Over the summer, the Arizona Department of Transportation (ADOT) installed an adaptive signal timing system on State Route 77, which is the primary north-south route connecting Tucson and Oro Valley and serves approximately 60,000 vehicles daily.
The technology adjusts the timing of traffic signals based on the number of vehicles on the road and their speed. It can modify the length of signal cycles, including left turn arrows.
“Sensors on the corridor provide information about the speed and volume of traffic on the road,” James Gomes, ADOT traffic engineer in Tucson, said. “The software uses that data to send information to each traffic signal along the route and adjust the signal timing to accommodate the traffic demand we’re experiencing at the time.”
So far, approximately two minutes have been taken off the morning southbound commute on Tangerine and Rudasill Roads south of Orange Grove Road, a 10 percent reduction. The more than 8.5 miles route used to take 20 minutes.
The northbound commute has been reduced by three minutes in the morning and one minute during the afternoon.
ADOT engineers have discovered that since the technology was installed, fewer drivers are speeding.
The system is the second installed in Arizona.