I-17 Flex Lanes

Black Canyon, Arizona

To reduce congestion and travel delays along a critical section of I-17, the Arizona Department of Transportation selected the Kiewit-Fann Joint Venture (KFJV) to provide design and construction services to make improvements to over a 23-mile stretch of I-17 from Anthem Way to Sunset Point. This required adding a single lane in each direction over the 15 miles between Anthem Way and Black Canyon City and two flex lanes over the remaining eight miles, allowing traffic to switch directions as needed. The flex lanes will be used to relieve traffic congestion in the northbound lanes from Friday to Saturday night and southbound lanes from Sunday morning through Monday.

The project introduced several key safety and infrastructure upgrades, including the replacement of guardrails with concrete barriers, enhanced pavement markings, delineators, rumble strips, curve warning signs and chevrons. Dynamic message signs were installed near mileposts 248 and 251, along with vehicle arresting barriers and movable gates.

The project also involved significant excavation and paving work to improve sight distance and safety, with 2 million cubic yards of rock excavation, 360,000 cubic yards of aggregate base course and 450,000 tons of asphalt.

In the southern portion of the project, the recommended interim build alternative included adding lanes in both directions, with the northbound roadway widened towards the median and the southbound I-17 expanded from just north of Anthem to just south of New River. These enhancements are designed to improve traffic flow and safety along this vital corridor, ensuring it meets the growing demands of the region.