If built, the $6 billion to $8 billion roadway would skirt some of the region’s most important environmental areas. Detractors say a proposed Interstate 10 bypass would fracture the landscape west of town, including the sensitive Ironwood Forest National Monument and Saguaro National Park West.
Yet, state officials say that the sheer volume of traffic on I-10 warrants some sort of loop, and that routing one to the west of the present interstate — from the Vail area northwest to the Interstate 8 junction in Pinal County — remains the best way to relieve congestion.
By 2030, according to Pima Association of Government data, an estimated 154,621 vehicles will traverse I-10 daily in the Orange Grove Road area, with that number swelling to nearly 200,000 vehicles closer to downtown at St. Mary’s Road.
Even in the comparatively rural area near Pinal Air Park Road, according to the PAG data, by 2030 an estimated 84,411 cars will use the interstate — the only major route between Tucson and Phoenix and a vital cross-country trucking corridor.
Other options to alleviate the burden on I-10 around Tucson — double-decking portions of the road nearest town, expanding the road even more through town or running light rail through the city — are too expensive and won’t take enough cars off the road, according to state study on the I-10 corridor released in October.
A bypass that would weave around town, up through Avra Valley and to the Casa Grande area, remains the best choice, according to Arizona Department of Transportation.
The State Transportation Board will hold a public hearing on the proposal at 9 a.m. Friday, Dec. 19. The hearing will take place in Tucson City Council chambers, 255 W. Alameda St.
“Everybody is opposing,” said Pima County Supervisor Sharon Bronson. “I don’t know what ADOT is proposing.”
For more than a year, county officials have made known their staunch opposition to the proposed western bypass.
The county, and some federal officials, worry that the roadway would infringe on a 4.25-square-mile mitigation corridor that the Bureau of Reclamation purchased to help preserve mule deer. The animals use the area when crossing between the Tucson and Roskruge mountains.
In its study, ADOT has acknowledged the conflict there and suggested that a land swap would be needed to build the bypass.
“It goes through critical habitat,” Bronson said.
The supervisor said that on Friday and in the coming weeks, state officials should expect to get an “earful” from her on the plan.
Still, traffic will only increase as the region’s population increases. PAG estimates Pima County’s population will reach 1.5 million residents or more by 2030. And, according to Census projections, Pinal County’s population will approach nearly 2 million residents by that date.
“You just expand the existing corridor,” Bronson suggested as a way to alleviate future traffic congestion through the area.
The bypass would lie just outside Marana town boundaries.
“Marana supports the need for a future bypass of Tucson based on the information presented by ADOT,” Town Manager Gilbert Davidson said in a statement. “We’re letting the planning process run its course to determine an alignment.”
Town officials have some environmental concerns about the project.
And those concerns remain at the forefront today.
“Marana is concerned about the environment, and this is why the town is establishing a habitat conservation plan,” Davidson said. “Any road that comes through Marana would need to abide by our habitat conservation plan.”
So, the town has adopted a sort of wait-and-see attitude when it comes to the western bypass talks, spokesman Rodney Campbell said recently.
Another group, the Tucson Mountain Association, which promotes conservation efforts west of town at places like Saguaro National Park and the Tucson Mountain Park, remains skeptical of the state’s plans.
“I don’t see why we need to be putting these trucks on our west side,” said Judith Meyer, TMA board president. “We’re not happy about this … certainly we would fight for (wildlife) corridors.”
Still, Meyer noted, the state has yet to identify a funding source for the proposed bypass. And it could take years more of study and planning if such a road ever were to become a reality.