traffic Engineer II :Regional Traffic Operations. Topics. What, and Why Safety Benefits Design Considerations History in Atlanta Implementation Operations Results and Findings. What Are Ramp Meters.

brock-meyer
Download Presentation

GDOT’s Metro Atlanta Ramp Meters

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GDOT’s Metro AtlantaRamp Meters Marc Plotkin Traffic Engineer II :Regional Traffic Operations

  2. Topics • What, and Why • Safety • Benefits • Design Considerations • History in Atlanta • Implementation • Operations • Results and Findings

  3. What Are Ramp Meters • Part of NaviGAtor, Georgia DOT’s Intelligent Transportation System (ITS) • “Traffic lights” on interstate entrance ramps designed to control traffic flow onto the interstate • Proven to relieve traffic congestion in over 20 U.S. cities for over 20 years

  4. Ramp Meter Locations

  5. Why? • Reduces crashes at merge points • Increases freeway productivity • Reduces stop-and-go traffic • Reduces fuel consumption • Cost-effective traffic management tool • Improves trip predictability

  6. Safety Analysis Minnesota • Ramp Meter shutdown test • With Metering 261 crashes • Without metering 476 crashes • Annual Savings from metering • Property damage only • $4.8 million • Injuries • $6.8 million • Fatalities • $6.6 million

  7. 43% Portland, OR 20% Los Angeles, CA 38% Seattle, WA 26% Minneapolis, MN 15% Long Island, NY Reduction in Crashes

  8. Benefits of Ramp Meters PREPARE TO STOP • Improved traffic flow from surface street to freeway • Faster travel times • Reduced merging accidents • Reduced fuel consumption • Reduced vehicle emissions

  9. Design Considerations • Some ramps dropped out of consideration during design phase • “slip” ramps – such as I-85 frontage road system • Ramps with very short storage • C/D ramps • No “geometrical” changes allowed • No widening • Some striping changes allowed if shoulders maintained • Acceleration distances • AASHTO Green Book compliance maintained

  10. History of Ramp Meters in Atlanta Begin Phase II –the Modern Years • Preparation for Olympics in 1996 • Congestion was back, relief needed and capacity was fixed • Pilot project – 5 ramps selected • Meters began operation December 1996 • Low impact ramps were selected for the pilot: • No widening/extending • Single lanes • Not a big residential area • Relatively low volumes

  11. Downtown Atlanta 1967 – Atlanta History Center

  12. Ramp Meter Pilot I-75 NB • Meters programmed to turn ON at 3:45 PM weekdays (TMC Planning) • Loop Detection with 3 second gap • Max rate set on the fly • Minimize delay on ramp (adjust rate) • Longer ramps = Adjust rate up • Shorter ramps = Adjust rate down • Meter ramps as needed on individual basis • Base rates on various time of day schedule

  13. History of Ramp Meters in Atlanta Phase III – the ‘Fast Forward’ years (2006-2012) • GDOT elected to go “all in” • Funding mechanism, Governors’ “Fast Forward” program • 18 year worth of congestion-relief projects in 6 years • Included 165 more ramp meters • Staged installation, one freeway at a time

  14. Meters on as of January 2009 GA 400 I-85 I-75 I-20 I-20 I-75 I-85

  15. Meters on as of January 2010 GA 400 GA 400 I-85 I-85 I-75 I-75 I-20 I-20 I-20 I-20 I-75 I-75 I-85 I-85

  16. Georgia Ramp Meter System Today GA 400 I-75 I-85 I-20 I-85 I-75

  17. Current Ramp Meter Locations • 185 Ramp Meters: • Original 5on I-75 NB, Midtown to Cumberland Mall (1996) • 27 Locations on I-20 • 51 Locations on I-285 • 8 Locations on I-575 • 40 Locations on I-75 North and South of Atlanta • 15 Locations on the 75/85 Connector • 19 Locations on I-85 • 2 Locations on the Buford Connector • 15 Locations on GA 400 • 8 Locations on US 78

  18. Operations- GDOT Mindset GDOT’s goal: partner with locals to provide the best possible travel time for the public. best = more consistent and reliable Ramp meter’s objective: Aid the mainline while limiting the impact from arterial networks supplying demand. How do we do that? • Providing consistent flow for merging vehicles Resulting in improved • Mobility • Safety

  19. Operations – Day to Day Queue Management • Making sure that arterials aren’t negatively impacted How do we do that? • Remote monitoring – during peaks • Navigator 2 • Centrally connected system • Threshold adjustments • Speed up metering • Shut down • Ramp • Mainline (Testing)

  20. Queue Management WITH … WITHOUT …

  21. Results 285 Westbound – PM peak – from Chamblee Dunwoody to I-75 (9 Miles) Travel Time reduced 6 Minutes

  22. Results 285 Eastbound – PM peak from Roswell Rd to I-85 (8 Miles) Travel Time reduced 5 Minutes

  23. Result Summary • Travel time reductions ranged from: • 50 seconds to 6 minutes • 8 – 35% • # of stop reductions ranged from: • 0.7 to 5.3 • Total delay reductions ranged from: • 30 seconds to 5 minutes • 11 to 82%

  24. Result Summary • Emissions data was also collected • Hydrocarbon (g) reductions ranged from: • 5 to 31% • Oxides of Nitrogen (g) reductions ranged from: • 5 to 38% • One corridor increased 6% • Carbon Monoxide (g) reductions ranged from: • 1 to 15% • Two corridors had increases (1% and 13%)

  25. I-285 Westbound PM Peak

  26. Thank you • Marc Plotkin • Traffic Engineer II • mplotkin@dot.ga.gov

More Related