By Kim Noetzel / ADOT Communications

If you live, work or drive in north Phoenix, get ready to see changes on Interstate 17 at Pinnacle Peak and Happy Valley roads. The Arizona Department of Transportation’s traffic interchange reconstruction project is taking shape from the ground up.

Work on the $50 million project began in November 2018 and has so far included roadway work, utility relocations, installation of underground pipes, building up the embankments and replacing the drainage culvert east of I-17 at Pinnacle Peak Road.

This month, crews began constructing the footings and abutment walls for the new bridge that will carry westbound traffic over I-17 at Pinnacle Peak Road. Pouring concrete for the 19-foot-tall pier columns that will support the new bridge are scheduled by month’s end. As these recent photos illustrate, cranes are moving forms into place as iron workers carefully assemble the rebar cages for the foundations, abutment walls and piers.

Once these vital bridge support structures are in place, the project team plans to place the westbound bridge girders in mid-May. The concrete girders are the horizontal support beams onto which the 258-foot bridge deck will be constructed.

With the bridge deck in place by late summer, crews plan to switch traffic onto the new structure, demolish the existing Pinnacle Peak Road bridge, and then build the eastbound Pinnacle Peak Road bridge over I-17.

At the same time, construction activity will ramp up at Happy Valley Road, where a new diverging diamond interchange will replace the two-lane bridge and roundabouts on the east and west ends.

In the coming weeks, drivers should expect continued lane restrictions in the project area. Beginning in May and continuing through November, at least 14 full closures of north and southbound I-17 in the project area are scheduled to occur on weekends. Crews also will work week nights on the cross street bridges. ADOT will provide specific information about upcoming restrictions and closures as it is finalized.

To learn more, and to subscribe for project updates and traffic alerts by email, visit the project webpage.

By Kim Noetzel / ADOT Communications

Drivers who use Pinnacle Peak Road at Interstate 17 will soon experience the first major impact of the $50 million project to reconstruct two overburdened traffic interchanges in north Phoenix. A section of Pinnacle Peak Road directly east of I-17 is scheduled to close for 23 days as crews remove and replace a drainage box culvert beneath the roadway.

The closure is scheduled to be in place around-the clock from early Tuesday, Feb. 19, until the early Thursday, March 14. Drivers who rely on Pinnacle Peak Road in the area will need to use alternate routes and, for those 23 days, allow plenty of extra travel time because of heavier-than-usual traffic. Learn more about detour routes.

Removing and replacing a concrete culvert can be a large and complicated endeavor. Culverts come in different shapes and sizes depending on various factors, such as location and climate. They function as cross drains, allowing water to flow under a road, highway, railroad or other man-made obstruction from one side to the other. You probably haven’t thought much about – or even noticed – the box culverts situated just below the streets and highways you drive on every day because, let’s face it, they aren’t terribly exciting.

That is, until it’s time to replace a really big one made from reinforced concrete and steel and nearly as long as four semi-trucks.

The culvert under Pinnacle Peak Road at I-17 is 6 feet high, 8 feet wide and a whopping 199 feet long. To remove it, crews need to work carefully beneath the roadway where they’ll break up the existing concrete-and-steel structure into smaller sections and haul it all away. At the same time they’ll build a new box culvert in its place – even wider and longer – to accommodate the new tight-diamond traffic interchange being constructed at I-17 and Pinnacle Peak Road.

There is light at the end of the tunnel (or culvert, in this case). With the larger culvert in place, ADOT can then build the new I-17 interchange at Pinnacle Peak Road that features two through lanes in each direction; two dedicated left-turn lanes; dedicated right-turn lanes; and bicycle and pedestrian walkways. See a before-and-after image of the existing interchange compared to the new one.

After work is done at Pinnacle Peak Road, the project will shift to I-17 and Happy Valley Road, where plans call for removing the roundabouts and building a diverging diamond interchange. Removing the roundabouts also promises to be no small feat, so stay tuned for another blog when this project reaches that long-awaited milestone.

By Doug Pacey / ADOT Communications

Tell someone you work at the Arizona Department of Transportation and you’re bound to hear a story or two or an earful about a personal experience with highways, the MVD or those weird safety messages. These anecdotes often come at the most unexpected times.

That was the case Friday morning when I stopped at a drive-thru coffee stand across the street from Arizona State University’s Tempe campus. Making small talk with a young woman working there, she asked where I worked. When I told her, “ADOT,” her eyes widened and she excitedly told me how on her drive to work that morning on Interstate 17 she saw an overhead message board switch from displaying travel times to warning of an oncoming wrong-way driver. She’d never seen that before, she said, and immediately took the next exit where she saw a few police cruisers entering the highway.

We talked about the year-old thermal camera wrong-way detection system on I-17 and how it works, alerting law enforcement and other drivers to wrong-way vehicles. In fact, the system detected two wrong-way vehicles entering I-17 that morning. The first came at 3:15 a.m. at McDowell Road and the other at 4:29 a.m. at Dunlap Avenue. Both vehicles appeared to have self-corrected on the ramp before reaching the mainline.

She wondered, though, why so many other vehicles didn’t exit the highway when the message displayed. It’s a good question and conversations like this tell us a few things. First, we still have more work to do promoting the “Drive Aware, Get There” safety campaign geared toward helping people avoid wrong-way drivers. Second, the work we do to make highways safer affects every one of us, often when we least expect it. Know that we’ll continue to seek out countermeasures that will help reduce the number of traffic fatalities and serious injuries that occur each year.

By David Rookhuyzen / ADOT Communications

Just in time for holiday travel, ADOT is giving drivers on Interstate 17 an answer to the eternal questions of “When will we get there?” and “How much longer?”

Those traveling between Phoenix and Flagstaff now see estimated travel times to their destinations on our digital message boards, something Valley motorists have enjoyed for decades. This test display now shows how long it'll take to reach destinations such as Cordes Junction, Prescott, Sedona and Flagstaff.

But these travel times are more than just a nifty feature or a way to keep people in the back seat complacent. During winter weather or when incidents cause delays, these signs can help drivers make informed decisions on the best route to take to get to where they are going. Delays due to a crash might have a northbound I-17 driver decide that State Route 260 is the best way to get to Sedona or a southbound driver determine State Route 69 will get them to Prescott faster than State Route 169.

Real-time data for the traffic times come from INRIX, a mobility analytics company that helps transportation agencies monitor, measure and manage traffic information. This is different from how travel times are estimated in the Valley, using ADOT’s in-pavement traffic-flow sensors. ADOT designed a software application to automatically process INXRIX’s data for I-17, with the upside being that it could eventually be expanded for use on other busy state routes.

By David Woodfill / ADOT Communications

It's an Arizona mystery as enduring as the Lost Dutchman's Mine, the Phoenix lights and fate of the Hohokam.

Who ... or what ... decorates the Mystery Tree every year on I-17 near Sunset Point Rest Area?

Is it these guys?

Or this guy?

Perhaps it's one of Santa's elves.

Whoever the jolly culprit is, the annual tradition has brought holiday cheer to Arizona motorists for years.

Equally mysterious is how the 20-foot-tall tinsel- and garland-spangled juniper survives brush fire after brush fire. To the right is a photo from 2011 and shows nearly all the nearby vegetation burned.

The tree, however, stands unscathed.

That's a holiday tale fit for a Charles Dickens book or Macaulay Culkin movie!

Nah, it's probably aliens.

By Doug Nintzel / ADOT Communications

The Arizona Department of Transportation’s wrong-way vehicle alert system being tested along a stretch of Interstate 17 in Phoenix has earned a special award for innovation.

ADOT’s first-in-the-nation pilot I-17 system, featuring 90 thermal cameras that detect and track wrong-way vehicles, was named the “Best in Class” winner in a Government Innovation Awards ceremony in Washington, D.C.

The system, in operation since January of this year, has detected more than 40 wrong-way vehicles within the I-17 pilot project’s boundaries stretching 15 miles from the I-10 “Stack” interchange near downtown Phoenix to the Loop 101 interchange in north Phoenix.

Brent Cain, who leads ADOT’s Transportation Systems Management and Operations division, and David Riley, the I-17 system's project manager (shown in the photo above), accepted the award recently during a ceremony held by GCN, an information technology industry magazine and sponsor of the innovation awards competition.

“To earn a best in class award while sharing the evening’s event with agencies like the U.S. Navy, NASA and the FBI was very humbling,” Cain said. “This award recognizes the commitment of many people at ADOT as well as our private sector partners to reduce the risk of tragic wrong-way crashes, often caused by impaired drivers.”

ADOT’s I-17 system immediately alerts operators in the agency’s traffic operations center as well as the Arizona Department of Public Safety to the detection of a wrong-way vehicle, saving valuable response time for AZDPS troopers in the field and allowing ADOT to quickly post warning messages on overhead signs for other freeway drivers.

Fortunately, the vast majority of wrong-way drivers detected by the system’s thermal cameras so far have turned around on off-ramps without entering the freeway.

ADOT earned the Best in Class innovation award in the state and local category. The U.S. Navy won best in class in the defense category while the U.S. Department of Health and Human Services was recognized among federal-civilian finalists.