Struts, blueprints and girders filled her daydreams ... and Afrin Hossain has turned them into reality as one of ADOT's newest bridge designers!

Born in Bangladesh, Hossain's interest in bridge design came early, thanks to her father who served as a civil engineer in the country's roadway department.

"Seeing my father work," Hossaid said, "seeing the blueprints he brought home, and seeing his shoe filled with asphalt after a busy construction day is what inspired me to get my undergraduate degree in structural engineering at Bangladesh University of Engineering and Technology." While there, Hossain studied structures like the Golden Gate Bridge in San Francisco. "The more I got to know about these structures the more I fascinated I became with them," she said.

Another influence and inspiration was fellow countryman and high-rise-design innovator Fazlur Rahman Khan.  Khan pioneered many improvements in skyscraper and high-rise design. He designed the former Sears Tower in Chicago. He was also an early trailblazer in computer-aided design, as well. "As a Bangladeshi, I also wanted to design and build just like him," Hossain said.

Hossain eventually earned a doctorate while in Canada in structural engineering and presented her work and research in many countries. The travel gave Hossain opportunities to see structures such as the Eiffel Tower in France and the Astoria-Megler Bridge in Oregon. It was the U.S. highways and bridges, however, that inspired her the most. 

"Living in the States for approximately three years, helped me gain a new appreciation for roadway infrastructures," she said. "Here, in the U.S., roadways, bridges (George Washington, Benjamin Franklin, Golden Gate, other bridges in Portland, and Pittsburgh etc.), tunnels (Holland, Lincoln, Chesapeake Beach etc.), retaining walls, noise bearing walls, ramps, interchanges, nested exits - all just amazed me."

Hossain decided to settle in Arizona, and began teaching other eager students at Northern Arizona University about engineering and working with materials like steel, concrete and timber. Her enthusiasm and teaching experience helped Hossain land a job at ADOT ‒ despite the pandemic and other challenges.

What's next? Hossain says she's looking forward to designing smart hybrid bridges incorporating concrete, steel and timber. "Whenever, I drive on Arizona roadways, I always pay a close attention to infrastructure details," she says.

"I am passionate about designing irrespective of the kind of the structure: building, bridges, roadways, foundations, etc. I envision myself not only just designing but also seeing my design be built."

In another chapter of “while you were sleeping,” we tell the story of the overnight work that recently went into creating the concrete deck for the northbound side of the Interstate 17 bridge that’s under construction above Central Avenue in Phoenix.

For ADOT, the I-17 bridge over Central Avenue had reached the end of its service life. Makes sense, since it originally opened to traffic back in 1962.  Over the past year the old bridge has been demolished in phases and a new bridge has taken shape south of the downtown area.

One of the last major moves was the concrete pour for the new northbound bridge deck. It takes a number of loads of concrete shipped via trucks. And as you can see in this ADOT I-17/Central Ave Bridge Video, an extended boom pump system delivered the concrete from street level on Central Avenue up to the bridge deck. It reminds me of a series of fire hoses that pump concrete instead of water.

Crew members then poured the concrete into the network of steel rebar that provides strength for the bridge deck. Specialized equipment, including a Bidwell pavement roller, is then used to spread and smooth the concrete pavement that drivers will be traveling on within a matter of months.

For this particular operation, 545 cubic yards of concrete were poured for this span in just a matter of hours.

So let’s review the project’s advances since work started in May 2020. Project phases included demolishing and reconstructing the southbound side of the steel-girder bridge. I-17 traffic, which had temporarily been sharing the old northbound side of the bridge, was then shifted to the new southbound span earlier this year. In turn, that allowed the same type of demolition and reconstruction work to take place for the new northbound side of the bridge.

Now it’s on to the last stages of work to finish the entire bridge so I-17 traffic can once again travel through the area with three lanes in each direction. The new structure will be wider to accommodate regional plans for additional lanes along I-17 when future funding is available. Increased clearance below along Central Avenue will provide more room for commercial trucks as well as Valley Metro’s future South Central Avenue light-rail line.

The $13.5 million project has been funded in part by Proposition 400, a dedicated sales tax approved by Maricopa County voters in 2004.

American engineer and educator James Kip Finch said “The engineer has been, and is, a maker of history.”

That can definitely be said of the engineers and team members working on the Pinto Creek Bridge project as they are creating a replacement for a 72-year-old bridge, located on US 60 about six miles west of Miami, to keep a southern Arizona community moving.

When the project began in 2012, many factors came into play, including addressing historic preservation with the Federal Highway Administration and bridge aesthetics with the U.S. Forest Service. Another consideration was environmental impact, which led to the mitigation and conservation of the Arizona Hedgehog Cactus in the canyon.

An interesting development was the discovery of a mine adit, which is basically a prospector’s tunnel, a consideration during the original construction in the 1940s. The team did 3D modeling of the foundation excavation limits to determine the type of foundation that would reduce any risk due to the mine adit.

ADOT used value engineering to develop improvements to the construction feasibility review and efficiency of the bridge, saving about $1.5 million.

“Adjustments were made to the foundations and column reinforcing for efficiency and constructibility,” Bridge Designer Rafe Davis explained. “A bid alternate was developed in the plans and specifications which provided the contractor flexibility.”

The bridge is now about 73% complete. The girder lift took place in April, but it was an involved process

“The girders took more than three months to fabricate, not including the time for required submittals and to prepare the structural steel shop drawings,” Project Supervisor Kim Vanvolkinburg said. “Once girder delivery to the project began, it took them about six weeks to set and splice all the girders and cross frames. The contractor brought in multiple cranes, and had to move them several times due to the logistics of working adjacent to the existing highway and within the canyon below.”

The projected completion date is January 2022.

“This will likely adjust some as there is a lot of work yet to be completed,” Vanvolkinburg said. “Hopefully, the weather will cooperate.”

Read more about the bridge project and progress in the ADOT Blog. Discover photos of the project and the girder lift on Flickr. 

On State Route 73 in the Fort Apache Reservation, alongside the North Fork White River in some of the prettiest country around, ADOT is in the process of replacing an old bridge deck. 

By the standards of the region, the Post Office Canyon Bridge, built in 1968, isn't quite a senior citizen at 53 years. But if it could talk, it would tell you the top song that year was "Hey Jude," by The Beatles, minimum wage was $1.60 an hour and a Big Mac was 49 cents.  

The single span, steel girder bridge rises more than a mile above Post Office Canyon at 5,912 feet. 

It is located nearly half-way down an 11-mile stretch of SR 73, between Indian Pine near State Route 260 and the Alchesay National Fish Hatchery, that was designated in 1993 as the White River Scenic Road. The route is a U-shaped loop, about 40 miles long with one end on US 60 north of Carrizo and the other near Indian Pine and State Route 260.

According to the state-published Arizona Memory Project, SR 73 started out as little more than a foot trail: 

“With the establishment of a military camp in 1870 that would be renamed Fort Apache in 1879, the development of rough trails into passable packed-earth roads became necessary. In 1929, the old trail that would become SR 73 allowed horse-riding soldiers and mule-drawn freight wagons to reach the remote garrison from both the north and the south.“ 

The Post Office Canyon Bridge was probably named after the canyon it crosses, the Post Office Canyon, said the ADOT engineer who is overseeing the deck replacement, Navaphan Viboolmate (Noon) of ADOT’s Bridge Design Section. 

Before 1968, an earlier bridge across the canyon had a deck built from timber, Viboolmate said. It was torn down to make way for the current bridge.

“It was an open design,” he said. “Driving on it you could see side rails and cross rails.” 

Located in Navajo County between mileposts 348 and 349, the bridge sits on a section of SR 73 that is classified as a Rural Major Collector Road. 

“It connects to local communities, including Fort Apache, Whiteriver and Cedar Creek,” Viboolmate said. “It connects State Route 260 and US 60.” 

By ADOT engineering measurements, the bridge is safe, but because ADOT specifications and standards have evolved, it’s time to replace the current deck with reinforced concrete 8-inches thick and to replace deck drains, deck joints and bridge barrier transitions, among a host of other improvements. The project will reconstruct and significantly extend the life of the bridge

The project is in full swing and crews are demolishing and replacing the old decks.

According to the project website, the following restrictions are in place from 6 a.m to 6 p.m. seven days a week through September:

• SR 73 is narrowed to one lane of alternating north- and southbound travel near the Post Office Canyon Bridge (mileposts 348-349).
• A temporary traffic signal helps drivers travel through the construction area.
• 12-foot vehicle width restriction in the work zone.
• Reduced speed limit in the work zone.

When you cross the newly refurbished span, you now know you will be one mile high, on the White River Scenic Road and a Rural Major Collector Road --  and on a passage whose history began in the 1800s.  

When it comes to hiring promising young engineers for the Arizona Department of Transportation, there’s probably no bigger cheerleader than Candee Samora.

After all, Samora, ADOT’s Engineer-in-Training and Intern Program manager, has landed her dream job and brings her considerable enthusiasm to work every day.

“I’ve wanted to work for state government since I was 12 years old,” she said. “And I wouldn’t want to be anywhere else but ADOT.”

She gets to work with young engineers in training, who also bring considerable enthusiasm to their roles.

“They bring excitement, new blood, new ideas,” Samora said. “They are fabulous.”

In interviews, engineers-in-training (EIT) extolled the virtues of a program that provides so much education and training in so many areas and allows them to see the role of engineering in major projects from start to finish.

“Working with projects so large-scale and critical for the traveling public has been very interesting to see and be a part of every step of the way,” said Brandy Wagoner, recently assigned to Deer Valley Construction.

In the video above, we interviewed Jimmy Naujokaitis, an ADOT resident engineer in Phoenix, who is an enthusiastic graduate of the EIT program. 

"Being in the EIT program allows you to get integrated into ADOT culture and see how things are run," he said. 

Like a lot of future engineers, when he was a kid he excelled in math, science and Legos! 

ADOT can choose from a wide pool of applicants since the agency no longer requires a Fundamentals of Engineering certificate for eligibility.

Recently, the criterion shifted and trainees are required to pass the exam during the 2-year-program, Samora said.

ADOT also sets the trainees on the path for passing their Professional Engineer license, which is considered the highest standard of competence. 

They receive an apprentice-style education that provides hands-on experience and side-by-side mentoring in such disciplines as roadway design, environmental planning, multimodal planning and materials lab. Every few months, they rotate between Roadway Design, Project Management and outlying rural construction projects.

We recently asked a few engineers in training about what they like best about ADOT’s EIT program. Here are some of the highlights:

Wagoner, also quoted above, added that she likes seeing “first-hand how massive transportation projects travel from a vision, to a project, to each design team and how they work together to complete the design, to bid, and finally to construction.”

And the work environment is excellent.

“The atmosphere of being an ADOT EIT is so welcoming, encouraging and creates an environment that I have always felt comfortable and supported in,” Wagoner said.

Diana Palma, recently assigned to the Transportation Systems Management and Operations (TSMO) Division, enjoys learning first-hand about each unit’s responsibilities and the potential for career progression within the state. 

She also listed “the opportunity to apply principles of the Arizona Management System to everyday activities and to see the positive impact on practices.”

Babak Dehghani called the program “an amazing introduction into the professional world.”

He enjoys seeing how ADOT brings construction projects from beginning to finish and how, by working under registered professionals, he has gained the training and experience to become registered as a professional engineer.

Steven Neher, recently assigned to the Multimodal Planning Division, listed the opportunity to work with many different groups, field visits, chances to grow and career development.

“All of these reasons culminate in this grand chance to better myself as a person, an engineer, and a professional, laying the foundation for techniques and habits that can help serve me to my benefit for years to come,” Neher said. “Every road starts somewhere and I'm glad mine began with ADOT.”

ADOT recently replaced the Rio de Flag bridge right in front of Flagstaff City Hall in just under a week. How were they able to tear down and remove an old bridge and install a new one so quickly?

By using an accelerated bridge construction method where the parts of the new bridge are precast and then put in place like LEGO bricks. Now that Historic Route 66 has reopened to traffic, crews will continue working for the next several weeks to install the bridge barrier and sidewalks and replace the raised median and a portion of concrete pavement on Historic Route 66.

Our video team went up to Flagstaff and took some photos of the new bridge (above) as well as a time-lapse video of its installation (see below). After you check them out, plan a trip to drive over the new bridge yourself.

Rio de Flag Bridge Replacement Time Lapse from ADOT Vimeo-External on Vimeo.

Pop quiz: Can you name the longest historical bridge over Arizona's Gila River?

Give up?

It was the relatively unassuming Bylas Bridge on US Highway 70 in Graham County, near the community of the same name. It was 1,800 feet long and a culmination of many attempts to span the river.

The Gila River has been an issue for Arizona's bridge builders for a long time. It could go from a mere trickle to a huge flood – and back – in the same day. More money and time were spent building and maintaining bridges over this waterway than any other in Arizona. Among them were the Antelope Hill, McPhaul and the Gillespie bridges. Engineers were determined not to let the river's unpredictable nature hold them back.

The Bylas Bridge was designed in 1956 by the Arizona Highway Department. It consists of 23 equal-length spans, with the I-beam steel stringer superstructure carried by concrete abutments and bullnosed piers. Each span extended 80 feet, for a total length of 1,829 feet. The concrete substructure - the bit under the actual driving surface - rested on steel piles driven beneath the riverbed. The concrete deck was 35 feet wide and flanked on both sides by aluminum baluster guardrails with concrete bulkheads. Construction was completed in 1957.

After its completion, the Bylas Bridge carried mainline traffic on US 70 for decades essentially unchanged. In the 1980s, bank and pier-scour protection was done. In 2000 the bridge received minor repairs to the steelwork. 

Unfortunately, by the early 2010s it had become "functionally obsolete."  Simply put, the bridge was just too narrow and in no condition to support modern traffic needs. So in 2012, ADOT began a replacement project, which built a new bridge alongside the historical structure. The old bridge was then demolished in 2013. 

Though it's now long gone, and it didn't have the aesthetic touches of some other bridges, the original Bylas Bridge played an important role in getting traffic across the troublesome Gila River. Add in its trememdous length and you have a structure that's definitely worth remembering.