Shining the light on a safety improvement project on the SR 80 tunnel near Bisbee

Shining the light on a safety improvement project on the SR 80 tunnel near Bisbee


Shining the light on a safety improvement project on the SR 80 tunnel near Bisbee

Shining the light on a safety improvement project on the SR 80 tunnel near Bisbee

By Garin Groff / ADOT Communications
April 12, 2024
A work truck is parked inside a tunnel as construction work occurs inside the tunnel.

It’s time to shed some light, literally and figuratively, on a highway safety project just outside of Bisbee.  

That’s because work is underway to install LED lighting on the Mule Pass tunnel that carries SR 80 traffic into this southeastern Arizona locale popular with tourists.

Recent photos, including the one above, show work crews have started work by installing conduit that will soon power the new lighting.

The lighting isn’t the only improvement, as ADOT has also changed the lane configuration. We eliminated a passing lane to create room for shoulders on each side of the roadway, with one lane of travel in each direction. 

Drivers can expect work and possible lane restrictions Mondays through Fridays from 10 a.m. to 4 p.m. The project will be complete this spring.

For more information, please visit the project page for the SR 80 Mule Pass Tunnel Safety Project.


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One year in, US 93 widening project in Wickenburg now 80% complete

One year in, US 93 widening project in Wickenburg now 80% complete


One year in, US 93 widening project in Wickenburg now 80% complete

One year in, US 93 widening project in Wickenburg now 80% complete

By Garin Groff / ADOT Communications
March 12, 2024
Heavy equipment works in a highway construction area as other vehicles drive by.

After one year of construction, a project to widen a 5-mile segment of US 93 in Wickenburg has reached an important milestone: It’s now approximately 80% complete.

With the project this far along, we figured it’s a good time to look at what we’ve accomplished and what kind of changes drivers can expect as they navigate through this active work zone.

Crews have built temporary lanes along US 93 so traffic can be shifted over to one side of the highway, allowing work to begin widening the other side of the roadway. Also, crews have completed a concrete box culvert that provides drainage for the Amir Wash under the Tegner Street extension to Rincon Road.

This month’s paving work will begin on the new northbound lanes that are being constructed adjacent to the existing roadway. Traffic impacts are expected to be minimal for that work.

No restrictions are anticipated during the day, weekends or holidays to minimize delays for drivers.

Wickenburg Town Manager Stephen Erno impressed by what he has seen thus far.

“ADOT has effectively managed temporary lane closures, restrictions and overall (project) timelines, thereby minimizing traffic disruptions through our town,” said Erno. “Most of all, despite initial concerns about the magnitude of this project, complaints have been minimal from residents.”

The $51 million widening project is part of ADOT’s long-term vision to transform the entire 200-mile section of US 93 from Wickenburg to the Hoover Dam bypass into a modern four-lane divided highway. ADOT has invested nearly $500 million in improvement projects on this corridor in the past several years.

Construction is expected to continue through summer and includes:

  • Raised center medians
  • Frontage roads
  • Roundabouts at Rincon, Cope, Vulture Mine and Scenic Loop roads
  • Lighting, drainage systems and erosion control

For more information, please visit the project web page at

A little sleuthing reveals history behind an ‘unknown’ highway improvement

A little sleuthing reveals history behind an ‘unknown’ highway improvement


A little sleuthing reveals history behind an ‘unknown’ highway improvement

A little sleuthing reveals history behind an ‘unknown’ highway improvement

By Steve Elliott / ADOT Communications
May 24, 2023
A black-and-white photograph of a highway model of a traffic circle.

When time permits here at the ADOT Communications factory, I like to dive into the State Library, Archives and Public Records Arizona Memory Project and look at old photos of highway projects, equipment, people, etc. 

The other day, I came upon the photo above, dated 1942, with a heading that made me a little sad, then curious: Highway model for an unknown Arizona highway.

People obviously put a lot of thought and effort into the highway improvement depicted in the model. So I set about solving the mystery of this “unknown” highway improvement, including whether it was built and, if so, whether it’s still around. 

I’d like to pretend it took a lot of sleuthing, but I spotted “Warren” with the arrow pointing right and solved this mystery in a couple minutes using the Google Machine.

The model shows what 80-plus years later is commonly referred to as the Bisbee roundabout (a.k.a. Lowell traffic circle, after Bisbee’s Lowell district) in southeastern Arizona. It’s at the intersection of State Route 80, State Route 92 and Bisbee Road, between the Lavender Pit and Bisbee’s Warren district. You can view the real thing on Google Maps and even take a virtual drive via Street View. Or you can go to Bisbee, which is a neat and pretty place.

On Feb. 1, 1946, The Associated Press reported that the Arizona Highway Department was soliciting bids for a Lowell traffic circle “long sought by Bisbee and Douglas citizens.” Two weeks later, AP reported that Packard Contracting Co. submitted the low bid of $394,932.15. “The Lowell traffic circle is an engineering method of relieving traffic congestion on the Bisbee-Douglas highway near Lowell,” the article said. 

Despite my best efforts, I found no articles or state documentation saying when the contractor completed this improvement. But I did find Lowell traffic circle mentioned in newspaper advertisements and articles as early as 1949.

That’s quite a bit of history for something filed as “unknown.” And now that's changed. Based on this blog, I've had the most wonderful correspondence with the good people behind the Arizona Memory Project, and this photo now carries the title: Model of Lowell Traffic Circle in Bisbee Arizona


A GIF comparing a traffic model with an aerial view of the constructed roadway.

Pardon our dust, we’re moving that bridge in Florence

Pardon our dust, we’re moving that bridge in Florence


Pardon our dust, we’re moving that bridge in Florence

Pardon our dust, we’re moving that bridge in Florence

By Garin Groff / ADOT Communications
January 20, 2023

This new bridge might seem unimpressive because it’s only one lane, but it’s got one unexpected trick up its sleeve.SR 79 bridge slide construction

It was built to travel -- at least a few feet -- and that’s what it’s going to do this weekend, Jan. 20-23.

Yes, ADOT is moving this new smallish concrete roadway section as part of an innovative way of replacing a bridge by sliding it into place, piece by piece. The process is continuing as we work on the second and final weekend of moving the structure’s components on State Route 79 in Florence.

Last weekend, Jan. 14-15, crews slid five of these segments into place to make up the northbound lane. And this weekend, we’ll move five sections of the southbound lane. Each segment spans 300 feet in length -- that’s as long as a football field. 

We’ve already discussed how the bridge slide process works, but we’d like to offer a final reminder about his weekend’s activity. And that the work will mean travel delays.

Traffic at the bridge over the Gila River will be narrowed to a single lane of alternating travel, regulated by a temporary signal. The restriction is planned from 8 p.m. Friday, Jan. 20, through 5 a.m., Monday, Jan. 23.

By Monday morning, Jan. 23, all sections of the new bridge should be in their permanent home and taking one lane of traffic in each direction.

Drivers should expect occasional but minor restrictions in the next few months as work crews wrap things up. Once all the dust has settled, the new, 1,500-foot-long bridge will feature one travel lane in each direction, 8-foot-wide shoulders and a protected pedestrian walkway.  You can find out more about the work on the SR 79 bridge replacement project page

Let's talk pavement preservation - and why you'll see it this summer

Let's talk pavement preservation - and why you'll see it this summer


Let's talk pavement preservation - and why you'll see it this summer

Let's talk pavement preservation - and why you'll see it this summer

By David Rookhuyzen / ADOT Communications
June 21, 2021

You may hear this phrase often, especially during the summer. 

"Drivers should prepare for some delays on this state highway due to pavement preservation work between this and that milepost."

Maintaining state highways and freeway is a full-time gig for us. In fact, the tentative 2022-2026 Tentative Five-Year Transportation Facilities Construction Program even has $1 billion allocated for pavement preservation over the next five fiscal years. 

But what exactly do we mean when we say "pavement preservation?" 

To answer that question we turned to Andrew Roth, the assistant district engineer for ADOT's Northwest District. He broke down for us the major types of pavement preservation work crews get up to this time of year. In order of ascending cost we have:

Fog seal: This is the most common type of pavement maintenance. As we explained in an earlier blog post, fog seals contain emulsion – remember that's asphalt binders and water – onto a road to rejuvinate the asphalt and restore lost flexibility to the roadway surface. As Roth explained, the sun causes paving to start oxidizing, and fog sealing helps keeps that oxidization from getting into the deeper, structurally significant part of the road. 

Chip seal: We've told you about chip seals before, where aggregate (crush gravel) and an emulsion (asphalt binders plus water) are laid down together to form the new top road surface. Turns out though that there are two different types of chip seal. The first is what we just described. The second is known as a hot application, where different, heavier asphalt binders are sprayed on the roadway surface at temperatures between 350 and 400 degrees Farenheit and covered with chips that are pre-coated in asphalt. 

Slurry seal: This type of pavement preservation involves an emulsion, aggragate and a bit of dry-powder cement which is mixed in a specialized machine. The mix looks like chunky chocolate milk, Roth said, and looks brown on the road until it cures, when it looks like typical black asphalt. A slurry seal is especially good at sealing up cracks and keeping out water.

Micro-seal: Finally we come to the micro-seal, which is a lot like a slurry seal, but here you are getting into some heavy-duty chemistry, as the asphalt binders in the emulsion have different polymers so it acts different. A micro-seal can also be used to fill ruts, which alleviates any issues with water collecting on the road.

There also is something called a "cape seal," which is basically a chip seal covered by a slurry seal or micro seal. 

So those are the different types of pavement work you can expect to see while out on the road this summer. But there's a good reason why you see it while it's summer. Paving needs a specific temperature range that, depending on the work being, done cannot be either too cold or too hot. For example, a chip seal can only be applied when the pavement surface temperature is at least 85 degrees and the air temperature is at least 65 degrees and rising. A chip seal application must stop once the air temperature is 70 degrees or less and falling, while a slurry seal may be applied when both the pavement and air temperatures are above 45 degrees and rising. It has to stop if either the pavement or air are below 55 degrees and falling. And a hot application chip seal can't be done if the daytime air temperature will exceed or are forecast to exceed 110 degrees the day before, the day of or two days after it's applied. 

Furthermore, these treatments cannot be applied if rain is forecast within 24 of the pavement work. The same is true if there is the possibiity of freezing weather forecast, Roth said. 

That means paving work usually has fairly narrow time windows when it can be done, which become more narrow as you rise in elevation. 

As you might expect, one the most important elements for pavement preservation is having the right temperature range and plenty of sunshine. Those help evaporate the water used in the asphalt emulsion, which allows the pavement to cure properly. As we explained in an earlier blog, this is one of the major reasons for doing paving work during the day. While some of this could be done at night, and is under special circumstances, without daytime highs and sunlight, it takes much longer for the road surface to be ready for the driving public again. 

"It's a lot of artwork when it comes to applying these pavement treatments because of all the elements you are trying to monitor that drive construction," Roth said. 

We want your opinion as we map out years of highway improvements

We want your opinion as we map out years of highway improvements


We want your opinion as we map out years of highway improvements

We want your opinion as we map out years of highway improvements

By Garin Groff / ADOT Communications
June 2, 2021

When ADOT plans highway improvement and maintenance projects, we turn to experts in engineering, traffic studies, planning and more – but there’s one more expert we need to hear from.

And that expert is you. Afterall, who knows more about Arizona’s highways than the motorists who travel on them everyday?

So please help us with our blueprint for improvements, which we’ve outlined in the 2022-2026 Tentative Five-Year Transportation Facilities Construction Program. It’s our yearly update on which design and construction projects will move forward and with what kind of funding, and an important part of it is getting your opinions.

But time is running out, with the deadline to provide input coming today, Thursday, June 3, at 5 p.m. We began asking for feedback when the process began in March, and more than 900 of you have submitted feedback online, at public hearings, through the mail or by phone.

The plan includes a lot of details on projects across Arizona, but here’s a quick glimpse of it: More than $1 billion in pavement preservation projects are planned over five years, including upgrading 581 lane miles of pavement from fair and poor condition to good condition.

The tentative plan also includes new lanes on I-17 between Anthem and Sunset Point, widening US 93 near Wickenburg, replacing the Gila River bridges on I-10 between Phoenix and Casa Grande, and building the first phase of the I-40/US 93 interchange in Kingman.

We encourage you to look over the plan and reach out to us in any one of the ways we’ve listed here. We look forward to hearing from more of you!

North to south, east to west, ADOT investing in road preservation

North to south, east to west, ADOT investing in road preservation


North to south, east to west, ADOT investing in road preservation

North to south, east to west, ADOT investing in road preservation

By Ryan Harding / ADOT Communications
June 1, 2021

Much like vehicle maintenance, regular road maintenance is needed to keep highways in good functional condition. ADOT continually invests in maintenance of highways and state roads across Arizona that serve countless commercial trucks and passenger vehicles every day.

In fact, ADOT spent more than half a billion dollars (yes, billion with a “B”) on pavement preservation projects alone in a five-year period from 2016 to 2020.

The paving projects during this period covered the state from SR 389 in Fredonia near the Utah state line to SR 92 in Sierra Vista and Business 19 in Nogales; and from SR 95 in La Paz County to US 191 and US 163 in the Navajo Nation and SR 75 in Greenlee County and everywhere in between.

Steve Boschen, director of ADOT’s Infrastructure and Delivery Operations Division, acknowledges the importance of these kinds of maintenance projects saying, “This is an important investment that we make each year to help keep traffic and commerce flowing in and around the state.”

He added how even these basic maintenance projects help achieve ADOT’s True North of safely home for every driver.

And ADOT will continue to invest in maintenance of Arizona’s highway infrastructure. In fact, another pavement project is starting in Show Low this month. This project will repave a total of 11 miles of US 60 and SR 260 in Show Low. For more information on that project, visit

In addition to state roads, ADOT has also administered dozens of paving projects to help maintain local streets in communities across Arizona.

Watch us make a new bridge, and maybe a future bridge builder

Watch us make a new bridge, and maybe a future bridge builder


Watch us make a new bridge, and maybe a future bridge builder

Watch us make a new bridge, and maybe a future bridge builder

By Garin Groff / ADOT Communications
May 24, 2021

If you drove by Interstate 10 in far east Tucson on a recent Monday night, you couldn’t have overlooked a massive boom pumping concrete onto the new Houghton Road overpass.

But we wanted to share something you couldn’t have seen while zipping through the area: A little father-daughter bonding at what was dad’s office that night.

Meet Jeremy Moore, the Assistant District Engineer for ADOT’s Southcentral District, and his 11-year-old daughter, Kailey (both featured in the video and photo on this page!). 

Moore oversees the interchange reconstruction project and figured this busy work site was a perfect place for his daughter, who is eyeing a career in some kind of engineering or architecture. Kailey loves structures, so what could be better than watching part of a 12-hour, overnight operation to pour 1,000 cubic yards of concrete that now form the bridge’s future driving surface.

Kailey is a sixth grader at St. Joseph Catholic School in Tucson who has a passion for Taekwondo – she’s a second-degree black belt – and loves engineering, technology, science and math.

Thankfully for Kailey, there was a lot of math to soak in!

Her father shares a few interesting numbers on all that concrete. It’s:

  • 1,626 tons
  • 803 cubic yards
  • held together with 123 tons of reinforcing steel
  • forming a structure that’s 245 feet long, 125 feet wide and 8.5 inches thick

If Kailey ever decides to build something like a bridge, she got the perfect lesson under the stars that Monday night.

As to the project and what it means to drivers, this concrete pour represents a milestone. The entire bridge deck was poured in just one night, which means crews can plan for shifting traffic onto that new structure later this summer. That in turn allows us to demolish the old two-lane Houghton Road bridge and complete the ramps on the east side of the interchange.

And a few more numbers to finish with: The $24.4 million project is expected to be complete in about 7 months – at the end of 2021. Expect some nighttime and weekend lane restrictions, which could lead to delays of about 15 minutes.

275 million reasons ADOT knows the value of Interstate 40

275 million reasons ADOT knows the value of Interstate 40


275 million reasons ADOT knows the value of Interstate 40

275 million reasons ADOT knows the value of Interstate 40

By Ryan Harding / ADOT Communications
May 18, 2021

How do we love Interstate 40? Let us count the ways. 

1...2...275 million!

That’s how many dollars ADOT has invested in the I-40 corridor over the last five years. From minor bridge repairs to complete bridge replacements and small pavement patch jobs to miles-long pavement replacement projects, we see the value I-40 brings not only to Arizona but the rest of the country.

Since 2016, ADOT has replaced pavement on about 90 miles of I-40 and repaired, upgraded or replaced 35 bridges along I-40. 

The agency utilizes innovative techniques to cut I-40 bridge replacements by months like the bridge slide method or a process known as a geosynthetic reinforced soil-integrated bridge system to rebuild bridges, creating new abutments that integrate into the roadway with a reinforced soil foundation.

We’ve replaced dozens of bridge decks and even rebuilt 5 miles of I-40 in each direction near Williams.

Bridges and road surfaces aren’t the only things to be improved over the last five years. In continuing to support commerce, ADOT has made improvements to rest areas along I-40 including Haviland Rest Area west of Kingman and Painted Cliffs Rest Area near the New Mexico state line. Improvements are currently underway at Meteor Crater Rest Area. 

Truck parking was also permanently expanded by nearly 100 spaces at the Haviland and Meteor Crater rest areas last year.

And most importantly, we’re not done! Work along the I-40 corridor continues today. Crews are replacing pavement along 10 miles of I-40 from I-17 to Walnut Canyon Road. ADOT is also currently improving 16 bridges spread out along the interstate from California to New Mexico.

Looking toward the future, ADOT is in the process of planning a new traffic interchange between I-40 and US 93 in west Kingman  as well as more pavement replacement projects west of Ash Fork.

'Big Foot' former director left big transportation legacy

'Big Foot' former director left big transportation legacy


'Big Foot' former director left big transportation legacy

'Big Foot' former director left big transportation legacy

By Laurie Merrill / ADOT Communications
May 4, 2021

He was a hearty man with a winning style and warm smile.

He was beloved by his employees, who called him “Big Foot” for his height and size: 6 foot, 4 inches tall and some 240 pounds.

But history will most likely recall the late Justin Herman, Arizona Highway Department director from 1956 to 1973, as the energetic leader who shepherded in the modern state freeway system, including the Black Canyon (Interstate 17), Superstition (US 60) and Maricopa (Interstate 10) freeways.

“During his tenure of office, some of the most important and mammoth advances and improvements in the history of Arizona road building, dating back to the date of Statehood in 1912, have been initiated and completed,” the Arizona Public Employee publication said of Herman in March 1970.

Here are some of those mammoth advances, according to our 2012 Arizona Transportation History report

"Work began on the Maricopa Freeway in 1958, and soon contracts for both new freeways were being issued on a regular basis. By 1961, more than six miles of the Black Canyon were open to traffic, from McDowell Road to Northern Avenue, and work was proceeding at a rapid pace. In late 1964, the combined Black Canyon–Maricopa freeway was dedicated from 16th Street to just north of the Carefree Highway. At a cost of $33.5 million for 30 miles of roadway – more than a $1 million per mile – it was by far the most expensive highway built in Arizona up to that time.”

You can see Herman, second from the left in the photo above, at that 1964 dedication of the combined Maricopa and Black Canyon highways.

Herman was the first and only director of the Highway Department, as before him the chief transportation official had been the state engineer. He served 17 years under five governors, being appointed three times to five-year terms before his retirement in 1973. By then, he had notched 42 years of public service, including 32 with the department.

The next year, 1974, the department he formerly headed became the Arizona Department of Transportation.

Larger than life character

Herman’s 93-year-old son – also named Justin Herman – described his dad in a recent interview as a larger-than-life character with contagious enthusiasm and a drive to get things done.

“He was an all-around great person, one of those people whom others liked immensely, a good-natured and highly intelligent man,” he recalled. “His big mission in life was to help people in any way he could.”

ADOT’s Spotlight bulletin echoed this sentiment in an article about Herman receiving a plaque for his service.

“Herman’s style of ‘personal diplomacy,’ marked by a friendly smile, a ready, powerful handshake, and a kind word to all, made him one of the most widely known state officials in Arizona,” it said.

To get a sense of how widely known Herman was, his son shared about the time he was renewing his license at the Arizona Department of Motor Vehicles, when the woman behind the counter recognized Herman’s name.

“I want to tell you a story,” she told him.

She was only a temporary employee at ADOT, she said, when her husband died of cancer. Around the same time, she was notified that her position would end and she would be let go after that Christmas. She told her supervisor how desperately she needed a job, and he urged her to see the director.

When she went to meet with Herman, he didn’t even know her name. He would meet with anyone regardless of position. She told him her situation, and the next day she was offered a job as a full-time employee.

“He was beloved,” his son said.

Just another cowboy

There was also the time when Herman met with the producer of a movie being shot in Sedona, who was requesting another road for equipment and vehicles.

That producer was John Wayne. And the road, which ADOT built, led to a cottage industry of westerns getting filmed in Sedona, his son said.

Justin Herman, center back, watches then-Gov. Jack Williams declare "Highway Week"

What did Herman think of John Wayne?

“He’s just another cowboy,” he told his son.

Another time in 1950, Herman, his wife and son were on a trip up north when the car broke down.  Herman had to wait hours for another car to come by and give him a lift to a telephone.

He telephoned his employees for help, since at the time he was Superintendent of the Shops. His colleagues were so amused by the irony that they put up a sign at the breakdown location called “Herman’s Crossing.” The site was even on the map for a while, the younger Herman said.

Years later, the younger Herman’s own son, Dan Herman, retrieved the sign – which had become riddled with bullet holes – and put it on his college dorm-room door.

Dan Herman has heard plenty of tales like these about his grandfather, but he was also was privy to his domestic side.

“He puttered in the yard, read Zane Grey novels and cooked sausage and eggs for us on Sundays,” he said.  

If this seems like a long time ago, it was. But the past came to the surface recently when Herman’s granddaughter, Luciana Herman, spotted a photo of him on ADOT’s Twitter feed. The photo at the top of this post, in fact. 

“Such a proud day for my grandfather back in 1964,” Luciana tweeted. “I-10 took up a lot of space in his head in those years as director.”

The second photo on the right shows Gov. Jack Williams signing a proclamation about "Highway Week" in Arizona. while looking on behind him, from left, are William Price, state highway engineer; Herman, and Lew Davis, chairman of the Arizona State Highway Commission. 

Perhaps Herman’s most lasting legacy will be his passion for his job and the people of the state.

His son said: “He just loved his job and the people so much!”