ADOT’s high-tech dust detection system is poised and ready for action when the first monsoons of 2021 roll into the Valley.

The first-of-its kind system was fine-tuned and activated in time for the official June 15 start of the 2020 monsoon season.

Only, except for a few cameo appearances, the star of that show failed to appear. By meteorological standards, monsoon season 2020 was pretty much a dud.

“It was a ‘nonsoon’,” said Larry Hopper, a meteorologist with the National Weather Service. “It was the hottest and driest monsoon on record.”

Will monsoon season 2021 be any wetter? Maybe, maybe not, according to recent climate reports. Chances are equal for a similar, slightly wetter or slighty drier season than last year.

But hold onto your hats and remember your safe driving rules. Forecasts call for a "greater potential" for dust storms, blowing dust and wildfires in 2021, especially in the earlier part of the monsoon season.

ADOT expects the dust detection system installed along 10 miles of Interstate 10 to be in high gear this season.

May 2020 to April 2021 saw the driest 12 months since 1895. Last year's no-show brought little to saturate the ground. This leaves an above normal amount of dry earth that, if the wind blows sufficiently, become dust storms.

Kevin Duby, ADOT’s statewide road weather manager, said the system was deployed successfully during a few storms last year, but he is eager to put it to the test during what is anticipated to be a dustier season.

“It worked well,” Duby said. “The variable speed limits signs worked as intended and did reduce speeds.”  

The speed limits are only one part of the system, which stretches between Eloy and Picacho Peak, from mileposts 209 to 219. Severe storms can create hazardous driving conditions across the Valley, but this stretch gets more than its share.

The most dangerous aspect of monsoon storms is the lack of visibility that thick walls of dust create. It can be extremely difficult to see during a big dust storm, which is one reason ADOT has longed urged motorists to “Pull Aside, Stay Alive” during a monsoon storm.

On this 10-mile stretch, 13 visibility sensors use light beams to determine dust particle density, and once they hit certain levels, the system activates overhead message boards and variable speed limit signs.

Programmable speed limit signs every 1,000 feet can change the legal speed limit from 75 mph to 35 mph.

A weather tower – that's the big ball pictured on the right – can detect storms more than 40 miles away and send the data to ADOT and the National Weather Service.

Duby said ADOT is looking forward to receiving information from the system to help make roadways safer.

“We feel confident the system is working as intended and hopeful we’ll see more data coming in and see how the motoring public responds to conditions.”

Read how the system tracked the "nonsoon" season and some of the top awards it earned in the "Dust detection and warning system tracks its first season" article.

With its first monsoon season under its belt, data shows that ADOT’s innovative dust detection and warning system works as designed.

Monsoon 2020, however, was not the most robust weather event, jokingly dubbed a ‘nonsoon.’

“It was a mixed blessing,” said David Locher, resident engineer for the project. “Less dust storms is obviously a good thing when it comes to driving conditions; however, we didn't have the normal weather events that would have been ideal for data gathering in our first season.”

There was one 20-minute event that provided measurable data. At one point during that storm, visibility dropped to less than 300 feet, triggering the speed limit to drop to 35 mph, which happens incrementally. How did drivers react to the warning system? The loop detectors showed that the average vehicle was driving about 45 mph, a big drop from the normal 75 mph limit.

“We do know that the system is working — it is doing what it’s supposed to,” said Kevin Duby, statewide road weather manager. “Our next step is to take the data we have to evaluate and determine the efficiencies of the system to improve performance.”

Often debilitating, dust storms in the area between Tucson and Phoenix have been a safety concern for several years. A study from 2010 and 2015 detailed how traffic was impacted along that Interstate 10 corridor, showing 83 dust-related crashes with more than half of them occurring within about a half-mile of each other.

The 10-mile area between mileposts 209 and 219 was identified as the focus of safety efforts. In 2016, ADOT, Arizona Department of Public Safety and National Weather Service staff, as well as vendors and contractors, began creating a system to help Arizona drivers be better equipped to deal with dust storms. Nothing of this nature existed so it was a momentous undertaking and would require substantial funding. A Federal Highway Administration grant was secured to help fund the $72 million project, which also included widening I-10 and improvements to the State Route 87 traffic interchange.

The dust-detection technology employed includes overhead message boards, variable speed limit signs, closed-circuit cameras and short-range detectors for blowing dust. In addition, a long-range weather X-Band radar dish is part of the system, sitting atop a 22-foot-tall pole at the SR 87 interchange that can detect storms more than 40 miles away. X-Band is frequency range from 8 to 12 gigahertz, which is most often used for civil, military and government radar applications such as weather monitoring, air traffic control, maritime vessel traffic control, defense tracking and vehicle speed detection for law enforcement. Its lower frequencies make this band suitable for the harshest weather conditions, providing exceptionally high link availability for weather-monitoring radar solutions.

Despite the literally dry run this year, the first-of-its-kind dust-detection and warning system has already received some impressive kudos. It received regional recognition in the 2020 America’s Transportation Awards contest in the Operational Excellence category. Sponsored by the American Association of State Highway and Transportation Officials, the U.S. Chamber of Commerce and AAA. The National Weather Service (NWS) also named ADOT as a 2020 Weather Ready Nation Ambassador of Excellence, for upholding the shared mission of protecting life and property through proactive public outreach and hazard mitigation efforts, and specificially cited the dust detection system.

This perfect storm of technology was assembled for this project, and its impact will be measured more in depth as time goes on.

We all know what to expect when the monsoon whips up dust storms that race across the desert between Tucson and Phoenix: strong winds, limited visibility and hazardous driving conditions.

But drivers on that stretch of Interstate 10 should expect something very different this summer when storms hit: reduced speed limits, speed feedback signs and new overhead boards that display urgent safety messages.

These features are now working together as part of ADOT’s dust detection and warning system, which became operational just in time for the 2020 monsoon season that officially began June 15. This video shows you how this first-of-its-kind system works on a 10-mile segment of I-10 between Eloy and Picacho Peak, along with what drivers will see when dust storms automatically activate the system.

This system was developed by ADOT to improve safety during dust storms. But it only works if drivers heed the warnings. So make sure to pay extra attention to the safety messages on overhead signs and to obey the reduced speed limits, which are enforceable. Speed limits can drop to as low as 35 miles per hour, depending on real-time conditions in the area.

You can read more about the dust detection and warning system on our website.

Please remember that this technology is no substitute for common sense. Wherever you are traveling, be sure you've reviewed our dust storm safety tips at PullAsideStayAlive.org. 

Let’s face it. We all use “to do” lists to identify the items we want to accomplish every day. Whether it is a “to do” list at work or an infamous “honey-do list” at home, these lists help us stay focused and identify the tasks that are needed to get the job done. When we can put a check mark next to an item on the list to note it is done, what a great sense of accomplishment we feel.

I get the same feeling in describing the accomplishments completed by the employees at the Arizona Department of Transportation this past fiscal year. We have had a very productive year in serving our customers, the people of Arizona, in providing a safe and efficient transportation system. We have strived to make sure you get home to your loved ones safely. It’s our True North – Safely Home. Our employees are dedicated on all fronts to get everyone Safely Home. We have tried to spark conversations with friends and family on the importance of being a safe driver. We have made vast improvements to streamline our processes so you spend less time at our Motor Vehicle Division offices. We complete highway construction and pavement preservation projects on time. And we get law enforcement officers faster information to help stop wrong-way drivers.

 Let me share just a few items on our ADOT “to do” list and highlight the accomplishments so far:

• Constructed a new traffic interchange at Interstate 10/Ina Road in the Marana/Tucson area that is separating vehicular traffic from railroad activity and widening lanes for better mobility and safety.
• Continued to make significant progress in the construction of the largest public-private partnership program, Loop 202 South Mountain Freeway, with the anticipated limited opening the freeway at the end of the year.
• Launched a new safety website, FocusOnDriving.com, which provides helpful tips and resources to make us all safer drivers.
• Implementing a dust detection system near Picacho Peak on Interstate 10.
• Modernizing our Motor Vehicle Division’s operating system to AZ MVD Now so we can serve our customers better and offer more services.
• Weathered a historic winter storm in February that brought snow to parts of the Valley.
• Continued to receive state and national recognition for our wrong-way driving detection system and sharing our findings with other DOTs to combat the problem.
• Found ways to eliminate waste in our processes – making change for the better. I am very proud of the effort our employees are demonstrating in embracing the principles behind the Arizona Management System.
• Recognized employees with Medals of Valor, Director Citation Awards and Director Pins for exemplary service to others and living our A.I.R. values (Accountability, Integrity and Respect).

Yes, our “to do” list at ADOT is vast and it seems never ending. However, we indeed have been able to put a check mark to items on our “to do” list. Even with a decrease in the number of employees at ADOT over the past several years, it is the dedication of the men and women who serve at ADOT for providing the sense of accomplishment I feel every day. Now, where did I put that “honey-do list?”

Over the decades, technology sure has changed but the weather-related issues facing Arizona drivers haven’t.

Back in 1973, the Arizona Highway Department launched a dust warning system that included 40 changeable message signs along 81 miles of Interstates 8 and 10 near Casa Grande. The signs were designed to display two different messages warning drivers of wind or dust. According to agency bulletins from that time, the messages were changed by DPS dispatchers in Phoenix using radio signals. Later, in 1976, ADOT modified the signs to refer motorists to specific AM radio stations for current advisories.

Today, we’re working on a dust detection and warning system on I-10 near the community of Picacho that will alert drivers to dangerous conditions. It is a little more advanced than what we had in the 1970s but the goal of our efforts remains the same – we want motorists to be aware of the situation ahead so they can make good decisions.

The new system will combine a number of technologies that you can read about on the project’s webpage. But no matter what type of warning system is in place, all drivers need to know that the most important thing they can do is to not drive into a dust storm. Visibility can very quickly drop to zero, putting everyone in a dangerous situation.

If you do encounter a dust storm and you don’t have time to exit the highway, remember these tips:

• Immediately check traffic around your vehicle (front, back and to the side) and begin slowing down.
• Do not wait until poor visibility makes it difficult to safely pull off the roadway – do it as soon as possible. Completely exit the highway if you can.
• Do not stop in a travel lane or in the emergency lane. Look for a safe place to pull completely off the paved portion of the roadway.
• Turn off all vehicle lights, including your emergency flashers. You do not want other vehicles approaching from behind to use your lights as a guide, possibly crashing into your parked vehicle.
• Set your emergency brake and take your foot off the brake.
• Stay in the vehicle with your seatbelts buckled and wait for the storm to pass.

Find more information online at pullasidestayalive.org and focusondriving.com/dust-storms.

By Tom Herrmann / ADOT Communications

For the past 16 months along I-10 near Eloy, construction teams from the Arizona Department of Transportation and our contractor, Coffman Specialties, have been doing what we’re trained to do: clear land, build new lanes and bridges, and recycle a 4-mile section of freeway to build the foundation for new freeway lanes.

Now, we’re about to start construction on something we’ve never done before – something no one has ever done before – in a spot in the desert where it can make the greatest impact on driver safety.

We’re beginning construction on a first-of-its-kind dust detection zone in the heart of Pinal County. The first work involves drilling and installing the foundations for new electronic message boards that will provide important safety information to drivers, followed by installing 10 miles of fiber-optic cable to connect the equipment that will make up the dust detection project.

As soon as we receive approval for a dedicated radio frequency for our long-range radar, we can schedule delivery and construction.

June is expected to see two important steps forward. First, eastbound traffic will be moved to new travel lanes that have been under construction since January. Later we’ll open a new eastbound on-ramp from State Route 87.

This summer we’ll add short-range radar to detect dust along the freeway, variable speed limit signs to slow drivers when the dust blows and cameras so our Traffic Operation Center in Phoenix can keep an eye on the area.

This pilot dust-detection zone will keep watch on an area north of Picacho Peak where we have experienced the most dust-related crashes.

We expect to have all of this in place by early fall. All in the name of driver safety.

A steady stream of traffic on the new WB lanes of I-10 at Picacho. The lanes opened about 3:30 a.m. EB traffic will move to the new lanes in about a month. pic.twitter.com/SaiiaADgPW

— Arizona DOT (@ArizonaDOT) December 6, 2018

By Tom Herrmann / ADOT Communications

Those driving west Thursday morning on Interstate 10, just after Picacho Peak, were the first to experience one of the most significant changes since I-10 arrived in central Arizona more than 50 years ago.

But chances are they were halfway through 4 miles of the newest freeway pavement in Arizona before realizing that anything had changed. The tweet above shows traffic flowing there.

Almost a year to the day since we began clearing and grubbing to make room for a new, wider stretch of I-10, with three lanes in each direction, we’ve opened the new westbound lanes from milepost 213 to milepost 209 near Eloy. Eastbound traffic will move to new pavement about a month from now, separated by concrete barrier while temporarily sharing what eventually will be pavement only for westbound traffic.

Drivers may not notice because there isn't as much as a turn onto the new pavement. In fact, we’ve removed a slight turn to the left for westbound drivers, creating a straight road up to State Route 87. The road will go under a new interchange with SR 87, then veer left to reconnect with the existing westbound lanes.

Once everyone is on the new pavement, we’ll demolish the current lanes of I-10 over that 4-mile segment and use the dirt and cement as a base for the new eastbound lanes. Eastbound drivers will get their own new lanes sometime this spring.

Then we’ll do something that hasn’t been done before: building an innovative system to identify dust storms and give drivers the information they need to make smart, safe decisions when blowing dust makes it hard to see where you’re driving.

Together, more travel lanes and dust detection will make I-10 safer, which is the reason we’re doing all of this in the first place.