Ryan Stanton, rstanton@ExplorerNews.com
Dec. 7, 2005 - Several hundred members of the Marana community packed into Twin Peaks Elementary School Nov. 30 to hear the latest update on development of the Twin Peaks I-10 Interchange.
Planners of the $60-million project said construction could begin as early as 2007 with an ideal completion date of 2009, but they can't promise there won't be any hang-ups.
The environmental assessment process began in 2003 and is just wrapping up before an 18-month final design phase begins, said Harvey Gill, Marana's public works director.
"I would be (remiss) if I didn't tell you there was a potential for delay," Gill told the large audience during last week's meeting, adding that the public forum marked a major milestone in the project.
Marana is working with the Arizona Department of Transportation to develop design concepts and conduct environmental studies for the long-awaited interchange. Its completion will relieve traffic congestion in Continental Ranch where about 15,000 Marana residents live and funnel into daily backups at the Cortaro Road interchange.
The plans call for a new divided roadway that would connect Twin Peaks Road to Camino de Manana and Linda Vista Boulevard east of I-10. The four-lane extension of Twin Peaks Road includes two bridges across the Santa Cruz River, one for eastbound and one for westbound traffic.
Storm water runoff in the area and the potential risk of accidents at the railroad crossing on the east side of Interstate 10 led project officials to decide on constructing the road above the interstate and railroad tracks.
Bill Dehn, a project manager with URS Corporation, discussed the history of the project, citing as far back to the Continental Ranch Specific Plan of 1988, which acknowledged the need for another interchange in the area.
Marana's 1989 Master Transportation Plan and ADOT's 1990 design plans for I-10 reinforced the need for the interchange, Dehn said.
Project officials are proposing construction of several walls along neighborhoods west of the interchange to reduce traffic noise. In one case, a 17-foot wall would be constructed to buffer residents from noise coming from roadways that are destined to see significant increases in traffic, said Scott Stapp, a senior environmental planner with HDR, an engineering consulting firm.
"Obviously a 17-foot wall is going to change the way these folks look at the world," Stapp said, acknowledging that it would restrict their view of the nearby mountains. But those walls will be built unless residents show opposition, he said.
Walls ranging from 9.5 to 12 feet will be constructed along Linda Vista Boulevard east of Hartman Lane under the same circumstances, Stapp said.
"We're proposing to do that until we hear from the neighbors that they don't want that," he said.
Marana resident Mina Goldberg urged project officials to avoid building a wall adjacent to residential homes. She said the project instead needs to include a noise wall immediately west of the northern access road to prevent traffic noise from impinging on Continental Ranch residents north of Twin Peaks Road.
"Truck usage of the access road will be significant and noisy, will include trucks transporting gravel and cement and will likely involve shifting of gears, which, of course, adds to noise," Goldberg said, showing opposition to the current proposals.
"A moderate height wall next to the access road - just on the one side of that road - would accomplish what is needed to protect residents from access-road noise without impairing the visual aspects of their location," she said.
Planners aren't just looking at the effects of increased traffic immediately near the interchange, though. Noise studies around Arthur Pack Regional Park project a jump in noise levels, though Stapp said walls won't be constructed there because project officials don't think golfers will care much about the increased noise on the greens.
Six new traffic signals would be installed as part of the project, said Dave Perkins, a consultant with Kimley-Horn and Associates Inc.:
€ At the east and west frontage roads
€ At the intersection of Camino De Manana and Linda Vista Boulevard
€ At the interstate's access road
€ At the intersection of Twin Peaks Road and Coachline Boulevard
€ At the intersection of Twin Peaks Road and Silverbell Road
Marana has committed to resurfacing Twin Peaks Road through Continental Ranch with rubberized pavement to help keep noise levels down.
Stapp said the project includes acquiring 72 acres of right-of-way property, mostly private and some public. That includes land on 11 commercial properties amounting to 13 acres, he said.
Six species of animals that live in the project area were evaluated during environmental studies, two of which will be affected by the project. According to ADOT, the project is likely to affect the cactus ferruginous pygmy owl and the yellow-billed cuckoo, though not adversely, Stapp said.
Eight sites eligible for consideration by the National Register of Historical Places also are located within the project area, two of which will be disturbed: the Stewart Brickyard site and the original Casa Grande Highway.
Stapp said planners also tried to avoid relocating Tucson Electric Power utility towers and transmission lines, but they will have to be moved under the current plans. A Cortaro-Marana Irrigation District ditch between the frontage road and I-10 also will be turned into an underground pipe.
Jim DeGrood, Marana's executive assistant to the town manager, expressed optimism that the community showed up in support of the project. He said the environmental assessment process has taken longer than the town hoped, but he's pleased with the results so far.
"It took a fair amount of time," he said. "But I think it's a well crafted document that will only improve with the public comments we're receiving now."
The draft environmental assessment is available online at www.adotenvironmental.com and www.marana.com for review. The deadline for comments is Dec. 15, after which project officials will begin drawing up the final design plans for the interchange.