Go with the flow: Overhaul aims to modernize I-17/Cordes interchange
PRESCOTT - As drivers approach the Cordes Junction/Interstate 17 interchange from the east, their confusion is palpable.
During the lunch hour one day this past week, car after car chose the wrong turn lane while exiting onto I-17 from the Cordes Junction community.
"That is a perfect example of why this project is needed," said John Hall, resident engineer for the Arizona Department of Transportation (ADOT), referring to the mammoth interchange overhaul that is under way at the intersection of I-17 and Highway 69 at Cordes Junction.
Although the driver was in a left-turn lane that was clearly marked as the lane for northbound I-17 traffic, he ended up making a slow, wide turn in the other direction. Several minutes later, another driver made the same mistake.
ADOT officials acknowledge that the interchange as it currently stands is a bit convoluted. Drivers exiting from Cordes Junction must turn south to head toward Flagstaff, while those heading toward Phoenix must exit to the north.
"A lot of this is a unique design," Hall said as he surveyed the evolving interchange. "I've never seen another one like it."
Dating back to the 1960s, the existing Cordes Junction interchange became less and less effective as the traffic increased. Currently, ADOT numbers indicate that about 28,000 vehicles pass through the interchange on I-17, with another 13,000 coming from Highway 69.
The interchange underwent years of study and design before ADOT kicked off the $51 million overhaul in August 2011.
Modern standards called for more bridges and more delineation of through-traffic from local traffic, ADOT officials said.
The new design will incorporate a "diamond" design that will include seven bridges and two roundabouts, and will allow drivers to more easily choose between through-traffic and local traffic.
Through-traffic exiting onto Highway 69 will be able "flyover" the interchange without delays, according to ADOT, and new local roads will allow for better access to area businesses and homes.
The overhauled interchange will also provide longer ramps for acceleration onto I-17. ADOT Public Information Officer Dustin Krugel noted that one of the weaknesses of the current configuration is the short distance for merging into the fast-moving interstate traffic.
The project is no small endeavor. It currently encompasses about 17 acres of construction and is the largest state project in Northern Arizona.
The general contractors - a collaboration of Vastco, Inc., and Sundt Construction - have about 100 employees on hand, with more working for sub-contractors. ADOT Senior Community Relations Officer Tricia Lewis noted that about half of the construction workers are local.
While the project will include massive amounts of concrete, it will incorporate an aesthetic component, with the designs of world-renowned artist, architect and urban planner Paolo Soleri.
On the abutments, wing walls and retaining walls throughout the project, Soleri's soaring designs will be reminiscent of the architectural shapes in his nearby Arcosanti.
Mary Hoadley, Arcosanti site coordinator, noted that Soleri spent about three years on the design and went through several versions before coming up with the current plan.
The semi-circular designs that bring to mind sunrises and sunsets "are shapes that refer to shapes in his architecture," Hoadley said, adding that the designs are at three different depths, which will lend a three-dimensional look.
While the designs currently are still in concrete, Hoadley said the finished product would incorporate shades of yellow, blue, black, walnut brown, and a creamy off-white.
During its first seven months of construction, the interchange project has required a number of traffic interruptions on the busy I-17. But Lewis and Krugel emphasized that the road closures have occurred during the nighttime hours, when traffic is at its lightest.
Hall said the contract requires that traffic interruptions must take place between 7 p.m. and 6 a.m., Mondays through Thursdays, and from 11 p.m. to 6 a.m. on Sundays. The contract does allow for closures at other times, with permission from ADOT, but Hall said no such closures have occurred so far.
The closures of as long as 30 minutes have caused traffic back-ups on the interstate, Hall said, but the back-ups have cleared within about seven to 10 minutes.
Lewis said the Cordes Junction community has been involved throughout the planning and construction of the project, and ADOT has worked to get the word out through newsletters and emails.
Among the most noticeable of the project's changes will be the replacement of the Big Bug Bridge. Crews have removed part of the old bridge and are working on its replacement.
Instead of the traditional design-bid-build format, ADOT is using the "construction-manager-at-risk" arrangement, which brought the contractor on board while the design was still under way - about a year before the construction started. The format also called for both sides to agree to a "guaranteed maximum price" of about $51 million.
ADOT expects the project to be complete by June 2013, and officials say the work is on schedule.