I-17 Improvement Project continues to progress after one year of major construction

PHOENIX – What a difference a year makes. If you’ve recently driven along Interstate 17 north of the Phoenix metro area, you’ve seen the flurry of construction activity, along with the distinct progress, as the I-17 Improvement Project moves toward a safer and more efficient corridor for all travelers. 

Today marks one year since major construction work began to add new general purpose lanes and flex lanes along the 23 miles from Anthem Way to Sunset Point. In addition to the new lanes, 10 bridges will be widened and two others will be replaced. Once complete in 2025, this major design-build project will help alleviate congestion and improve safety and traffic flow along a Key Commerce Corridor that is crucial to the state’s travel, tourism and economic development opportunities. 

The last 12 months have been largely dedicated to controlled rock blasting and earthwork, and this work will continue into 2024. The rock blasting is necessary to make way for the 15 miles of widening from Anthem Way to Black Canyon City, along with the eight miles of flex lanes, which will be constructed next to the existing southbound lanes from Black Canyon City to Sunset Point. The flex lanes, or reversible lanes, are a new feature for Arizona’s highway system and are designed to reduce congestion on I-17 during peak travel times. See this link for more information and an animated video.

Throughout the earthwork and excavation operations, a total of 1.7 million cubic yards of material is being removed from the mountainsides, then hauled to another area of the project to be reincorporated into the new roadway. A large portion of the blasted material is crushed to be used as aggregate base for the new roadway, and all the excavated material will go back into the project. The construction team is using everything that is removed.

Paving work in the southern section between Anthem Way and Table Mesa Road is one area where the crushed material is already being used as aggregate base. The paving began this summer and will continue into 2024. The paving process takes more than a year to complete because it requires four different layers, along with the appropriate weather conditions. Crews start with the subgrade, followed by aggregate base, then asphalt pavement, and finally, the top layer of asphalt (the “friction course”), which is the layer that motorists drive on. 

This major construction happens all while keeping I-17 open during the weekdays, weekends and holidays. Lane closures and restrictions only occur during weeknight overnight hours to minimize impacts to the traveling public who rely on this corridor. However, the majority of the work still happens during the day as crews work in the median or on the sides of the highway. 

As a reminder to drivers, ADOT lowered the speed limit to 65 mph along the entire 23-mile construction zone between Anthem Way and Sunset Point to enhance safety and reduce crashes due to excessive speed. The Arizona Department of Public Safety is partnering with ADOT to enforce the reduced speed limit. Both agencies strongly urge drivers to slow down, pay attention in the work zone, and watch for construction workers, vehicles and equipment. 

For more information about the I-17 Improvement Project, visit improvingi17.com.