A new, completely redesigned interchange at one of Tulsa’s busiest intersections is in the planning stages, and the public is invited to learn more.
The Oklahoma Department of Transportation is proposing a new Diverging Diamond Interchange — or DDI — at the intersection of Memorial Drive/U.S. 64 and the Creek Turnpike/U.S. 169 in south Tulsa.
Following public input during a virtual open house this month, the design phase of the project would be ongoing through early 2022, with construction beginning in late 2022 and competed in late 2024.
Construction bids for the project are anticipated to be accepted in 2022. An estimated cost has not yet been determined, ODOT spokeswoman Kenna Mitchell said Thursday.
“This is a heavily congested interchange, and travelers experience significant delays at the current access points,” ODOT said in a news release.
The DDI design “reduces several left turn conflict points and congestion by shifting traffic to the opposite side of the roadway at the ramp areas through a series of traffic signals,” the agency said.
Vehicles traveling through the DDI cross over to the opposite side of the roadway so that left turns no longer cross the path of oncoming traffic.
“While crossing to the opposite side of the road may sound confusing, vehicles are guided through the interchange via use of channelized islands, and signing and striping enhancements on the roadway make the routes very clear for drivers to get accustomed to the new design,” ODOT said.
“Removing left turns from the traffic signals greatly increases the number of vehicles that can pass through the signal during a cycle.”
A conventional diamond interchange has 18 conflict points, or locations where collisions can occur. A DDI reduces this to eight, ODOT said.
The project would be built using existing public rights-of-way, meaning utility poles and private property would not be affected, Mitchell said.
Access to nearby businesses will be maintained during the project, ODOT said.
During construction, at least one lane of traffic will remain open on all ramps, and two lanes of traffic are planned to remain open in each direction on Memorial Drive, ODOT said.
Traffic on the Creek Turnpike is not expected to be significantly affected.
More than 200 DDI interchanges have been completed across the country since the first one opened in Springfield, Missouri, in June 2009.
“The original DDI constructed in Springfield … reduced collisions by 60% over five months,” ODOT said.
“A survey done by the Missouri DOT shows that 97% of drivers feel safer using the new DDI. Daily traffic backups that were up to a mile long were completely eliminated after the DDI was completed.”
The first DDI in Oklahoma was recently completed in Elk City at Interstate 40 and Oklahoma 6. The Tulsa project would be the second such interchange in the state, Mitchell said.
Virtual open house: The public can visit www.odot.org/US64-US169Tulsa through July 28 to view the proposal, including an interactive map and video showing how a DDI functions, and also provide comments which can assist in further plan development.
Due to COVID-19 precautions, the presentation is a web-based public viewing format with no in-person meetings scheduled, ODOT said.
Those without internet access can contact the ODOT Environmental Programs Division at 200 N.E. 21st St., Ste. 3-D2a, Oklahoma City, OK 73105 or call 405-521-3050.