Crews have completed blasting to remove sections of mountains as part of the Interstate 17 widening project north of the Phoenix metro area, state transportation officials said.

The work was was necessary to make way for additional lanes from Anthem Way to Sunset Point. That includes 15 miles of widening and 8 miles of flex lanes along the entire 23-mile I-17 Improvement Project corridor. 

Controlled rock blasting began in December 2022 and required full closures of I-17 in both directions for safety reasons.

Blasting took place at 10 p.m. during the weeknights and involved a tight schedule, according to the Arizona Department of Transportation. Crews had one hour to close the highway, carry out the blasting operation, clear the debris and reopen the highway. 

Sixty-two blastings at seven different locations along the project corridor occurred over a year, ADOT officials said.

“That’s far less than the initial estimate of 120 blasts,” officials stated in a release.

“In many circumstances, crews were instead able to ‘rip’ or excavate rock in certain areas using heavy equipment. Ripping is the preferred method of rock removal because it lessens the impacts on traffic. Areas where the rock material was too hard to be ripped needed to be blasted instead.”

About 177,000 cubic yards of rock and material was removed during the blasting process, then hauled to another area of the project to be incorporated into the new roadway. A large portion of the blasted material is crushed and then used as aggregate base, embankment and rock mulch along the 23 miles of new lanes, according to ADOT.

The entire 23-mile stretch between Anthem Way and Sunset Point remains under construction throughout 2024 and into 2025, as the new lanes are constructed and paved and a dozen bridges are either widened or replaced.

The 15 miles of new lanes between Anthem Way and Black Canyon City are expected to open by the end of 2024, and the eight miles of flex lanes between Black Canyon City and Sunset Point are expected to open in 2025.