Work on Diverging Diamond Interchange Starts Oct. 29
Springfield, Greene County -- Work to convert the Kansas Expressway/James River Freeway interchange to a Diverging Diamond Interchange begins the week of Oct. 29, with completion scheduled by the fall of 2013, the Missouri Department of Transportation said.
The project includes rebuilding a section of pavement on Kansas Expressway (Route 13) between Chesterfield Boulevard and James River Freeway (Route 60) and repairing the deck of the Kansas Expressway bridge over James River Freeway.
Kansas Expressway will be converted to a Diverging Diamond Interchange design, with traffic crossing to the left-hand side of the road at new traffic signals on either side of James River Freeway.
Congestion on Kansas Expressway, which has many cars making left-hand turns from Kansas Expressway onto the freeway competing with considerable through traffic, makes the interchange a good candidate for the Diverging Diamond Interchange design.
While drivers can expect nighttime lane closings at times through the winter on both Kansas Expressway and James River Freeway, major disruptions are not scheduled to occur until March. When lane closings are needed, they will take place between 8 p.m. and 6 a.m.
Traffic impacts during construction
* October 2012 into March 2013: Drivers can expect nighttime lane closings on Kansas Expressway and James River Freeway as crews grade dirt to widen ramps and install storm drains.
* Mid-March 2013: Kansas Expressway will be reduced to three lanes -- two southbound lanes and one northbound lane -- with traffic shifted to the east side of the bridge over James River Freeway. The lane reduction is needed for pavement reconstruction and bridge repairs.
* Early May 2013: Kansas Expressway traffic will be shifted to the west side of the bridge, with three lanes of traffic remaining open -- two southbound and one northbound. Crews will continue work on pavement and bridge repairs.
* Early August 2013: Kansas Expressway will be closed over a weekend to complete the conversion of Kansas Expressway to the Diverging Diamond Interchange design.
Features of Diverging Diamond Interchange
The goal of converting Kansas Expressway to a 'Diverging Diamond Interchange' is to make driving safer and easier for drivers on Kansas Expressway, improving flow for both left-turning and through traffic and eliminating right-angle crashes.
By the end of 2012, Springfield will have three Diverging Diamond Interchanges in place -- Kansas Expressway and I-44 (2009), National Avenue and James River Freeway (2010) and Chestnut Expressway and Route 65 (November 2012).
After the conversion in August:
* Traffic on Kansas Expressway will be shifted to the left-hand side of the road at new traffic signals at the ramps on either side of James River Freeway.
* Kansas Expressway traffic turning left onto James River Freeway will get a "free left," meaning drivers will already be on the left-hand side of the road and will NOT have to turn left in front of oncoming traffic.
* Through traffic on Kansas Expressway will return to right-hand side of road at a new traffic signal after traveling over James River Freeway.
* New traffic signals, signs, pavement markings and concrete islands will guide drivers along Kansas Expressway, whether turning onto James River Freeway or going straight through the interchange.
* Two concrete walls will separate northbound and southbound Kansas Expressway traffic, with a pedestrian walkway built in between the walls.
Background on the Diverging Diamond Interchange design and animations that show how to drive it can be found at modot.org/southwest .
The prime contractor is Hartman Construction, Springfield.
Construction cost: $2.6 million.
The project is a partnership between MoDOT and the city of Springfield.
Speeding in the work zone when workers are present will add $250 to the total fine for drivers who are ticketed. Signs will be posted with that warning.
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