Drivers who have been impacted by the closure on US 89 might be happy to know that work is beginning on Navajo Route 20…

That means crews soon will start paving the mostly dirt road so it can (in a few months) serve as an interim detour route until repairs are finished on US 89.

Once complete, the N20 detour will reduce travel time for motorists heading to and from Page. And, yes, it will be able to accommodate the anticipated traffic volumes, including commercial truck traffic.

However, we’re not there yet, and we’re asking motorists to avoid using N20 until the upgrades are finished (likely by later this summer). Because, not only is it still a mostly dirt road, but very soon it will become an active work zone and delays are expected to take up to an hour

After the reconstruction of US89 is finished, N20 (which will be dubbed Temporary US 89, or US 89T, once it’s paved) will be relinquished to the Navajo Nation.

There is no timetable yet for reopening the portion of US 89 damaged by a February landslide, but we’ll definitely keep you posted. ADOT is committed to restoring this important travel route as soon as safely as possible. In the meantime, drivers can look forward to the shorter and more direct N20 detour.

Things have come a long way in the two months since a landslide buckled part of US 89 south of Page…

No, the route hasn’t been restored yet. But, as you can see in the video above, several steps already have been taken to return mobility to the area.

ADOT’s Senior Deputy State Engineer Rob Samour details a three-pronged approach that has been established as crews work toward an ultimate fix.

“We looked at the immediate, intermediate and ultimate solutions,” Samour says in the video. “The immediate solution actually took place within the first three weeks. We did start the geotechnical investigation and we were able to establish immediate access for emergency responders. The interim repair – the paving of N20 – is under the design phase right now. Hopefully we’ll be paving shortly. The ultimate repair of US 89 will eventually get a recommendation from our geotechnical engineers on a solution.”

So, while it’s still premature to lay out any sort of a timeline, drivers can know that ADOT is working toward identifying the long-term options and that we certainly recognize how important US 89 is to the community of Page and the region.

ADOT Director John Halikowski asks for patience and explains the process.

“The mountain has moved and literally to fix that roadway we are going to have to move that mountain in some way or we’re going to have to figure out a way to go around it,” Halikowski says in the video. “These are not quick and easy decisions to make because they do involve a great deal of technical issues in the engineering and geology areas but we are working on this as diligently as we can.”

When a landslide buckled a portion of US 89 back in February, the incident (unsurprisingly) brought many people together to work on restoring mobility to the area.

They’re still working. But today, rather than tell you about what they’re doing, we are going to focus on how they are staying organized.

Incident Command System

The incident command system, according to the Federal Highway Administration, “is a systematic tool for the command, control and coordination of an emergency response. ICS allows agencies to work together using common terminology and operating procedures for controlling personnel, facilities, equipment and communications at a single incident scene.”

ADOT is using the incident action planning process, which is a portion of the larger incident management process, to work through several objectives related to US 89, according to ADOT Emergency Manager Courtney Perrier Bear.

A few of those objectives are:

• Restore mobility to the area both short- and long-term
• Provide for the safety of site workers and visitors and security of the site
• Keep the public, stakeholders and the media informed of recovery activities.

An incident action plan not only outlines objectives, but it includes the tactics that will be required to manage whatever the incident is. An incident action plan can help everyone involved understand the situation and assists in determining things like meetings and work assignments.

Basically, an incident action plan helps get everyone on the same page…

“Safety of personnel and the public is the top reason for using the incident command system,” Bear says.

She explains that the system was born out of wildfires that broke out in the 1970s. Those fires spread over many jurisdictions, which meant many fire departments and organizations were involved. But because there wasn’t an effective, wide-ranging management system in place, disorder hindered efforts.

Frustrated, representatives from the fire agencies worked together in the aftermath to create a better emergency management system. From there, the Federal Emergency Management Agency (FEMA) adopted the Incident Command System and began teaching it.

Benefits of using the system

“It offers a better way to get a common operating picture,” Bear said.

She explains that ICS offers an efficient and faster way to restore services, secure life safety, conserve property and stabilize the incident.

ICS is about “getting everyone in the room and determining objectives,” according to Bear.

Good news for drivers who have seen their commute impacted by the US 89 landslide…

Last Friday (April 12), during its monthly meeting in Tucson, the State Transportation Board approved funding to pave Navajo Route 20.

You might remember that last month we told you about N20 – it’s the Navajo Nation tribal road that runs parallel to US 89. Once improved, N20 could establish a shorter route for the many drivers who regularly travel to Page and the Lake Powell area (see we told you it was good news for drivers!).

While the primary detour to and from Page and the Lake Powell area has been established by using US 160 and State Route 98, ADOT acknowledges the 115-mile-long detour, which is 45 miles longer than the direct route, can be a burden on drivers who have to use it every day. By paving N20, the detour route would be cut nearly in half and similar in length to the closed US 89 route.

The $28 million N20 paving project is scheduled to start next month — as long as all right-of-way and environmental agreements can be obtained through the Navajo Nation, Bureau of Indian Affairs and the Navajo Division of Transportation.

“After numerous face-to-face meetings, roundtable discussions and several presentations from Window Rock to Flagstaff, ADOT and its many partners, including Navajo Nation, Navajo Division of Transportation, Bureau of Indian Affairs and the Federal Highway Administration, have demonstrated great teamwork to put us in position to begin paving Navajo Route 20 next month if all agreements can get signed, sealed and delivered,” said Dallas Hammit, ADOT deputy state engineer of development. “ADOT is anxious to move forward to pave this road and create a more direct temporary detour route.”

The project would improve the existing 44-mile-long tribal route and upgrade so it could accommodate the anticipated traffic volumes, including commercial truck traffic. The major work is paving 27 miles of dirt road stretching from Bodaway-Gap to LeChee.

Construction could begin next month. ADOT’s goal would be to complete the work by early summer.

The project is eligible for reimbursement through the Federal Highway Administration’s emergency relief program, which provides funding to state and local agencies for the repair or reconstruction of highways, roads and bridges that are damaged in natural disasters and catastrophic failures. ADOT has already received $2 million in quick release funds to assess the damage and the stability of the mountain slope and conduct emergency operations.

The State Transportation Board designated N20 as Temporary US 89 (US 89T) during its special telephonic meeting on March 21. It had to be designated a state route before ADOT could spend any money improving the road. After the reconstruction of US 89 is complete, US 89T will be relinquished to the Navajo Nation.

There is no timetable for reopening the highway, but ADOT is committed to restoring this important travel route as soon as safely possible.

ADOT is currently conducting a geotechnical investigation, which is the first phase of the solution. Crews are monitoring the stability of the slope and the ultimate repair of US 89 will be based on the results of the geotechnical work.

We have heard from a lot of people who want to know when US 89 is going to reopen…

While we don’t have any sort of a timeline to give you yet, we can report that the geotechnical investigation is entering its final stages. Once complete, the information gathered will help engineers uncover the best long-term solution to restore the landslide damaged US 89 highway.

After receiving environmental clearance, heavy construction started Tuesday. Crews are working to cut a pathway down the slope to the base of the mountain slope.

That access path will allow the geotechnical engineers to dig pits, approximately 20-40 feet long and 10-15 feet deep, which will provide critical information regarding any movement that may be present at the base of the slide. The excavation work is necessary because it will lead to recommendations by the geotechnical team on what options are available within the site to realign the roadway or rebuild the existing roadway.

“This is the final piece of the puzzle we’ll need to wrap up this geotechnical investigation,” said Steve Boschen, ADOT deputy state engineer of design. “Prior to this, our drilling crews were only able to access this area via helicopters.

ADOT’s goal is to repair this critical section of highway and restore connectivity throughout the region as soon as possible. But before we can start the repairs, we need to determine the cause of the landslide and assess the safety of the slope.”

ADOT’s geotechnical investigation at the US 89 landslide site is the first phase of the solution. Crews are monitoring the stability of the slope and the ultimate repair of the highway will be based on the results of the geotechnical investigation. Efforts also continue on exploring the use of Navajo Route 20 as a temporary detour route while US 89 repairs are addressed.

You might remember that we blogged about inclinometers back in February – they’re the instruments used to measure slope inclination or movement at specific locations.

Well, today we have another technology that we want to tell you about called Time Domain Reflectometry.

Like inclinometers, TDR can help our geotechnical experts and geologists measure movement of a slope or a landslide. However, TDR technology looks and operates a little differently from inclinometers.

How does it work and what is it used for?

TDR technology consists of a coaxial cable (similar to the one that's coming out of your television set – but more heavy duty) that’s embedded or grouted within a vertically drilled hole (it might help if you can recall our milkshake straw analogy from the inclinometer post).

Alternately, a TDR cable can be attached to a grouted inclinometer casing (see photo above). That coaxial cable that's in the ground is then connected to a cable tester that sits outside the drilled hole.

You should know that the cable is installed in a precise way so that the zones of ground movement (shear planes) in the landslide mass are intersected.

Once the cable is in the ground, it will be able to detect ground movement that’s happening within the vicinity of the cable. If there is movement in the landslide mass, the cable becomes kinked, stretched or even sheared.

This damage creates a change in the impedance of the cable, which can be detected by the cable tester, says ADOT Engineering Geologist Nick Priznar.

“The cable tester sends an electronic voltage pulse that is reflected like radar from a damaged location in the coaxial cable,” he said. “The returned signal will show where changes have occurred along the length of the cable and can be compared to the signal obtained originally when the cable was undamaged. This makes it possible to determine the depth, progression and general magnitude of movement of the landslide zone that was intersected.”

TDR technology is often used in conjunction with inclinometers. That’s because the lifespan of the inclinometer casing is limited – slide plane movement can shear or distort the casing, eliminating its stable base or reducing its diameter to a point where the inclinometer probe cannot pass through the casing.

When, or if, that happens, the TDR system can be used to continue to monitor the movement/displacement. That’s because the TDR cable is usually more resilient to displacement than the inclinometer casing.

However the two systems are not equivalent, according to Priznar. While the inclinometer data provides actual measures of deflections the TDR cable tester can only provide depth and relative magnitude of displacement.

How are TDRs being used on US 89?

At this time ADOT engineers are in the process of developing the best strategy for implementing TDR technology for US 89.

In anticipation of utilizing this technology, TDR cables are being be secured along the outside diameter of select slope inclinometer guide casings (again, see photo above).

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!

Even though there’s a stretch of US 89 that’s not open, the businesses and communities surrounding the closure most definitely are.

That’s the message that area residents, business owners and ADOT are hoping to get out…

“With the busy tourism season coming up, there are a lot of people concerned in Page and the Lake Powell area with how this closure is going to impact their businesses,” says ADOT Public Information Officer Dustin Krugel in the video above. “That’s why we’re doing everything we can to let the public know that Page and the Lake Powell area are open.”

Motorists should know that they can still get to all the popular tourism destinations in the northern part of our state.

Traci Varner, general manager at the Lake Powell Days Inn, says the detour is actually really a pretty drive.

“It’s just a little out of the way, but it’s a beautiful ride,” she says.

It’s also important to note that US 89A is not affected by the closure. So if you’re heading to the Grand Canyon's north rim (when it opens up for the season in mid-May), Fredonia, Lees Ferry or Marble Canyon, the detour won't impact your drive.

So, to sum up … Page and the Lake Powell areas are open for business. And, judging from the video above, they’re all ready for the beautiful season ahead!