Workers set AASTO girders on a Grant Road structure.
The largest highway project in southern Arizona history — the widening of I-10 through downtown Tucson — is winding up six months ahead of schedule due to good cooperation between the partners and project accelerations.
Rod Lane, senior resident engineer with the Arizona Department of Transportation (ADOT) and ADOT project manager, credited cooperation between the city, the contractor and the highway department.
“All of us just worked really well together,” he said.
Kiewit-Sundt, a joint venture between the Phoenix office of Kiewit and Sundt Construction of Tempe, was the general contractor of 5-mi. (8 km) project from Prince Road to 29th Street. The project widened the highway to eight lanes (four lanes plus an auxiliary lane in each direction). Crews also replaced 16 bridges in the two-and-a-half year long project. Although the work that impacted traffic is complete and all lanes are now open, landscaping work will continue through spring of 2010.
What also helped the project sail to an early completion were accelerations along the way, Lane said.
“We looked for opportunities to accelerate it [the project],” he said. “Obviously anything we could do to move things up and move things along was what we did.”
One acceleration involved paving earlier than is usually done.
“We moved paving up a little by allowing the contractor to pave earlier — in other words in the heat when it was really, really hot,” Lane said. “But he had to do certain things to do that.”
To make it happen, ADOT “changed the specifications so it would work,” he said. “We had them cool it down and put on extra doses of lime water and they had to pave at night.”
That little bit of flexibility allowed the paving to be moved up an entire month, he said.
Although most of the time paving is off-limits until mid-Aug because it’s too hot for the materials, “we allowed them pave in July,” Lane said.
And when the contractor found himself muck-bound — unable to work because he had no place to move “a lot of earth” on the south end of the job — ADOT found a spot for him to store the dirt that would be used in the mechanically stabilized earth (MES) wall later so he could continue construction, he said.
“He had to excavate all this dirt and he didn’t have any place to put it,” Lane said. “Until that work space became available, we gave him a place to put it.”
There was good reason for the contractor to finish the project early — as an A + B project, an incentive is given for early completion — in this case a $920,000 bonus, Lane said.
The major challenge of the project was keeping traffic flowing — into, out of and around downtown Tucson — during construction.
When plans for the widening were announced, local business people were jittery. With the project running “smack in the middle of downtown Tucson” as Lane put it, and two and a half years of closures ahead, how would their clients and customers find their way to them?
To help quell the fears of the business community, ADOT sponsored “a big business outreach program to talk to them,” Lane said. “It actually ended up working out fine for them but they had some concerns in the beginning. There was a great deal of communication effort to keep them functioning.”
With the work being done downtown “we had to get people across the project from the east side to the west side or the west side to the east side — in other word, across the highway underneath it and then we also had to get people through the job,” Lane said. “Those were the big challenges.”
Shutting down the highway was not an option because I-10 is a major east-west route across the country, he said.
The roadway typically carries about 140,000 vehicles a day.”
“It’s pretty big,” Lane said.
Instead, ramps were closed limiting exits for motorists so ADOT created two “decision points” for travelers — one on the south end of the job and one on the north end of the job.
“So if you were coming in to the north end of the job, you had to decide if you were going through or if you were going downtown,” Lane said. “If you were going downtown, you had to get off up at the north end and drive the frontage roads all the way down. If you were going through, you just stayed in the main line and went through.”
That reduced the volume of traffic on the Interstate.
“Essentially we put half of the traffic on the frontage roads and half stayed going through so it allowed us to narrow the capacity at the top so we could build a half at a time,” Lane said.
“We got about a 60-40 split where 40 percent went through the main line and 60 percent roughly used the frontage roads. That’s how we were managed to split the traffic.”
To help motorists deal with the new traffic patterns ADOT built a $15 million interim traffic operations center prior to starting the work. “It essentially managed the traffic going through the project.” Lane said. “They controlled all the lights on the cross streets. We had seven cross streets and seven major intersections we had to manage the traffic through. That was all controlled by the traffic operations center.
“Everybody was terrified (when the project began) but after the first few months it kind of dialed in and everybody got used to it and it worked very well,” he said.
Weather was not a significant challenge, Lane said.
“We have the monsoons so we did have quite a few problems during the monsoon season,” Lane said.
Monsoons usually start at the end of May and continue until early August.
“Actually last year it was very dry so it didn’t impact us much at all,” he said. “We had some problems the previous year but they were minor. We were trying to pave and luckily it was nice and dry so we didn’t have any rain issues during that.”
While most of the equipment on the job was pretty standard, Resonant Machines Inc. of Tulsa used an unusual piece to “rubblize” the concrete of the old roadway, Lane said. The “rubblizer” was used to limit the impact of the work on some of the older residential neighborhoods the project crossed.
“We didn’t want to shake up those old buildings,” Lane said.
The number of workers on the job reached 300 at its maximum. “It fluctuated over time but at the peak it reached about 300,” he said.
“We did both remove and bring dirt in,” Lane said. “The overall project was a borrow project — we brought dirt in.”
The bridges replaced in the project were “straightforward bridges,” Lane said. “They were AASTO girders so they were precast bridges. The only thing that was unique was the artwork.”
As with all federal projects, 10 percent of the cost is allocated for art. On this project the art took various forms on the bridges some are embedded in the concrete while others “are actually form-liners where you cut the art and the design into the form liner and then you pour the bridge and you take the form away and suddenly this piece of art is left,” Lane said.
The art on each bridge has a different theme — one commemorates the University of Arizona’s participation in space travel and the lunar and Mars landings, another features the Harris hawk and another has a water theme. The south end of the job features more neighborhood themes because “a lot of the barrios down there participated so there were a lot of tile mosaics and local artists involved there,” he added.
The artwork by and large did not slow down the construction process, Lane said.
“We did have to go through and get the form liners right and there’s artistic interpretation and involvement in there. And it’s a little more expensive. Obviously it’s cheaper to build a nice flat face. Instead of having a flat face on a bridge or a flat bridge pier, we have ones with pictures of hawks on them and others with pictures of a river theme on them and so on,” Lane said. “It’s pretty nice.”
The art is on the bridges, visible to motorists traveling the cross streets under the highway.
Subcontractors on the project include Contractors West of Phoenix, Case of Chicago, and Combs Construction of Phoenix.
“Kiewick did all their own structural work, they did all their own earthwork, they did the MSD wall and they did just about everything else,” Lane said.