The $288 million Johnson County Gateway project is the first major design-build project awarded by the Kansas Department of Transportation (KDOT). Clarkson Construction Company is the joint venture sponsor for Gateway Interchange Constructors (GIC), a Joint Venture between Clarkson Construction Company (65%), and Kiewit Infrastructure Group (35%) for this “set value” project. “Set value” means that the design-build proposer is required to define the project scope that would be provided to KDOT for $285 million with the additional $3 million being an allowed incentive if the design-build proposer committed to completing the project by December 31, 2016 – seven months ahead of the required completion date.
The project includes the reconstruction and capacity improvements on I-435 from US-69 westerly to K-10 and northerly to 95th Street, K-10 from I-435 westerly to Woodland Road and I-35 from I-435 northerly to 95th Street. It also includes reconstruction and reconfiguration of the interchanges of I-435 & I-35, I-435 & Lackman Road, I-435 and K-10, K-10 and Renner Road, K-10 and Ridgeview Road, and I-35 & 95th Street. The project also includes Renner Road, Lackman Road, Pflumm Road at I-435, Pflumm Road at I-35 and College Boulevard from Renner Road to Ridgeview Road. Three different municipalities were involved and invested in this project with KDOT, and served as stakeholders throughout the project duration. Two collector-distributor roads will be built on either side of I-435 to alleviate traffic weaving to exit at city streets, and two diverging diamond interchanges were constructed for two different cities as part of this project.
A total of twenty-seven bridges are included in GIC’s project, including two large structural steel flyovers in the I-435/I-35 interchange, a large precast concrete beam flyover in the I-435/K-10 interchange, four precast concrete beam bridges over the BNSF Railway, four precast concrete beam bridges on I-435 over Pflumm Road, two structural steel bridges and two precast concrete bridges over Lackman Road, a precast concrete bridge on Ridgeview over K-10, a new precast concrete bridge and two bridge rehabilitations on K-10 over Renner Road and two precast concrete bridges on I-435 over K-10. A total of 146,000 square feet of bridge decks are included in the project. Additionally, 200,000 square feet of mechanically stabilized walls, and 30,000 square feet noise walls are to be constructed.
The project includes 2,000,000 cubic yards of earth and rock excavation, 650,000 square yards of new concrete pavement, 125,000 square yards of asphalt streets, 770,000 square yards of lime and/or fly ash treated subgrade and 690,000 square yards of cement-treated base. Drainage improvements include over 5,000 linear feet of precast concrete box culverts, 72,000 lineal feet of concrete pipe and over 650 inlet structures. Specialty construction items included: traffic signals, highway lighting, highway signing, numerous utility relocations, traffic control, pavement marking, erosion control, seeding & mulching and aesthetic treatments. All work is to be constructed while maintaining over 240,000 vehicles per day through the project corridor.