With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a series called, “From the Rearview Mirror.”

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Have you all been good this year? Santa is watching even when he’s busy delivering toys to members of the Havasupai Tribe with some help from the U.S. Marines. This video, originally posted Dec. 12, 2012, is one of our favorites. It shows how ADOT’s Grand Canyon Airport played a role in helping Santa deliver toys and food to the bottom of the Grand Canyon.

Grand Canyon Airport helps Marines deliver toys to Havasupai

By Ryan Harding
ADOT Office of Public Information

A different sight greeted the staff at the Grand Canyon National Park Airport on Dec. 3 when instead of tourist helicopters, two U.S. Marine Corps CH-46E Sea Knight helicopters landed to engage in their annual mission to deliver toys and food to members of the Havasupai Tribe who live at the bottom of the canyon.

This event, known as Operation Supai, has been conducted every year by Marine Medium Helicopter Squadron 764 (HMM-764) based out of Edwards Air Force Base in California.

The Grand Canyon airport, owned and operated by the Arizona Department of Transportation, provides support to this Marine squadron every year by providing jet fuel, a temporary base of operations and local ground transportation before and during the mission. In past years when snowy conditions threatened the success of the operation, ADOT staff would plow the landing pads and runway so the squadron could still deliver goods to the tribe.

“The support ADOT provides is invaluable,” said Major Charles Nunally, executive officer and helicopter pilot for the squadron. “Without the support of the airport, we wouldn’t be able to do this mission.”

HMM-764 partners with the local Marine Toys for Tots program based in Flagstaff and St. Mary’s Food Bank every year to bring 150 bags of toys to over 100 children and 100 boxes of food and turkeys to the small, remote tribe. Their CH-46 helicopters allow them to deliver the goods down into the Grand Canyon where the Havasupai live. The Grand Canyon airport serves as a staging area to load goods and personnel and refuel the helicopters.

“This is the biggest day of the year for the tribe,” said Rick Wiselus, a Toys for Tots volunteer and board member on the Marine Corps League Charities. “The smiles on the kids’ faces are heartwarming. The airport is wonderful to us every year. They pull together to help us.”

Operation Supai began in 1995 when the Northern Arizona Marine Corps League requested a squadron to deliver goods to the Havasupai. HMM-764 was selected for the mission, and they have delivered goods every year for 17 years to the tribe which consists of around 300 people.

The Havasupai Reservation is remotely located near the southwest corner of the Grand Canyon National Park outside of the main park area. They are largely dependent on tourism as their primary source of revenue. This annual Marine operation is something the Havasupai have come to depend on every year.

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a series called, “From the Rearview Mirror.”

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Originally published on Oct. 21, 2011, this blog post highlights something that most people don’t get to see every day – a bridge’s substructure. In the post and accompanying video, you’ll learn all about caissons and how they give bridges strength. The video also gives a close-up look at how caissons are built and put into place – an interesting process to see.

Bridges are a favorite topic here on the ADOT Blog and in the years since this post was first published, we’ve continued to blog about the structures. If you’d like to learn more, revisit some of our previous bridge blog posts after you’re done learning about caissons.

Building a Freeway: Massive underground caissons give bridges strength

You know when you drive under or over a freeway bridge that it’s a massive structure...

There are the two abutments (the upright supporting structures at each end that carries the load of the bridge span), there are usually center columns or piers, and, of course, the girders and the bridge deck (the part you actually drive across).

The girders and the deck make up the bridge’s superstructure. (You can tell how much goes into a bridge’s superstructure by checking out what goes into taking one down.)

But what you don’t see is that buried beneath the bridge is part of the equally impressive substructure formed by rows of caissons – massive steel-and-concrete pillars that support and lock in place the abutments.

The substructure, which is made up of the caissons and the abutments, ensures that the bridge is secure and strong enough to support not only its own weight, but also the weight of all the vehicles that drive across it every day.

The caissons are formed by tying thousands of feet of rebar into massive steel cages that are then lifted with a crane, lowered into drilled shafts, and filled with concrete. Several feet of rebar is left rising out of the ground, which is what the abutments are ultimately secured to.

There’s no such thing as a “standard size” caisson…their lengths and diameters vary from project to project and bridge to bridge based on several factors, including the soil type and the expected and actual weights the bridge must support.

Generally speaking, caissons for most bridges in Arizona are between 40 and 120 feet deep and 5 to 12 feet in diameter.

There’s also no set number for how many caissons each abutment will require – that, too, varies by bridge.

Take the three bridges being constructed for the new phase of Loop 303 in Surprise, for example. The bridge abutments at Waddell and Cactus roads are supported by 23 caissons each (46 total per bridge), while the bridge at Greenway Road, which is only partially elevated over Loop 303, requires just 20 total caissons (10 under each abutment).

The video above shows the fabrication and installation of those Loop 303 caissons. The steel cages for these particular caissons are 95-feet long and weigh about 20,000 pounds. The cages were lowered into 88-feet-deep drilled shafts and filled with 80 cubic yards (eight truckloads) of concrete each.

If you’re keeping tally … that’s eight truckloads for each caisson, times 106 caissons, for a total of 848 cement truckloads (for just those three bridges)…and that is just part of the substructure!

The concrete for these caissons cures in about 24 hours, clearing the way for the next phase of building a freeway.

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a series called, “From the Rearview Mirror.”

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Originally published one year ago, this blog post highlights a very big milestone: the completion of all four ramps connecting Loop 303 and I-10. The post and the video mark the conclusion of a project that started back in 2011. That new interchange was – and still is – important, not just for West Valley drivers, but to the entire state because of its ability to help to expand commerce while also easing travel throughout the region.

We’ve blogged a lot about the Loop 303 and we’re not done yet. In the coming weeks, we’ll be sharing some updates on the continued improvements to the freeway. Several projects, stretching from I-10 to Happy Valley Parkway, are designed to improve traffic conditions.

All ramps are open at the Loop 303/Interstate 10 traffic interchange

Have you heard the news? All four of the ramps connecting Loop 303 and I-10 are open!

We told you about the first two ramps (southbound Loop 303 to eastbound I-10 and eastbound I-10 to northbound Loop 303) last month. Shortly after that, the two additional ramps (westbound I-10 to northbound Loop 303 and southbound Loop 303 to westbound I-10) opened up to drivers on Aug. 24.

As you can see in the video above, there’s also a frontage road system connecting Sarival Avenue to Citrus Road – it is expected to open by mid-September and is the last piece of this phase of the interchange project. Phase II of the project, which will provide southbound access from I-10 to Van Buren Street, is currently in design and is expected to begin construction in 2016.

Looking back

Work on the interchange started in late 2011 and we’ve been covering the project’s progress along the way. We thought it might be fun to look back at some of those posts and videos. After you finish watching the video above, check out these links to learn more about:

• When the Loop 303/I-10 project began
• Progress on the interchange
• A big milestone
• The project’s almost finished
• The ribbon cutting ceremony

Of course, the interchange is just one part of the improvements happening along the Loop 303 corridor. ADOT is working to improve Loop 303 to create a six-lane freeway with three general-purpose lanes in each direction between I-17 in Phoenix and I-10 in Goodyear.

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a new series called, “From the Rearview Mirror.”

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Originally published on Aug. 22, 2013, this blog post gives a behind-the-scenes look at the ADOT Sign Shop, a place where thousands of signs are created each year. We followed this post up with a look at how ADOT created signs back in 1979 (surprisingly many of the methods employed then are still being used today!).

A look at ADOT's Sign Shop

Behind the scenes at ADOT's Sign Shop.

The ADOT Sign Shop is one very busy place…

Nearly 35,000 signs were created there during last fiscal year alone – that averages out to almost 3,000 signs each month!

Work orders come in from all over the state and can range from one or two signs to enough to re-sign a whole route (as was the case after a landslide forced a closure on US 89 – multiple new signs were needed to make drivers aware of the detour routes).

In addition to all the signs you see as you’re driving the state’s highway system, the sign shop crew also is responsible for creating the signs posted in ADOT rest areas and MVD offices.

Every sign is created by following guidelines (relating to size, color, shape, etc.) established in the federal Manual on Uniform Traffic Control Devices and ADOT’s Manual of Approved Signs.

Sign Shop Supervisor Marvin Phillips says his busy crew is dedicated. “Our customers are the driving public,” he said. “Their safety is our No. 1 concern.”

Check out the slideshow above for a behind the scenes look into ADOT’s Sign Shop.

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a new series called, “From the Rearview Mirror.”

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Originally published on Aug. 29, 2011, the video featured in this post gives a dizzying look at a girder installation (we’ve blogged about girders a couple of times since then).

This post also refers to the reconstruction of the Mescal/J-Six Bridge, which you might remember was completed in September 2011.

Tiny camera captures bird’s eye view of girder installation

If you’ve been following along in the blog, you know that we’ve been chronicling ADOT’s reconstruction of the Mescal/J-Six bridge in southern Arizona since it was severely damaged when two semi trucks collided underneath it back in March. Completion of the fast-tracked bridge reconstruction is slated for later this month.

Here's a shot of the GoPro in action. The inset photo gives you an idea of how small the camera really is.

Last week, crews installed 35,000-50,000 pound girders and our video team wanted to explore a creative way to take you behind the scenes of what goes into placing a 25-ton piece of concrete.

To get the perfect shot, they looked to a GoPro® Hero. GoPros are tiny (1.6” x 2.4” x 1.2”, 3.3 oz) HD cameras that let photographers get some incredible shots they never would have been able to otherwise.

Conditions weren’t exactly ideal (check out our Facebook page for pictures of the tarantula and other creepy crawlers that joined their shoot and the extreme weather that loomed in the distance), but they couldn’t miss a chance to secure a GoPro to one of those massive girders! (You might want to sit down before watching this one…it may make you a little dizzy.)

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a new series called, “From the Rearview Mirror.”

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We like dirt, here on the ADOT Blog and we’ve written a lot about it over the years. From testing it, to moving it and everything in between, dirt has been an outstanding topic. Originally published on March 16, 2012, this post talks about why ADOT sometimes “paints” dirt green…

This dirt isn't green for St. Patrick's Day, but there is a good reason for its hue!

Green dirt has nothing to do with St. Patrick's Day

We won’t blame you if you see this green slope at the Loop 303 and US 60 (Grand Avenue) and think it's part of a St. Patrick’s Day stunt, but we promise this is no gimmick!

The mound of dirt is green for good reason, albeit one that has nothing to do with the holiday…

ADOT crews just seeded it with a wonderful mix of desert flowers and groundcover plant material.

The seed mixture is actually sprayed on and has an all-natural green dye in it. This dye helps whoever is doing the spraying make sure they get full coverage. In time, the dye will fade, so the slope won’t be green forever!

If we get some nice spring rains, we should see things blooming and growing on the slope in about 45 days.

About now, you might be wondering what this dirt mound is doing ... just sitting there. Maybe you're also asking why ADOT goes to the trouble of seeding slopes like this one.

Well, as part of the Loop 303 Improvement Project, crews had to excavate and haul about 150,000 cubic yards of dirt away from the roadway alignment south of US 60 so bridges could be built at Waddell and Cactus roads.

They hauled the dirt to this location just for the time being.

In the future when it comes time to build the interim traffic interchange at US 60 and Loop 303, this dirt will be used during construction.

But by seeding it now ADOT is able to control dust. The vegetation that grows will cover the soil and prevent dust (landform graphics work in a similar manner). Seeding also helps prevent erosion.

So, even though there’s no St. Patrick’s Day connection, we’ll take this chance to wish you a little luck of the Irish anyway!

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a new series called, “From the Rearview Mirror.

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Do you remember what you were doing three years ago today? We sure do! Our team was prepping for Arizona’s big birthday on Feb. 14, 2012. Arizona was turning 100 and our plan was to document everything that ADOT does in a 24-hour span.

On the big day, we kept readers updated by sharing our photos through social media and on the ADOT Blog. The post below came along a month later and features video that was captured on the state’s Centennial. Now, as the state is almost set to turn 103, we want to say: Happy Birthday, Arizona!

Centennial video captures a day in ADOT history

When Arizona turned 100 last month, we celebrated by documenting everything ADOT does across the state in a single day.

And, oh what a day it was!

Our team was up early – out on the road, covering everything from construction projects and maintenance work to planning meetings and the MVD.

If you followed along with us back on Feb. 14, you saw our photos, kept up through social media and probably recall that we promised a mini-documentary detailing the day.

Well, that video is ready and we’re very proud to announce its premiere!

The video speaks for itself … so, we won’t say much more, except that we hope you’ll sit back, relax and enjoy what our team has put together!

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a new series called, “From the Rearview Mirror.”

Originally published on Aug.18, 2011, this post explains how crews regularly clean and maintain the I-10 Deck Park Tunnel.

Cleaning, maintenance all part of I-10 tunnel upkeep

Originally published in 2011, this video shows how the Deck Park tunnel is maintained.

With roughly 240,000 vehicles driving through it each day, the I-10 Deck Park Tunnel needs the night off every once in a while for a good, thorough scrub!

Just about every four months, the tunnel is closed to traffic in order to allow crews the chance to wash the walls, maintain the ventilation systems and check on the tunnel’s 3,700 light fixtures (about 150-200 light bulbs are changed out each quarter!).

Crews typically complete the cleaning over two nights. That means only one side of the tunnel needs to be closed each night … leaving the other direction open to traffic.

Cleaning the white tile walls not only gives the tunnel a fresh look, but it also helps brighten things up a bit.

“We’re washing the walls and keeping them clean so the light bounces off the wall onto the deck so it makes a better drive through,” says ADOT Highway Operations Supervisor Ed Walsh in the video above.

A little history…
For anyone fairly new to the Valley, it might be hard to believe that the Deck Park Tunnel represents part of Interstate-10’s “final mile.”

It was 21 years ago this month that the tunnel was completed, closing up the last remaining gap in the 2,460-mile-long interstate that stretches across the country.

The project was a big one because the path of this final mile was in between two historic Phoenix neighborhoods.

Designers came up with an innovative plan to limit the impacts on the communities. Builders dug out the freeway’s path, put in the 10-lane roadway and covered up the top of the road with a deck made out of 19 side-by-side bridges, created a tunnel and then built a 30-acre city park on top. The project took more than five years to finish and cost an estimated $700 million.

With hundreds of blog posts in our archives, we understand if you haven’t had a chance to read them all.

However, there’s a lot of interesting content in those early posts and we don’t want you to miss out. That’s why we’re looking back and highlighting some of our favorites in a new series called, “From the Rearview Mirror.”

Originally published on Oct. 6, 2011, this post explains how ADOT creates the landform graphics you see near freeways and the practical purpose these features serve…

Landform Graphics help with dust, erosion (and they look nice too)

As ADOT employees, we naturally get a lot of transportation-related questions thrown our way by friends and family... it’s just something that comes with the job!

Crews work on the large landform graphics along I-17.

By far, one of the most frequently asked questions has to do with HOV lanes and why ADOT builds them after the freeway is constructed (we answer that one in this blog, by the way).

But, another question we regularly get focuses on the rock landscaping surrounding our Valley freeways.

People want to know why we don’t just use trees and shrubs instead of rock. Others wonder why we landscape the area at all. Well, here’s the answer...

The main purpose of all freeway landscaping is really a practical one it helps control erosion and dust.

According to ADOT’s Chief Landscape Architect LeRoy Brady, anything that breaks up the rainfall (such as rock landscaping) or has a root system and holds soil together is going to help handle erosion.

As for dust control, Brady says rock landscaping and other types of plant-based landscaping help simply by covering the dirt.

“Because you don’t have bare soil, you don’t have the dust. It eliminates the dust source,” he said.

The type of rock that’s used matters, too.

Brady says his department sponsored a study that researched what size and grade of rock would work best for controlling erosion. The study was completed about 23 years ago, but the information is still used today.

Not only does landscaping help with erosion and dust, it has the added benefit of improving the aesthetics along freeways!

Rock landscaping is less expensive to maintain than planting and trimming trees and shrubbery... and rocks don't exactly require a lot of water.

ADOT works with the local communities to determine how to enhance the scenery along the freeways. Take for example the landscaping project along the recently upgraded I-17 in the north Valley.

ADOT worked with the city of Phoenix to create the landscaping theme and settle on designs, which are created to reflect Arizona's heritage and environment.

Brady says "context-sensitive design" is an effort in transportation to design and construct environmentally sound projects that fit and relate to the community, “instead of something that’s foreign and has no relationship.”

Along I-17, great care was taken to create designs that really fit the community.

About 15 colorful landform graphics made of crushed granite have been created for the project. There are a few Gila Monsters that have now taken shape at the Carefree Highway interchange and along the slopes at the Jomax Road interchange there’s a design patterned after a Hohokam water bowl.

It’s a challenging prospect to take a landscaping pattern from paper to the extra-large canvas of a freeway slope.

The process starts with site visits. Crews use flexible PVC piping and rope to set patterns before using spray paint to outline the design on the ground. Metal edging is then used to create the borders for the different sections of the colored rock and then the rocks are put in place.

Landform graphics and rock landscaping aren’t the only affordable and sustainable options for our freeways.

The location of the freeway often plays a role in determining what type of landscape to go with, as it did on a recently completed stretch of Loop 303.

There’s a lot more to freeway landscape design that we’ll cover in future blog posts. In the meantime, check out ADOT’s Roadside Development Web page.