Bridge work is another major component of this project. Adding new lanes means widening 10 bridges along this corridor and fully replacing three others. Some of the bridges currently under construction include New River Road, New River Wash and Moores Gulch. 

Controlled rock blasting and earthwork are the biggest operations currently underway for the I-17 Improvement Project. This work began in 2022 and will continue throughout much of 2023. The rock blasting is necessary to make way for the additional general purpose lanes and 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 are a new feature for Arizona’s highway system and are designed to reduce congestion on I-17 during peak travel times.   

“The earthwork and excavation are impressive. It’s an operation where 1.7 million cubic yards of material will be removed from the mountainsides, then hauled to another area where it’s prepared and crushed,” said Annette Riley, ADOT’s project manager for the I-17 Improvement Project. “All the material that is blasted and excavated will go back into the project to construct the new lanes. We’re using everything that we remove.” 

Because I-17 is such a heavily traveled corridor, a significant portion of the construction work occurs during the weeknight overnight hours from 7 p.m. to 6 a.m. when lane closures and restrictions are allowed. However, the majority of the work still happens during the day as crews work in the median or on the sides of the highway. 

ADOT recently reduced 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. DPS said it is increasing its patrols and presence throughout the work zone to ensure continued safety for construction crews, drivers and passengers.  

“The message is simple. Drivers need to slow down and pay attention in the work zone,” said Riley. “Please obey the reduced speed limit and watch for construction workers, vehicles and equipment. We want everyone to get to their destinations safely, and we also want all of our highway workers to get safely home.” 

More about the I-17 Improvement Project:

Once complete in 2025, the I-17 Improvement Project will help alleviate congestion and improve safety and traffic flow north of the metro Phoenix region. The 23 miles of improvements include 15 miles of roadway widening from Anthem Way to Black Canyon City. One travel lane will be added in each direction along this stretch. In addition, an eight-mile flex lane system will be constructed from Black Canyon City to Sunset Point. Flex lanes are a new feature for Arizona’s highway system and are proven technology to help reduce congestion on I-17 during peak travel times and allow for traffic movement during emergency situations.

The I-17 flex lanes will operate as a separate, two-lane roadway carrying one direction of traffic at a time depending on the greatest need along the steep, winding eight miles between Black Canyon City and Sunset Point. For example, the flex lanes will be able to carry heavy northbound traffic on a Friday or heavy southbound traffic on a Sunday. Similarly, ADOT will be able to open the flex lanes to accommodate traffic any time if a crash or other incident causes long delays.

The two flex lanes will be next to, but physically separated from southbound I-17 using concrete barriers. Access to the flex lane entrances will be controlled by a series of swing gates. Dynamic overhead guide signs will alert drivers to the open direction of the flex lanes. The flex lanes will be operational seven days a week.

For more information about the I-17 Improvement Project, visit improvingi17.com, call 877.476.1717 or email info@improvingi17.com.