Kansas City’s ‘Triangle’ continues to take shape

News HNTB Corp. February 03, 2006
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The Missouri Department of Transportation (MoDOT) continues to move forward one of the metropolitan area’s most complex and important interchanges. HNTB Corp. is submitting plans for the final phase of the Triangle interchange, which is now expected to be complete six to nine months ahead of the schedule established in 1999. Construction of the final phase will begin in July 2006, and the entire project is expected to be complete in the summer of 2008. MoDOT is pleased to be delivering the project as promised.

“We told the public at the start that the Triangle would be complete in 2008. We not only are keeping our commitment, we are ahead of schedule,” said Linda Clark, MoDOT’s assistant district engineer for project planning and development in Kansas City. “We’ve heard a lot of praise from the public as well. Travelers are pleased to see continual progress on the Triangle.”

Nonstop progress is the hallmark of what is considered an engineering marvel because of what was a tangled web of lanes, interchanges and bridges that are being reconfigured. The I-435/I-470/U.S. 71 interchange contains 50 lane-miles of pavement and more than one million square feet of new bridges and provides connections to five arterial streets.

“The greatest success of this project is that we have managed to maintain all traffic throughout construction, and the contractors have met or beat all of the project milestones,” said Jim Kinder, HNTB’s project manager for the Triangle. HNTB has provided design, public involvement and technology services to the Triangle project. “Traffic has actually improved during construction.”

One recent measure of traffic improvement is on eastbound I-470, which opened into two through lanes in September 2005. According to information provided by the KC Scout Intelligent Transportation System, average speeds during rush hour before the opening were about 23 mph. After the opening, rush hour speeds increased to 58 mph. The third through lane for eastbound I-470 opens in August 2006.

By the end of this year, all of I-470, I-435 and the connecting ramps will be completed. U.S. 71 traffic south of Red Bridge Road will be shifted to service roads, providing for construction of the final improvements to the interchange, which involves reconstructing U.S. 71 and adding an additional through lane for U.S. 71 throughout the interchange.

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