MoDOT, District 8, Springfield -- The first-in-the-USA "Diverging Diamond Interchange," at Kansas Expressway (Route 13) and I-44 in Springfield, will be dedicated in a brief ceremony at 3 p.m. Tuesday, July 7, the Missouri Department of Transportation said.

A ribbon will be cut in a cleared area on the northeast corner of the interchange -- AWAY from traffic. Access is off of Norton Road east of Kansas Expressway.

The $2.9-million project is completed a few days ahead of the scheduled July 10 deadline. The new interchange was opened to traffic on Sunday, June 21.

The prime contractor is Hartman & Company Construction of Springfield.

MoDOT's project manager on the innovative project is Don Saiko. The Springfield area District Engineer is Kirk Juranas.

Springfieldian Jim Anderson, who recently completed a term on the Missouri Highways and Transportation Commission, will preside over the event. Anderson is president of the Springfield Area Chamber of Commerce. Among those scheduled to make brief remarks are Springfield Mayor Jim O'Neal and Greene County Presiding Commissioner David Coonrod.

The City of Springfield was a financial partner with MoDOT in the project. The city used funds from a voter-approved 1/8-cent transportation sales tax. MoDOT and Springfield each contributed $1.45 million for the project.

First-in-USA 'Diverging Diamond Interchange'

With the Diverging Diamond Interchange, or DDI, design, the opposing lanes of Kansas Expressway criss-cross at traffic signals at the ends of the bridge over I-44. Crossing the bridge, oncoming traffic is on the right, separated by concrete barriers.

This gives left-turning vehicles on Kansas Expressway a "free left" onto the I-44 on-ramps. At the same time, two lanes of traffic continuing north or south on Kansas Expressway are able to travel more steadily through the interchange.

Signs, pavement markings and concrete islands guide drivers through the interchange.

The Diverging Diamond Interchange in Springfield is the first of its type built in the United States. MoDOT is planning a similar Diverging Diamond project in cooperation with Springfield on National Avenue at the James River Freeway (Route 60). Projects are being planned in Kansas City and St. Louis.

Transportation departments in other states are planning or already building Diverging Diamond Interchange projects.

The design is in use in Europe.

Reasons for using a Diverging Diamond design:

MoDOT engineers believe the Diverging Diamond Interchange is a good fit for the Kansas Expressway/I-44 interchange. It will help relieve congestion in a tight area and yet was a quicker, cheaper reconstruction than more conventional interchange projects:

* The existing bridge, still in good condition, was rehabilitated -- a much simpler project than replacement.

* Construction was completed in about six months instead of up to two years as would be required if a new bridge had to be built. That meant a shorter time period for traffic disruptions.

* The $2.9-million project is about one-third the cost of a more standard rebuilt interchange.

* Left-turn crashes (from Route 13 onto I-44) should be eliminated and rear-end crashes reduced. That means much-improved safety.

Project Details

The project involved:

* Removing the existing driving surface on the bridge, repairing the deck and putting down a new driving surface.

* Building a pedestrian walkway down the center of the opposing lanes, divided by concrete barriers.

* Installing new traffic signals, new striping and other pavement markings, new overhead signs, new islands, new highway lighting and LED lighting for the pedestrian walkway.

* Building a new ramp for westbound I-44 to Norton Road-only.