State transportation officials are increasing their use of remote technology to help keep traffic moving on portions of highways that pass through various communities across Arizona.
This technology has most recently come to the city of Maricopa.
With Maricopa’s population and traffic increasing, the Arizona Department of Transportation (ADOT) has installed a wireless communication system allowing technicians in Phoenix to monitor conditions on State Route 347 and adjust signal timing accordingly.
The number of complaints about traffic signals malfunctioning along SR 347 has also increased, at times causing excruciatingly long wait times for drivers.
“We’re working to make the best use of the existing road through Maricopa and improve traffic flow and safety,” ADOT Traffic Engineer Mark Poppe said. “While drivers will experience a better commute with this new system, our work is not done. The data will allow us to continuously measure performance and make adjustments that improve mobility.”
The TransSuite system, which is already used on more than 100 stoplights in Phoenix, is now installed on every traffic signal from I-10 and Queen Creek Road to Harrah’s Ak-Chin Casino. ADOT technicians put the system in over the summer and finished prep work this fall.
The system starts with a series of infrared and video cameras installed at each SR 347 intersection through Maricopa, allowing an ADOT technician in Phoenix to see exactly what is happening and modify the length of traffic signals to improve traffic flow.
Antennas, video cameras and heat detecting cameras allow ADOT traffic signal technicians to remotely monitor traffic and the traffic signals. Poppe said it will be an incremental and continuous improvement to area traffic and driving conditions.
Another part of the system automatically monitors travel times between intersections using Wi-Fi signals, such as those from smartphones. That anonymous information can alert ADOT technicians to delays.
The Wi-Fi signals are anonymously re-identified going from intersection to intersection, Poppe said, so that information can be used to tell ADOT what the travel times are.
“If a device has its Wi-Fi turned on, then we can pick that up all the way through the corridor, and that is a very good sample size of what the travel speeds are,” Poppe explained.
Poppe assured drivers that ADOT does not have access to any IP addresses and that all the information is anonymous.
“We only know it’s a Wi-Fi device, and nothing more, continuing down the path,” he said. “The information is sent to a company, Acyclica, and it sorts it all out and sends it back to us in the form of travel time information.”
Acyclica’s technology is used around the world to generate high-resolution traffic data at the intersection level. Its advanced analytics are used by cities and departments of transportation to manage traffic signals for both static-timing and adaptive systems.
“Historically all we’ve been able to do to monitor performance is to get in a car and drive it,” said Poppe. “That could take you almost all day to do what we can collect in just a few minutes with these Wi-Fi devices.”
Poppe said delays in Maricopa, like anywhere else in the state, are driven by the volume of traffic. Sometimes traffic is progressed more in one direction as well, he added.
For example, in Maricopa, ADOT would favor the northbound traffic along SR 347 in the morning and the southbound traffic in the afternoon and evening. He said ADOT also tries to limit the overall cycle length of lights to about two minutes as a general rule of thumb.
ADOT created the Transportation Systems Management and Operations Division, of which Poppe is a part, about a year ago to improve traffic conditions and overall transportation. Money from ADOT’s maintenance budget helped pay for the TransSuite system, according to Poppe.
Similar systems are used to remotely monitor traffic signals in Nogales, along State Route 77 in the Tucson area, and in the Phoenix area. One is also planned for Safford.
Over the coming months, researchers from the University of Arizona will evaluate how cost-effective the system has been.
UA researchers will compare and contrast, look at functionality and cost, and provide some guidance to ADOT as to what might be best route to go as ADOT implements these systems in other communities. Poppe said researchers are about halfway through right now, as they continue to go through lots of technical reviews, but should be finished by some time in 2017.