Arizona DOT Updates Ramp Meters to Adapt to Traffic Conditions

Oct. 4, 2023
Upgrade allows nearby meters to talk to each other.

The Arizona Department of Transportation (ADOT) has upgraded about 75% of its 250 ramp meters across the Phoenix area to better adapt to real-time traffic conditions.

Ramp meters are timed lights along on-ramps that tell drivers to stop and alternate lanes as vehicles merge onto the freeway.

Now, Phoenix meters are getting enhanced computer programming to operate the timing of the meters’ lights based on traffic conditions. ADOT spokesman Doug Nintzel said the upgrade allows nearby meters to talk to each other.

“They’re speaking through computer data, but a ramp meter can now know what a neighboring meter’s area is experiencing with traffic a mile down the line," he said. "That ramp meter can then extend the time between cars entering the freeway, which helps with the overall traffic flow.”

ADOT plans to expand the use of adaptive ramp metering along additional sections of freeway across the state over time.