Drivers who travel Interstate 17 between Anthem Way and Sunset Point will undoubtedly notice a very different scene, as construction along this 23 miles of scenic highway is well underway.
Before the road is widened and the flex lanes are added, there is significant bridge work that must take place. The New River Road traffic interchange at milepost 232 has been under construction, as the bridges on both the northbound and southbound sides need to be widened from two lanes in each direction to three lanes. Massive girders were recently installed on both bridges in order to support the bridge decks, or the actual roadway, that vehicles will travel over once the project is complete.
The girders were set during the overnight hours, which is when most of the work is completed for the Arizona Department of Transportation’s I-17 Improvement Project(link is external). Crews from the Kiewit-Fann Joint Venture developer team set nine girders on each bridge during a two-night operation. There are three sizes of girders, or beams, with the largest weighing about 45,000 pounds (22.5 tons) and the smallest weighing about 30,000 pounds (15 tons).
Setting the girders is a critical operation for the construction crews and one that requires several hours of careful work. Getting the girders hoisted up and then set into place requires significant coordination, safety precautions and quality control. Girder placement signifies the start of completing the bridges at the New River Road traffic interchange, which is a major milestone.
The New River Road traffic interchange bridges are the first two of 10 bridges that will be widened as part of the I-17 Improvement Project. These two bridges are expected to be fully completed by late summer. Three additional bridges are being fully constructed or replaced as part of this project.
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 gates. Overhead message signs will alert drivers to the open direction of the flex lanes. The flex lanes will be operational seven days a week.