We’ve been following the US 89 Cameron roadway improvement project pretty closely here on the blog.

You might remember our last post described how crews were just beginning to remove the Cameron Truss Bridge, a 57-year-old structure that spans the Little Colorado River. Rather, we should say used to span the Little Colorado River because, as you can see from the newest project photos at right, the bridge is now gone.

Since this was a steel arch bridge, things went down a little differently than some of the other demolitions we’ve covered. Crews actually had to “cut” the bridge into pieces to disassemble it. Right now, those pieces are in the process of being hauled off site.

Just to give you an idea of how big a task this is, here’s an excerpt from Arizona’s Historic Bridge Inventory, explaining the bridge’s size (plus a revealing look at what things cost back in the 50s):

“In August 1957 Arizona Highway Department awarded a contract for the bridge's construction to the Vinson Construction Company of Phoenix. The contractors started work on the bridge that summer, completing it the following year for a cost of over $500,000. The Cameron Bridge was massive, consuming over 2,500 cubic yards of concrete and 1.2 million pounds of structural steel.”

Removing the bridge (and replacing it with two new bridges) is just part of the project...

Work started in March 2014 to expand US 89 from two lanes to four lanes through the community of Cameron between State Route 64 and the Little Colorado River (mileposts 464-467). Additional improvements include constructing a roundabout at the existing intersection of US 89 and SR 64, new sidewalks, streetlights and four pedestrian/livestock underpasses.

Crews have already completed the new northbound bridge and pedestrian walkway. The new bridge is being used by north- and southbound traffic.

Right now, northbound construction is pretty much complete including the curb, gutter, sidewalks and lighting along the northbound stretch.

Southbound roadway construction is underway and work on the southbound bridge is expected to start at the end of the month. Crews will begin by drilling foundations and working up from there.

We’ll continue to keep you updated on the progress! If you’d like more on the project, please revisit some of our previous posts.

We have some great news to share…

ADOT has been recognized for its environmental protection efforts while rebuilding the San Pedro Bridge through a sensitive conservation area on State Route 90 east of Sierra Vista! The American Road & Transportation Builders Association Transportation Development Foundation’s annual Globe Awards this month highlighted ADOT’s work to protect the natural environment during a nearly two-year reconstruction.

You remember this project, right? We blogged about it during construction and featured some videos that highlighted many of the project aspects that were recognized with the award.

The project, which was designed to replace a bridge originally built in 1955, included the construction of a new structure featuring wider traffic lanes, emergency shoulders and greater clearance over the San Pedro River.

The bridge’s location – it sits in one of two congressionally designated national riparian conservation areas in the country – factored into the project’s progression.

While the bridge replacement began in October 2012, work halted the following April through October to avoid disrupting the migratory bird season in the San Pedro Riparian National Conservation Area.

Other environmental mitigation measures included a containment plan to prevent debris from contaminating the San Pedro, along with lead paint abatement before the old bridge was demolished. Also, the project included re-seeding vegetation and planting trees. ADOT also employed a biologist to monitor construction impacts on the river as well as the more than 200 animal species and 250 migratory bird species in the area.

The San Pedro Bridge is an important link between the communities of Sierra Vista, Tombstone and Bisbee. The $6.2 million project was completed in March 2014.

More on the award
The Globe Award recognizes transportation agencies that do an outstanding job protecting the environment in the planning, design and construction of infrastructure projects. The recognition was in the category of bridges costing less than $10 million.

If you’ve driven recently on the Loop 202 Red Mountain Freeway, you might recognize the structure pictured to the right.

It sits near the Val Vista Drive exit, spanning westbound travel lanes, and while it’s not something you might see on every work site, it serves an important function on this project.

Referred to as a Bailey Bridge, which according to the Federal Highway Administration, is a temporary, prefabricated steel bridge that’s easy to transport, the structure shown above utilizes a conveyer belt to transport freshly mixed concrete from the batch plant just off the freeway to the median where crews are working to add an HOV lane.

It’s sort of brilliant because using the conveyor belt to move concrete over the freeway to the work zone saves countless truck trips. If the structure wasn’t there, trucks would have to be loaded up with concrete at the batch plant, get onto the freeway, and cross over several lanes to the work zone in the median.

Now, trucks can be staged within the work area without having to impact traffic – the concrete comes to them!

Transportation Defined is a series of explanatory blog posts designed to define the things you see on your everyday commute. Let us know if there's something you'd like to see explained ... leave a comment here on the blog or over on our Facebook page!

The Cameron Truss Bridge, a 57-year-old structure that spans the Little Colorado River, is coming down soon…

The bridge removal is part of the US 89 Cameron roadway improvement project that we’ve been telling you about since last summer.

Construction started in March 2014 to widen US 89 from two lanes to four lanes through the community of Cameron within the Navajo Nation, approximately 50 miles north of Flagstaff.

Once complete, the work will result in a new four-lane divided highway (two lanes in each direction) through the community.

Removing the existing Cameron Truss Bridge and replacing it with two new bridges at that location is a major part of the project. Improvements also include constructing a roundabout at the existing intersection of US 89 and SR 64, new sidewalks, streetlights and four pedestrian/livestock underpasses through the 3.5-mile project.

Right now, crews are beginning the bridge removal, as you can see in the photos above.

They’ve already constructed the new northbound bridge, which is what both north- and southbound traffic is using now (the northbound bridge also has a pedestrian walkway). Once the old bridge is completely removed, crews will start working on building the new southbound bridge.

Project Supervisor Rick Schilke explains that removal of the old bridge will take about a month…

“We’re taking down a steel arch bridge … you don’t see a whole lot of those anymore,” said Schilke, adding that crews are beginning to remove the bridge deck. From there, they’ll cut the steel bridge into six pieces, each of which will be disassembled and hauled off site.

Motorists are reminded to drive with caution through the work zone and are advised to be alert for construction equipment and personnel when driving through this project site.

Find additional details on the project page.

About a month ago, we shared a quick update on the I-15 Virgin River Bridge No. 6 rehabilitation project – you might remember seeing photos of the bridge deck demolition and rockfall containment work.

Today, we’ve got even more project details for you in the video above…

ADOT Resident Engineer Adam Carreon explains that up until now, most of the work has been below the deck (and drivers), but that has changed.

“The substructure is complete, all the columns and piers are built, the abutments are built, but a lot of the work now is transitioning to the top side of the bridge, where the public will have a view of everything going on and really see a big change with the replacement of the deck,” he says in the video.

What drivers need to know
Earlier this week, crews began work to install the girders on the new northbound bridge structure. The work will continue through the end of March and will require intermittent traffic breaks. Drivers traveling on I-15 between Mesquite, Nevada and St. George, Utah, should plan ahead for construction delays.

Drivers will also want to prepare for potential delays next weekend (March 6-8) due to a NASCAR racing event at the Las Vegas Motor Speedway. While no active construction will take place during the weekend, ADOT anticipates an increase in traffic as motorists make their way through the existing work zone that’s nearly 100 miles northeast of Las Vegas.

What’s ahead
The $27 million bridge rehabilitation project began in March 2014 and is anticipated to be complete in 2016. Work includes the replacement of the bridge’s superstructure (girders, deck and railings), as well as widening the roadway through the narrow passage of the Virgin River Gorge.

“Over the next six months, we’re going to build the northbound section of the bridge,” says Carreon in the video above. “Once that happens, we’ll switch traffic onto the new bridge and start the same process over again on the southbound side.”

Learn more by checking out our previous posts.

It’s been a while since we checked in on the Virgin River Bridge No. 6 rehabilitation project that’s happening up in the far northwestern corner of the state, but as you can see crews have kept busy…

In the slideshow above, you’ll notice a few falling rocks, but don’t worry – that was all planned! In addition to the ongoing construction, crews worked recently to clear rocks within the work zone. The rockfall containment required some traffic breaks through last week.

You’ll also see some photos of the bridge deck demo.

If it looks a little different from other demolitions we’ve featured in the past, that’s because this bridge sits over the Virgin River and many precautions are being taken to protect the area below. We have video with many more details coming your way soon. Until then, check out our previous posts and project photos. 

What drivers should know
The $27 million rehabilitation of Virgin River Bridge No. 6 began in March 2014, and is anticipated to be completed in 2016. This significant project includes the replacement of the bridge’s superstructure (girders, deck and railings), as well as widening the roadway through the narrow passage of the gorge.

Drivers should allow for up to 15 minutes extra travel time during construction, weekdays from 6 a.m. to 6 p.m. Additional delay time may occur on weekends due to heavier traffic volume and special events. The busiest travel times through the Gorge are Friday through Sundays. With limited alternate routes due to the remote location of the I-15 Virgin River Gorge corridor, ADOT urges drivers to plan ahead and allow extra travel time.

Work is continuing on the US 89 Cameron roadway improvement project, up in northern Arizona.

In fact, as you can see from the photos above, crews are really making a lot of progress on the job. Before we tell you what’s been happening on the project, let us first give you some background…

This project kicked off in March and is designed to expand US 89 from two lanes to four lanes through the community of Cameron within the Navajo Nation, about 50 miles north of Flagstaff.

Major work includes the widening of US 89 to two lanes in each direction between State Route 64 and the Little Colorado River (mileposts 464-467) and the removal and replacement of the existing Cameron Truss Bridge with two new bridges (one going north and one headed south) at that location. Additional improvements include constructing a roundabout at the existing intersection of US 89 and SR 64, new sidewalks, streetlights and four pedestrian/livestock underpasses.

Currently, crews are working to open the new roundabout by the end of this year.

The new bridge is also progressing. Crews are getting ready to pour the deck over the next month. Once that is complete and cured (a two-month process), work on the barrier, joints, surface grooving, lighting, fencing, guard rail, paving and striping will take place into late March/early April.

If you live or drive in the area, you’ll be interested to know that the new lights will be turned on soon for the east half of the project (you might also have noticed that artwork on the pedestrian underpasses!).

More details

The project is scheduled to be complete by fall 2016. Drivers can expect at least one travel lane to remain open during construction. This project is being constructed in two phases. During the second phase of construction all traffic will be moved onto the newly constructed roadway, which is anticipated to be completed summer 2015.

Earlier this month, when we gave you a quick update on the Virgin River Bridge No. 6 rehabilitation project, we promised a video to showcase all the progress being made...

Today, as you can see above, we’re keeping our word!

Driving through during construction

If you’ve driven on I-15 through the project area, tucked away in the far northwestern corner of the state, you know it is a busy corridor, something that ADOT takes into careful consideration when working a project like this.

“We can’t just tear the bridge down and expect interstate traffic to take local roads,” says ADOT Senior Resident Engineer Steve Monroe in the video. “If you take out any part of that section of Interstate 15, it’s a really long way around.”

Monroe continues by explaining what crews are working on at the moment…

“Right now, they’re working on putting in the support columns,” he says. “Once they have that done, both north- and southbound will be sharing one half of the bridge – one lane in each direction. Then the half that’s open will get removed. Then they’ll replace that with a wider section that goes onto the new support columns that we just built. Then, we’ll put traffic all on the new side of the bridge and go demo out the old half of the bridge.”

More about the project

Work on this extensive rehabilitation project started in March and is expected to take up to two years to complete. Located about 20 miles south of St. George, Utah, the $27 million project includes the replacement of the bridge’s superstructure (girders, deck and railings), as well as widening the roadway through the narrow passage of the scenic Virgin River Gorge.

One more thing…

When you watch the video, you might notice that Resident Engineer Adam Carreon says, “Bridge 6 is functionally obsolete and structurally deficient and needs to be replaced to adequately handle current and future traffic loads.”

Don’t let those terms take you aback. As we explain in this blog post, these classifications do not mean that a bridge is unsafe. Structurally deficient can mean that a component of the bridge needs rehabilitation. Functionally obsolete is a term often used when a bridge has sub-standard geometric features, such as narrow lanes or shoulders or inadequate clearance.

You can also revisit some of our previous posts and check out our I-15 photos on Flickr.