Bypass could ease I-10 congestion in Tucson
by Garry Duffy on Mar. 02, 2007, under LocalBut it would cut through pristine San Pedro Valley
Park Link Drive, connecting Interstate 10 and state Route 79 north of Oracle Junction, could become part of a bypass around Tucson, state transportation officials say.
Heavy trucks and other traffic passing nonstop through Tucson and Phoenix could be routed off Interstate 10 to a bypass east and north of the Santa Catalina Mountains, under a concept the state is exploring.
The Arizona Department of Transportation will award a contract in April for a consultant to explore the idea of a four-lane highway.
It could run from I-10 near the Willcox and Benson area east of Tucson to I-10 west of Phoenix in Buckeye, running about 200 miles.
A bypass could relieve urban freeway congestion and minimize, if not eliminate, the need for future major widenings of I-10 in Phoenix and Tucson, supporters say.
One state Transportation Board member estimated that more than 30 percent of heavy trucks using I-10 through Tucson could be diverted on such a highway.
Doubters ask at what cost, in dollars and in environmental and aesthetic impact on largely undeveloped areas east and north of the Catalinas.
State transportation officials said it is too early to address such concerns.
No money is allocated to what would be a project costing hundreds of millions of dollars, no engineering plans have been drafted, and no definitive route has been drawn.
“This is just one of numerous studies that ADOT is doing around the state to evaluate long-term transportation needs,” Teresa Welborn, a spokeswoman for the state agency’s Tucson district office, said this week.
The agency accepted proposals from engineering consulting firms Wednesday for the feasibility and needs study.
The agency will make a recommendation for a consultant to the state Transportation Board early next month, Welborn said.
One local member of the state board thinks the idea has enough merit for additional study.
“It’s a concept,” S.L. Schorr, a Tucson lawyer and vice chairman of the board, said.
“The purpose would be to get interstate traffic off the downtown mainline,” Schorr said.
He noted that heavy truck traffic often is not bound for local destinations.
Those trucks, Schorr said, make up more than 30 percent of the traffic that rolls through Tucson’s downtown on the freeway.
A bypass would, at a minimum, draw enough traffic from I-10 in the metropolitan area to allow state transportation officials to delay future widenings of the freeway, similar to the $200 million project now under way to widen 1-10 to four lanes each way between 29th Street and Prince Road, Schorr said.
That project will take more than three years and will not be adequate to safely handle anticipated growth over the next two decades, transportation officials have said.
But building what would amount to another freeway on the north side of the Catalinas, possibly through the ecologically threatened San Pedro River Valley, has some conservationists aghast.
“Our concern is that it would quickly become a new growth corridor,” Greta Anderson, an ethnobotanist for the Center for Biological Diversity in Tucson, said this week.
The if-they-build-it-sprawl-will-follow concern is especially worrisome because the north and east sides of the Catalinas have been isolated without major improved roadways.
That has limited growth in an ecologically fragile and relatively pristine area.
The only existing road that might be incorporated into a new highway is the Park Link Drive that connects state Route 79 with I-10 north of Marana.
The San Pedro Valley is home to at least three endangered species: the Southwest willow flycatcher, the yellow-billed cuckoo and the delicate Huachuca water umbel aquatic plant, Anderson said.
Besides pollution that would be introduced to the area from vehicle emissions and petroleum-based runoff from the highway surface, extensive development of the area would impact the diminishing San Pedro Valley watershed, she said.
An abundance of archaeological sites have been found in the area, especially close to the life-giving waters of the San Pedro.
“The magnitude of the impacts it could have on the archaeology there is immense,” William Doelle, president of the Center for Desert Archaeology in Tucson, said Thursday.
Evidence of human settlement in the San Pedro area dates to the Clovis culture about 11,000 years ago.
Others settled in the area later, and the center has worked extensively on digs there since 1990, Doelle said.
Doelle worried that a new highway would spur the need for other roads to serve development, potentially obliterating sites still undiscovered.
“It would have the potential to wipe out a large part of the story of that past,” he said.
Such concerns were anticipated, Schorr said.
“We understand there are obvious environmental questions to address,” Schorr said.
Schorr said the highway could be designed and built as a limited-access route with relatively few exit and access ramps, except for some for services such as fuel and food.
“The idea is not to create commercial or industrial opportunities along the route,” Schorr said. “I don’t see development occurring along the route, except in some isolated areas.”
Should the consultant’s study, which would take about a year to complete, indicate that the highway is needed and feasible, and a funding source is identified, the state agency would consult with regional planning groups.
Those would include the Pima Association of Governments and the Maricopa Association of Governments, with the groups consulted on design and the roadway’s alignment, Welborn said.
For articles about the widening of Interstate 10, click here. Check it daily for project updates and traffic flow. E-mail news@tucsoncitizen.com and tell us about your daily drive: joys, pains, alternative routes.
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I-10 CONGESTION
Current traffic volumes on Interstate 10 in the Tucson metropolitan area:
● More than 150,000 vehicles daily
● At least 30 percent of vehicles are through traffic.
● About 62 percent are automobiles and light trucks.
● About 38 percent is heavy truck traffic.
● Each heavy truck creates congestion equal to five cars.
● Each heavy truck causes about 50 times as much pavement damage as a car.
Source: Arizona Department of Transportation
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THE CONCEPT
A conceptual route for an Interstate 10 bypass of Tucson and Phoenix. ADOT engineers have previously considered a bypass and dubbed it state Route 76.
● The bypass could split from Interstate 10 east of Tucson between Willcox and Benson.
● It might head to San Manuel, go west around the mine there, and connect with the already-existing Park Link Drive.
● The bypass could cross I-10 and run parallel about five miles to the south.
● It could cross Interstate 8 at Montgomery Road and cross state Route 347 south of Ak Chin.
● The bypass could head west and north, linking with I-10 west of Buckeye.
Source: Arizona Department of Transportation
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ON THE WEB
For more on the state’s highway system: www.dot.state.az.us
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