I-485/85 innovative interchange design is number one in "Roads and Bridges" magazine Friday, October 5, 2012


CHARLOTTE – The October issue of “Roads and Bridges” magazine has named the I-85/I-485 turbine interchange in Charlotte the number one road project in North America for 2012. The awards are announced annually and are determined based on scope of work, regional impact and project challenges.


“Over the past three years, we have been able to move forward with critical transportation projects like this one using innovative financing and construction methods such as design-build-finance and the Mobility Fund,” said Gov. Bev Perdue. “It is great to this innovation recognized at the national level.”


The N.C. Department of Transportation awarded the design-build team of Lane Construction/STV-Ralph Whitehead Associates the $92.2 million contract in July 2010 to modify the existing I-85/I-485 interchange in northeast Mecklenburg County. Originally, NCDOT had proposed building a four-level stack interchange. The design-build team, however, presented the turbine design, which circles all left-turning traffic around a central bridge in a clockwise direction, because it offered several benefits:


  • Rather than building four levels, the turbine would require only two, which would reduce the potential to close the bridges in icy conditions;
  • Although the design contains 18 bridges, they are smaller with spans that are easier to build and maintain;
  • The turbine will provide better sight distance to motorists; and
  • It did not require the purchase of additional land.


This design saved an estimated $40 million. The interchange is scheduled for completion in June 2014, improving travel in the Metrolina region with a seamless transition between the two highways.


Gov. Perdue announced in November 2009 that NCDOT would coordinate construction work and use an innovative method called design-build-finance to complete I-485, widen I-85 and complete the interchange years ahead of schedule. Now, all three projects will be complete in 2014, one year sooner than the projects were originally scheduled for construction to begin at a savings to taxpayers of about $140 million.


More information on the turbine interchange and the other projects can be found here.


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