Someday, I-10 between Tangerine Road and its intersection with I-8 near Casa Grande is going to be 10 lanes, five westbound and five eastbound, with continuous one-way frontage roads in both directions, and an open median for future expansion that could accommodate truck-only lanes or a rail line.
Nine new interchanges – including one at Moore Road in Marana, and another at Tortolita Boulevard just south of the Pinal County line — and several interchange relocations are part of preliminary designs for the 44-mile stretch of highway.
Considerable changes would be undertaken at the I-10 intersection with I-8 to address inadequate spacing with other interchanges, and because the current interchange is inconsistent with design standards. I-10 would be realigned through the community of Picacho, eliminating some curvature, allowing a consistent 75-mph speed limit, lowering elevated roadway and improving visual impacts. The Sunland Gin Road and Pinal Air Park interchanges are among those that might be moved, and improvements to the Red Rock interchange are anticipated.
When might the 10-lane project begin? "It's difficult for us to answer that question," Michael Kies, project consultant with the firm AECOM, told an audience at a public hearing Thursday, Sept. 30 at Estes Elementary School in Marana. "This is the first step of a long process for the I-10 corridor."
"There could be a long gap" after widening to six lanes is complete, and before 10 lanes are undertaken, Kies said. He suggested 10 to 20 years. The planning of improvements takes "years and years."
This work is needed, according to ADOT information, because the road needs more capacity for future growth, including more lanes, more ramps, and more acceleration and deceleration lanes. A parallel frontage road route along I-10 in each direction is needed for emergency traffic and local access. When there are accidents, "traffic can be stuck for several hours at a time," Kies said.
An improved I-10 can "support the objectives of the CANAMEX trade corridor, which includes this important segment of I-10," literature indicates. The CANAMEX corridor presumes greater traffic between Mexico and Canada through the U.S. I-10 is "not only an important east-west freight route," but decision-makers "expect freight movements to increase north and south."
An initial design concept has been identified. A draft environmental assessment has been conducted. "All information is still in draft form," awaiting public comments and concerns, Kies said. "It's not finalized until we've reviewed comments, and considered how to incorporate those into the study."
The draft environmental assessment includes recommendations for four new noise walls, among them a 2,640-foot-long, 20-foot-high wall near Estes Elementary that would be an addition to the recently installed wall at Marana Middle School.
Right now, federal stimulus funds and other dollars are being used to widen two sections of I-10 from four to six lanes. Overall, six "interim" widening projects on the I-10 section are in the Arizona Department of Transportation pipeline. In two projects, 21 miles of the roadway have been widened from four to six lanes. Widening of six miles from the east end of Picacho to Picacho Peak Road is under construction, as is widening of 11 miles from I-8 into Eloy. Two other widenings are in design, and should be completed "within the next several years," Kies said.
"Could you beautify the center medians?" one guest asked.
"To do that would be incredibly expensive, it really would," ADOT Tucson district engineer Todd Emery responded. "We will try to do enhancement projects as we can at interchanges." The nearly-complete Twin Peaks interchange is "a good example" of what can be done. But the placement of decomposed granite, plants and irrigation lines represents "an incredible, incredible cost to maintain, and keep it looking good."
There are no plans for new rest areas along the stretch.
Comment forms were distributed at the public hearing, and comments are welcome through Oct. 14. Communication from the public has been "very, very helpful to us," ADOT spokeswoman Linda Ritter said, and has helped shape decisions.
A draft environmental assessment on improvements to I-10 between Tangerine Road and I-8 is available at http://www.i10tucsondistrict.com/i8totang2">www.i10tucsondistrict.com/i8totang2. A copy of the document is available for public review at the Wheeler Taft Abbett Sr., Library, 7800 N. Schisler, Marana.