With its first monsoon season under its belt, the Arizona DOT (ADOT) says data shows that the agency's dust detection and warning system is working as designed.
Though ADOT says the latest monsoon season in Arizona was not the most robust weather event, there was one 20-minute event that provided measurable data. At one point during that storm, visibility dropped to less than 300 ft, triggering the speed limit to drop to 35 mph, which happens incrementally. 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,” Kevin Duby, statewide road weather manager, said in an ADOT blog post. “Our next step is to take the data we have to evaluate and determine the efficiencies of the system to improve performance.”
A study from 2010 and 2015 detailed how traffic was impacted by dust storms along this I-10 corridor, showing 83 dust-related crashes with more than half of them occurring within about a half-mile of each other. In 2016, ADOT and its partners began creating a system to help Arizona drivers be better equipped to deal with dust storms.
The dust-detection technology employed includes overhead message boards, variable speed limit signs, closed-circuit cameras, and short-range detectors for blowing dust, ADOT says. In addition, a long-range weather X-Band radar dish is part of the system, sitting atop a 22-ft-tall pole at the S.R. 87 interchange that can detect storms more than 40 miles away. X-Band is frequency range from 8 to 12 gigahertz. The lower frequencies make this band suitable for the harshest weather conditions, providing high link availability for weather-monitoring radar solutions.
SOURCE: Arizona DOT