When it’s completed in late 2019, construction crews for the South Mountain Freeway will have hauled and compacted about 10 million cubic yards of earth.
The dirt is the equivalent of more than 800,000 truckloads, which would be enough to fill University of Phoenix Stadium 13 times. It’s also an important part of building the roadway surface along with building bridges and wall foundations that will be used to connect embankments and connecting ramps.
“One of the most important parts of freeway construction is building the foundation, which requires large amounts of dirt material,” said Rob Samour, ADOT’s senior deputy state engineer for major projects said in a press release. “Compacting this amount of dirt takes time, but it’s essential to ensure we’ll have a stable roadway for decades to come.”
According to the press release, some of the earthwork requires digging dirt out of areas such as the cross street at Desert Foothills Parkway to build an underpass or the existing I-10 embankment to create access roads that will parallel the freeway.
ADOT said that about a 10th of the dirt will be imported including loads that will be hauled and delivered overnight to minimize traffic congestion. ADOT added that at a part of the project located near the Salt River in Laveen, 1.1 million cubic yards of dirt will be used to fill in a former sand and gravel pit.
When finished the 22-mile freeway will be the largest highway project in Arizona as it will connect the Loop 202 freeway in the East Valley to the Interstate 10 in the West Valley, allowing motorists to cross the Pheonix metro area while avoiding downtown.
The long-planned freeway was originally approved by Maricopa County voters in 1985 and again in 2004.