Paving in the Pines
By K. Robert Wendel

State Route 260 is known as an escape route to Arizona's Rim Country, and in the summers, it is jammed as refugees from the heat head for the hills

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The stretch of S.R. 260 between Payson and Heber is also known for its dangerous curves, lack of passing lanes and the ever-present possibility of hitting an elk.

"It (S.R. 260) has been improved as traffic volumes have increased, but the road doesn't meet the current safety standards," said engineer Bill Pearson, Arizona Department of Transportation acting resident engineer.

And safety is the primary reason a multi-year project in under way to upgrade the roadway. The road is part of the >> federal evacuation route in case of national emergency from Show Low to Holbrook, and in the next two decades the now two-lane highway will be brought up to federal standards with a four-lane divided highway.

The Arizona office of D.H. Blattner and Sons completed the first project section in 2003 with a bridge over Preacher Canyon, east of Payson. Crews from Arizona office Kiewit Western Co. wrapped up their work on a 5.5-mi. section of S.R. 260 near Christopher Creek last summer.

Crews from the Phoenix office Edward Kraemer and Sons Construction are nearing completion on the latest section of road, a 3-mi. segment near Kohl's Ranch. Crews are constructing three precast girder bridges; two post-tensioned, cast-in-place box girder bridges; and excavating 1.2 million cu. yds of rock.

Arizona firms KLB Contractors is the excavation contractor, and Paradise Rebar is tying the structural rebar.

Contractors will use 14,000 cu. yds of concrete for the bridge and miscellaneous structures and 50,000 tons of asphalt in three, 2.5-in. lifts on top of 6- in. of decomposed granite. FNF Construction of Tempe is the paving subcontractor.

Kraemer started the $23 million project in August 2003 and plans to finish the job in July.

One of the key features of the road projects are wildlife underpasses. Two of the bridge structures on the Kraemer job are designed as wildlife crossings, but their designs have had to change.

"A.D.O.T. noticed the elk didn't like this design," said Kraemer project manager Tim Hutton. "It created a box canyon effect, which is a natural way that elk can be ambushed by mountain lions. The elk would get halfway through the structure and run out."

Builders and designers took out the mechanically stabilized earth wall system and replaced it with taller abutments that are spread wider, eliminating the box canyon effect.

Engineers are also working to preserve the character of the area, with massive erosion control plans and a strict environmental plan regulated by the U.S. Forest Service and the Arizona Department of Environmental Quality.

The area's lack of water limits major construction to one job a year, but A.D.O.T. teamed with AMEC Earth and Environmental of Phoenix to build a 14-mi. pipeline from the Payson well fields to the project site. But with all the rain in the area over the last seven months, contractors are putting water back into the system this year rather than taking it out.

"Water is a premium in that area because there's just not a lot of it," said A.D.O.T. engineer Tom Foster. "When the Tonto Creek reaches a certifiable high flow, we take the excess water and pipe it to the well field and inject it into the ground."

The project also will help Kohl's Ranch residents. Since S.R. 260 ran straight through the area, summers were a nightmare of traffic and congestion for locals.

"People in the community bought their homes to maintain a slower lifestyle," said Berwyn Wilbrink, a project manager with road designer Jacobs Civil Inc. of Phoenix. "You have a nice little wooded area, and the residents don't like the idea of a freeway running through it."

The Kohl's Ranch and Christopher Creek projects bypass the two areas with a road alignment east of the towns.

The projects are part of a larger plan that will see 50 mi. of new road built between Payson and Heber, with the state allocating $216 million spread over the next 17 years.

"The goal is to get everybody from Payson to the top of the rim on four lanes," said A.D.O.T. resident engineer Myron Robison.

The Christopher Creek project and Kohl's Ranch project are the second and third in a long series of projects for the road reconstruction. The projects have been a long time coming, with engineers starting construction documents more than 15 years ago.

The new road will be a vast improvement over the existing route, with plans calling for broad shoulders, better visibility and a quieter road with the application of rubberized asphalt. Much of the old S.R. 260 will be abandoned and returned to its natural state.

"The intent is to have a divided highway, primarily for safety, but a divided highway also allows each roadway to avoid a freeway appearance and blend in with the topography of the forest," Wilbrink said. "We want to give the driver the experience of being in a forest and not on a freeway."