Gridlock Guy: GDOT experts explain the changes on I-285 and GA-400

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Drivers can expect new barriers, new signs and new striping with the massive overhaul of the 285-400 interchange.

When Eric Von Haessler and the Doctrinnaires go away, WSB Triple Team Traffic gets to play. We hosted a special roundtable hour at 9 a.m. last Thursday on News 95.5/AM750 WSB with Georgia Department of Transportation officials, to take a deep dive on the status of the Transform I-285/GA-400 project. We also wanted to put the stories into straight lines about the future tolled Express Lanes along GA-400 and I-285. So Smilin' Mark McKayAshley FrascaMark Arum, and I became a firing squad of questioners.

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The WSB Traffic Team and GDOT host the Triple Team Traffic special on WSB Radio on May 23rd, 2019. (L-R): Tim Matthews, Doug Turnbull, Natalie Dale, Marla Clowers, and Smilin’ Mark McKay. Credit: Ashley Frasca

The WSB Traffic Team and GDOT host the Triple Team Traffic special on WSB Radio on May 23rd, 2019. (L-R): Tim Matthews, Doug Turnbull, Natalie Dale, Marla Clowers, and Smilin’ Mark McKay. Credit: Ashley Frasca
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The WSB Traffic Team and GDOT host the Triple Team Traffic special on WSB Radio on May 23rd, 2019. (L-R): Tim Matthews, Doug Turnbull, Natalie Dale, Marla Clowers, and Smilin’ Mark McKay. Credit: Ashley Frasca

» RELATED: Gridlock Guy: Residential cost of GA-400 expansion illustration of bigger conundrum

GDOT has worked with the state legislature and former Governor Nathan Deal the past few years to initiate and start funding a host of Georgia roads projects - most of which are in Atlanta - to address the boom in population and the increased freight traffic. Georgia’s population has grown almost 16% since 2010. The I-285/GA-400 interchange redesign actually preceded the more recent initiatives.

The future Express Lanes and Transform I-285/GA-400 are two separate endeavors. The construction happening now in Sandy Springs/Dunwoody is strictly to redesign the I-285/GA-400 interchange and improve the traffic at the exits closest to it. When traffic in that area is jammed, those delays radiate elsewhere.

“We refer to I-285 as a wheel and the wheel has to turn for I-285 to work,” GDOT spokesperson Natalie Dale explained during our show. “And when you have one of the spokes of that wheel broken, that wheel doesn’t turn.” The boom in population and business in that busy corridor simply is not sustainable, without major changes on the roads.

“We are rebuilding a lot of the ramps that connect I-285 and 400,” Transform I-285/GA-400 project manager Marla Clowers said on WSB. “We’re also building collector-distributor lanes and those lanes take traffic that is entering and exiting the interstate off of the main line.” In other words, the high percentage of the 250,000 vehicles that use that interchange daily that exit between Roswell Road and Ashford Dunwoody Road on I-285 and between the Glenridge Connector and Abernathy Road on GA-400 will see changes. Those motorists will have to commit to their exits early and enter the freeways later, which channels traffic out of the regular lanes. Barriers will protect these CD lanes, which should prevent the constant lane-weaving. Lane changes, exiting, and entering cause more delays and increase crashes.

The interchange improvements and the eventual added capacity of Express Lanes should also greatly improve area surface street traffic and better allow for future population growth.

Some surface streets adjoined to I-285 and GA-400 are feeling the growing pains of the project. The I-285/westbound (Outer Loop) ramp to Peachtree Dunwoody Road (Exit 28) has been re-striped to one lane, which has jammed the freeway even worse. But Peachtree Dunwoody Road/northbound itself is now just one lane wide under the I-285 bridge. Clowers said crews have done this here and similarly on Mount Vernon Road, Abernathy Road, and the Glenridge Connector to allow for bridge reconstructions, ramp reconfigurations, and to better connect these roads to the project. Among other things, workers have to change those lanes to move obstructing utilities (such as underground water lines) and give themselves room to build.

Clowers also unearthed another interesting project tidbit about the 14,000 tons of rock crews blasted to allow for the new lanes. “We have hopes that it will be able to be used on the project, so we don’t have to bring it all in. We’ll make our own.” Testing facilities analyze the rock to ensure its appropriateness for use.

The Transform I-285/GA-400 project is set to conclude at the end of 2020, but additions to the plan and weather could completion to 2021.

Next week, we will explain the timeline of the aforementioned Express Lanes that will be different than others on Metro Atlanta’s freeway system and won’t begin operation for several years.

Listen to the full podcast of the show in the On-Demand tab on wsbradio.com. The podcast also includes testimonials from Veronica Harrell and Alex Williams on the worst midday traffic shift they ever worked together.

» RELATED: New lanes coming for I-285, putting some neighborhoods on edge

Doug Turnbull, the PM drive Skycopter anchor for Triple Team Traffic on News 95-5 FM and AM-750 WSB, is the Gridlock Guy. He also writes a traffic blog and hosts a podcast with Smilin’ Mark McKay on wsbradio.com. Contact him at Doug.Turnbull@coxinc.com.