This is a diverging diamond, a innovative traffic relief solution that takes advantage of existing infrastructure and is quicker and cheaper to build than traditional lane-widening. (You should be able to click on the image for a larger view.)
There are only 5 of these in the country right now, but two more are under consideration for Gwinnett County, one at Pleasant Hill and I-85, the other at Jimmy Carter and I-85.
UPDATE! Apparently there are also DDIs under construction at Ashford-Dunwoody and I-285 and someplace called “Cobb County.” More “how they work” details on that project are available at John Heneghan’s Dunwoody blog and “where the money comes from” details at State Rep. Mike Jacobs’ blog.
Brian Allen, director of the Gwinnett County Department of Transportation, said the DDI projects are much-needed improvements that should increase capacity and help ease traffic congestion in two of the county’s busiest travel areas.
“We are pleased with the successful collaboration of state and local transportation with the CIDs to conduct this innovative work that is entirely funded by SPLOST and CID money. ” Allen said. “It’s much less expensive than traditional interchange reconstruction because we’re using the existing bridges in a new way.”
The Gwinnett Place CID and the Gwinnett Village CID, in collaboration with County and State transportation departments, can fund the project through existing SPLOST revenues and CID taxes.
“The DDI is truly a revolutionary system that allows drivers to cross over to the ‘opposite’ side of the road as they access the interstate, and because the new interchange uses the existing infrastructure, these DDI’s construction time and dollars needed are dramatically less than building a new interstate crossing,” said Mark Williams, Chairman of the Gwinnett Place CID Board of Directors.
“Relieving congestion has been one of our top priorities since the CID was formed in 2006,” said Chuck Warbington, executive director for the Gwinnett Village CID. “The Jimmy Carter Boulevard and I-85 interchange is a major point of entry to our district and our goal with the Diverging Diamond redesign is to enhance accessibility to local businesses and to reduce overall congestion in the corridor.”
Open houses for public input and commentary will be held Thursday, Feb. 24 – 4 p.m. to 7 p.m Atlanta Marriott Gwinnett Place (1775 Pleasant Hill Road, Duluth) for the Pleasant Hill Road DDI, and Tuesday, March 1 – 4 p.m. to 7 p.m. at the Gwinnett CID offices (5855 Jimmy Carter Boulevard Suite 122, Norcross) for the Jimmy Carter Boulevard DDI.
I don’t know how these things work, but they seem to be pretty cutting-edge. Kudos to the respective CIDs for pushing forward -the drivers of Gwinnett thank you.
Here’s a video of one in action. I still don’t get it.