The Missouri "Triangle" is 40 years old and carries more than 250,000 vehicles per day through Kansas Citys crowded southeastern corridor. Three major arterial highways converge there, Interstate 435, I-470 and Highway 71, carving in the landscape a three-sided interchange with 64 unique movements. The once-tangled bottleneck serves as a signification focal point for the citys downtown businesses, suburban commuters and heavy-freight carriers.
"Besides those three major highways all coming together at the same point, you have seven other local interchanges all within a couple of miles," says Steve Hamadi, MoDOT project manager. The 540-acre project covers 70 lane-miles of new pavement, including replacing 26 bridges and building 17 new structures with 1-million sq ft of total bridge deck. The brides will sit atop 293 new columns rising between 20 ft and 125 ft tall.
Kansas City-based engineering firm HNTB designed the project without requiring roadbuilders to close lanes during peak travel times. "We are maintaining the same number of lanes that existed when we started construction," says Jim Kinder, HNTB project manager. Whats more, the Triangle will be linked up to the area's first intelligent transportation system called "Kansas City Scout." Using cameras, embedded sensors and electronic signs, the new ITS initiative covers 75 miles of highway spread across the Kansas-Missouri state line and will be partially operational in January 2004.
When complete, MoDOT expects the Triangle rebuild to save at least 360 accidents each year and increase the interchanges existing daily capacity to 440,000 vehicles. "Just the accident reduction alone would save us $23 million per year," Hamadi adds. Completion is scheduled for 2008 but Hamadi says state-funding problems may delay the project by two more years. "We expect to know early next year," he says.
The Dec. 3 opening of the new westbound I-470 ramp, part of the projects largest contract at $66 million, marks a second major milestone after local contractor Clarkson Construction Co. wrapped a $49 million southbound I-435 ramp rebuild 10 months ahead of schedule in October 2002.
The contractor also holds the current westbound I-470 contract and is moving fast toward final completion in March. "We are about four months ahead," says Rich Markey, Clarkson project manager.
The general contractor will receive an $8,000-per-day bonus for early completion with a 3% max-contract cap. This work makes room for another $50 million contract to replace eastbound I-470 in the opposite direction. The contract was awarded this past summer to APAC-Kansas, a local division of APAC Inc. of Atlanta and parent company Ashland Inc. of Covington, Ky. APAC's work is slated to finish in early 2006, with smaller projects to follow.
(Photos courtesy of HNTB/Dan Frueh)