AMS-Safety

ADOT improving traffic flow on SR 95 in Lake Havasu with traffic signal coordination

ADOT improving traffic flow on SR 95 in Lake Havasu with traffic signal coordination

I-17 101 traffic interchange

ADOT improving traffic flow on SR 95 in Lake Havasu with traffic signal coordination

ADOT improving traffic flow on SR 95 in Lake Havasu with traffic signal coordination

May 18, 2021

PHOENIX –  Lake Havasu City residents and visitors will start experiencing a smoother flow of traffic on SR 95. Traffic signal crews with the Arizona Department of Transportation are installing updated traffic management technology on 20 signals along a 13-mile stretch of the highway 

In 2017, ADOT installed this technology along traffic signals in a 3-mile stretch of SR 69 in Prescott Valley and a 6-mile stretch of SR 69 in Prescott. The result has been an improvement in travel times by as much as 40%. It has also been implemented in Phoenix and Tucson. Using it, engineers monitor traffic conditions remotely, adjust signal timing, and diagnose and correct problems. The signals automatically adjust timing at certain times of the day based on anticipated traffic. 

Crews will be adding the remote technology from McCulloch Boulevard South to London Bridge Road. After installation, crews will monitor and make adjustments over the next month to optimize traffic flow at different times of the day.

The cost of the project is nearly $229,000.

These changes are being made through ADOT’s Transportation Systems Management & Operations Division. This division brings together traffic-engineering resources around the state to maximize resources, technology and expertise. This includes collaborating with other transportation and public safety agencies.

Shedding new light on your drive in the I-10 Deck Park Tunnel

Shedding new light on your drive in the I-10 Deck Park Tunnel

Shedding new light on your drive in the I-10 Deck Park Tunnel

Shedding new light on your drive in the I-10 Deck Park Tunnel

By Doug Nintzel / ADOT Communications
May 11, 2021

When it comes to driving through the Interstate 10 Deck Park Tunnel north of downtown Phoenix, it’s important that you’re not left in the dark.

It has taken a few visits to the idea factory to explore possible ADOT projects to upgrade, and actually replace, the original lighting system dating back to when the famous tunnel opened in 1990 as part of the “Final Mile” of I-10 constructed across the entire U.S.

Fortunately, the waiting has paid off with an innovative project being installed by ADOT crews that has now reached a milestone with work to add new LED lighting in the westbound side of the tunnel finished.

That means more than 1,500 of the LED lights are now lighting the way for westbound I-10 drivers using the tunnel. ADOT crews are slated to complete the eastbound installation this summer as more light fixtures are provided by a manufacturer.

While previous project ideas were considered more expensive, ADOT found a company that could provide LED lighting fixtures that work in the same locations as the original high pressure sodium lights. The result is a $1.4 million safety enhancement project that includes the “in-house” installation work by an ADOT team.

An initial review of the new westbound lighting is already showing a more than 60 percent reduction in energy consumption. We’re estimating annual energy savings of more than $175,000, which by my limited math skills would mean the project will pay for itself in less than 10 years.

The new LED lights in the Deck Park Tunnel are providing a noticeably improved, brighter and whiter level of light compared to the yellow tone of the old, outdated high pressure sodium lights. The new bulbs certainly will last longer, no doubt having a positive effect on maintenance work and costs. 

As with the old lighting system, the improved LED tunnel lights will be set at appropriate transitioning levels during daylight and nighttime hours to allow a driver’s vision to adapt given outside lighting levels. For example, the system will run fewer lights at night because of lower nighttime light levels outside the tunnel.

So ADOT has reached the halfway point with the I-10 tunnel lighting upgrades. We’ll keep you posted on when the next installation work on the eastbound side will require an overnight closure so crews can do even more work. As always, please focus on safe driving, especially as we head into the summer travel season.  

Work zone awareness is needed at all times

Work zone awareness is needed at all times

Work zone awareness is needed at all times

Work zone awareness is needed at all times

By Doug Nintzel / ADOT Communications
April 30, 2021

As transportation departments and other safety organizations across the country wrap up this year’s National Work Zone Awareness Week (NWZAW), we truly hope that the emphasis on this life-and-death issue stays with you at all times when you’re behind the wheel.

The national event, held April 26-30, provided ADOT with an opportunity to place a spotlight on dangers associated with traffic traveling through work zones – not just on our state highways but also local streets in communities across Arizona.

We want to thank media outlets who provided coverage of NWZAW, including live reports from an I-17 work zone where the freeway bridge over Central Avenue in Phoenix is being reconstructed. It was great to see TV traffic reporters here in the Valley taking part in “Wear Orange Day” on Wednesday as part of the week’s events.

Nearly a thousand fatalities occurred in 2019 in work zone-related crashes across the U.S., according to statistics provided by the Federal Highway Administration. The majority of those deaths involved drivers or passengers in vehicles.

Here in Arizona, law enforcement crash reports showed there were 15 work zone-related fatalities across the state in 2019. That number was 17 deaths in 2018. Last year ADOT lost one of its own, Frank Dorizio, who was struck and killed by a vehicle while he was setting up a sign along Interstate 10 in the Casa Grande area. 

These are the top reasons we ask you to take this issue to heart. You indeed could be a life saver by slowing down and staying alert when approaching any work zone.

If you were out on one of our Arizona freeways or highways during National Work Zone Awareness Week, you may have seen one of our safety messages, including “Give ‘Em A Brake, Stay Alert in Work Zones.” 

We’re looking out for the men and women who work dangerous jobs in order to make things better as we move about the Grand Canyon State. But we’re also looking out for you, and any passengers traveling with you. In turn, we depend on you to remember the importance of being careful well beyond this one week. 

Zipper merge eases traffic - and your dilemmas

Zipper merge eases traffic - and your dilemmas

Zipper merge eases traffic - and your dilemmas

Zipper merge eases traffic - and your dilemmas

By Laurie Merrill / ADOT Communications
March 31, 2021

Does merging on the highway pose a dilemma for you?

For a lot of us, a “Merge Left (or Right)” sign triggers an inner debate: Should we politely do what the sign says and merge now, or should we wait to merge later – and gain more ground – but feel guilty for cutting?

The zipper merge system ends the debate and encourages drivers to wait until the last minute to merge – without guilt!

What is the zipper merge, you ask, and what does it have to do with ADOT?

Glad you asked! No, it’s not a new line dance or a carnival ride, but a traffic system that organizes how motorists merge when a lane closes.

ADOT has been using the zipper merge on various projects since 2016. Currently, it is being used on the Meteor Crater and Two Guns bridge deck replacement and rehabilitation project on Interstate 40 east of Flagstaff.

Okay, but how does it work?

Here’s how, according to AAA. The zipper merge is like a zipper on a pair of jeans. Just as the teeth of your jean’s zipper come together, the zipper merge keep traffic coming together, smoothly closing the lane.

Motorists stay in their respective lanes until the final merge point, which is efficient because it’s not leaving one lane empty. It uses all available lane space.

At the merge point, vehicles take turns merging: The car in one lane merges, and then a car in the other lane merges, then the car in the next lane merges, and so on. Like a zipper!

Additionally, ADOT is testing a “smart work zone” in the westbound direction of the I-40 project. It uses a dynamic merge system with electronic signs and sensors and can be controlled remotely. When traffic is light, the signs ask motorists to merge well ahead of the closure. When traffic is heavier, the zipper merge system kicks in and signs ask drivers to merge later. You can read more about it here.

Dilemma resolved!

For more information about the zipper merge, check out this classic ADOT blog.

To see photos of the I-40 bridge deck and rehabilitation project, visit the ADOT Flickr album.

Lighting the way. ADOT converting I-10 Deck Park Tunnel’s lights to LED

Lighting the way. ADOT converting I-10 Deck Park Tunnel’s lights to LED

Lighting the way. ADOT converting I-10 Deck Park Tunnel’s lights to LED

Lighting the way. ADOT converting I-10 Deck Park Tunnel’s lights to LED

By Doug Nintzel / ADOT Communications
March 3, 2021

It’s definitely a case of “out with the old and in with the new” when it comes to the lighting system inside the Interstate 10 Deck Park Tunnel north of downtown Phoenix.

The Arizona Department of Transportation has been pursuing a project to replace the original tunnel lighting system for several years now. After all, the Deck Park Tunnel opened to traffic in August 1990 and the old style high-pressure sodium lighting system has been in use for all the 30-plus years since. An upgrade has been much needed.

Following consideration of various project ideas over time, enough funding was identified for a $1.4 million project that is now underway. New LED lighting fixtures are being installed, over the course of the next few months, to replace the old fixtures that held the sodium lights.

A test installation was done with a small section of lights last year and more of the new lights were put in during January above the westbound I-10 right lane within the tunnel. In fact, you might have noticed the “whiter” LED lights that are in versus the “yellow/amber” glow of the old lights.

The project team anticipates needing several Friday night closures of I-10, in either direction, over the next few months in order to change out the more than 3,200 fixtures that help light the way when you’re traveling through the tunnel.

The new LED lights are energy efficient and can be expected to last well over twice as long as their sodium predecessors. The anticipated annual energy savings are more than $175,000. Those savings will over time help pay for the cost of installing the new system.

So be prepared for ADOT to let you know which Friday nights will be used for closures so the lighting improvement work can advance this spring. Our Weekend Travel Advisory is a good thing to subscribe to via azdot.gov/Subscribe.

At age 30, the Deck Park Tunnel is getting a new look and you’ll notice a difference. As some experienced models might tell you – it’s all about the lighting.  

Measuring slopes to prevent landslides

Measuring slopes to prevent landslides

Measuring slopes to prevent landslides

Measuring slopes to prevent landslides

By Laurie Merrill / ADOT Communications
February 16, 2021

Arizona’s mountainous terrain is as beautiful to look at as it is to drive through, but keeping dirt from those slopes off roadways can pose a technical challenge.  

That’s one reason the Arizona Department of Transportation has deployed highly sophisticated measuring equipment on embankments across the state.

On a recent trip to State Route 87 between mileposts 224 and 225 south of Payson, ADOT Geologist James Lemmon and Engineer-in-Training Ivan Bystov inspected two examples of this technology. The hill they're working on is part of a decade-old landslide known as the Sunflower Landslide.  

Lemmon and Bystov hiked along a ridge on the east side of the highway toward what looked like a yellow chimney sticking out of the hillside. In fact, the yellow riser is a steel casing to protect the inclinometer pipe and the piezometer equipment inside the well.  

The inclinometer enables scientists like Lemmon and Bystrov to measure the rate of slope movement over time.

“We are trying to see if there is a change or any instability,” said Lemmon, an ADOT Geotechnical Design Section-Bridge Group member.

The information is used to take preventive action if the hill is moving down a slope toward the roadway.  

“We know we must do something to buttress it to keep it from moving,” Lemmon said.

Lemmon said there are about 130 individual inclinometer wells installed at 30 embankment sites around the state. Sunflower Landslide has over 20 active inclinometers that are read on a regular basis. Some are on the roadway surface, many are on the near slopes and several are near the very top of the steep road cutouts and mountain slopes.

The piezometer measures moisture and saturation levels.

"When designing and constructing bridge foundations, we need to know the depth of where the saturated water level is under the surface so construction equipment doesn't sink and disappear into the saturated earth, Lemmon said. "And we design the foundation for a saturated groundwater situation. Those depths to water are measured by the piezometers."

The piezometer Lemmon and Bystrov displayed goes down about 60 feet deep, but Lemmon said there locations on the Sunflower Landslide where they go down nearly 400 feet deep.

New AZ511 website feature improves trucking route information

New AZ511 website feature improves trucking route information

I-17 101 traffic interchange

New AZ511 website feature improves trucking route information

New AZ511 website feature improves trucking route information

February 9, 2021

PHOENIX – A new feature added to the Arizona Department of Transportation’s Traveler Information 511 website will help commercial vehicle drivers more easily plan their route through the state.  

This new feature at az511.gov allows truck drivers to see commercial vehicle restrictions along state highways. This way, they can plan their route to avoid those restrictions. Click on the ‘Map Legend’ box on the right-hand side of the screen and check the box next to ‘Truck Restrictions’ to bring up the truck restriction icons on the map. Clicking on an icon will show details including length and width restrictions and any escort requirements.

This is the latest ADOT innovation that helps professional truck drivers. Last summer, ADOT added a feature to the 511 website to show the total number of commercial vehicle parking spaces at each of ADOT’s rest areas so truckers can find a place to rest. 

Also last year, ADOT expanded the number of truck parking spaces along I-40 by nearly 100 spaces at the Haviland and Meteor Crater rest areas.

Nearly 2.4 million users have accessed az511.gov since the redesigned website launched in March 2019. More than 76,000 visited the site during the recent snowstorms at the end of January. For more information, please visit az511.gov and azdot.gov.

ADOT testing smart work zone along I-40 to make work zones safer for everyone

ADOT testing smart work zone along I-40 to make work zones safer for everyone

I-17 101 traffic interchange

ADOT testing smart work zone along I-40 to make work zones safer for everyone

ADOT testing smart work zone along I-40 to make work zones safer for everyone

February 4, 2021

PHOENIX – In order to increase safety and mobility in highway work zones, the Arizona Department of Transportation is studying a “smart work zone” at an existing I-40 bridge project located between Flagstaff and Winslow.

A smart work zone is a traffic management system that can be controlled remotely through computer networks, portable message boards and sensor technology to provide motorists with real-time traffic information as they approach construction work zones. This project utilizes a dynamic merge system, which is a specific type of smart work zone.

The dynamic merge system is designed to mitigate the potential hazards of lane closures by altering the time to merge based on the current level of traffic. When traffic is light, electronic signs placed well ahead of the work zone encourage drivers to merge into the open lane prior to the lane closure. When traffic is heavy, the system will encourage drivers to remain in the closed lane for as long as possible in what is known as a zipper merge.

ADOT has been utilizing the zipper merge on various projects since 2016. The zipper merge works by having drivers remain in their lanes and merge just before the lane closure begins. It’s a more efficient way of moving heavy traffic through a work zone where a lane is closed.

In order to study the potential impact a dynamic merge system can have on safety and mobility in a highway construction work zone, ADOT picked an existing bridge deck rehabilitation project on I-40 at the Two Guns and Meteor Crater bridges as a test site. 

ADOT set up a dynamic merge smart work zone in the westbound direction and a traditional work zone in the eastbound direction in order to compare the effectiveness of a dynamic merge system.

Drivers passing through the work zone toward Flagstaff from Winslow should follow instructions on when to merge through electronic message signs.

Crash data and speed data will be gathered from the smart work zone and traditional work zone and used to evaluate the impact and inform decisions on future highway projects.

ADOT used something similar during a recent project to rehabilitate three I-15 bridges in the Virgin River Gorge. The queue warning system, as it was called, included portable message boards informing drivers of stop-and-go traffic ahead. That system, like this one on I-40, used equipment that detected traffic in real-time in an effort to help reduce collisions and improve safety and mobility.

Riprap and hydro-seeded mulch help keep SR 87 safe

Riprap and hydro-seeded mulch help keep SR 87 safe

Riprap and hydro-seeded mulch help keep SR 87 safe

Riprap and hydro-seeded mulch help keep SR 87 safe

By Laurie Merrill / ADOT Communications
January 27, 2021

Motorists traveling to Payson from the Valley along State Route 87 may be familiar with the road and scenery, but are probably unaware of the feats of science and engineering designed to keep them safe as they pass along the way.

“On State Route 87 we rebuilt things so we don’t have steep grades and windy roads and much of it is safer,” said ADOT Geologist James Lemmon. “We don’t want streams flooding and rocks falling onto the road.”

One such project is the soil cement and hydro-seeded mulch mixture that covers grouted riprap along the banks of Slate Creek on SR 87 northbound, at milepost 227. This is about 7 miles before SR 87 intersects with State Route 188. 

The hydro-seeded mulch mixture was created by E. LeRoy Brady, manager/chief landscape architect for the ADOT Roadside Development Section-Roadway Engineering.

Here are some of the components: hydraulically applied compost containing, among other elements, seeds of about 30 plants chosen specifically to suit the environment. These plants include desert senna, incienso brittlebush, desert marigold, arroyo lupine and more.  

The hydro-seeded mulch mixture feels spongy and light to walk on, almost like paper-mache. It stretches along the sides of the highway and parallels the guardrails. It follows the creek bank and hugs the sides of the culvert that carries the creek under SR 87.

Under the surface, on the banks of Slate Creek, are large quantities of massive stones and soil, known as riprap. The riprap is secured with grouted cement, allowed to cure, and then covered with the hydro-seeded mulch. Together, this prevents the earth from eroding and washing the road away. It also keeps Slate Creek’s water where is should be – in the creek, according to Lemmon, who works as a member of ADOT's Geotechnical Design Section-Bridge Group.

We know that most drivers won't even think about these bits of engineering the next time they escape to the cooler weather of the high country, but that's okay. If it's doing its job, you don't have to.

2020 was the year of the bridge for northern Arizona

2020 was the year of the bridge for northern Arizona

I-17 101 traffic interchange

2020 was the year of the bridge for northern Arizona

2020 was the year of the bridge for northern Arizona

December 16, 2020

PHOENIX – While 2020 presented many challenges, the Arizona Department of Transportation continued to serve drivers in northern Arizona by using different methods, including the innovative bridge slide, to improve bridges to keep cross-country commerce flowing and increase the mobility of local traffic.

In Flagstaff, ADOT completed the replacement of the Fourth Street bridge over Interstate 40 on the east side of town in just six months using the innovative bridge slide method. The slide method allowed ADOT to construct the bridges to one side, then slide them into place over one long closure which greatly reduced the impact to the traveling public.

The new bridge improves safety, traffic flow and mobility in the area by increasing the number of lanes for vehicles to use and adding a protected path for bicycles and pedestrians on one side of the bridge. The protected path connects the Flagstaff Urban Trail System across the interstate.

Along Interstate 15 through the Virgin River Gorge, ADOT resurfaced the decks of Bridge No. 2 and Bridge No. 5, while Bridge No. 4 received a new deck. Work was completed this summer after important additional repairs were made. These improvements will ensure the continued life of these bridges to safely move cars and trucks cross-country.

For this project, ADOT used a first-of-its-kind queue warning system that included portable message boards informing drivers of stop-and-go traffic ahead. Using equipment that detects traffic in real-time, the system is designed to help reduce collisions as traffic builds.

ADOT also improved the Interstate 17 bridge over McConnell Drive as you come into Flagstaff. The project, which began in 2019, involved a full bridge deck replacement, bridge widening and sidewalk construction on the north side of McConnell Drive.

For more ways on how ADOT continues to serve drivers in northern Arizona, visit azdot.gov/projects and click on the North Central District.