The Arizona Department of Transportation (ADOT) is continuing to upgrade freeway ramp meters to improve the flow of traffic, particularly during rush hour. The upgrades, recently completed along the 60 miles of Loop 101 in the Phoenix area, involve enhanced computer programming that adjusts the timing of the traffic lights in response to traffic conditions farther away from specific freeway locations. ADOT will continue to expand the use of these “adaptive ramp meters” to further freeway segments over time.
Arizona Department of Transportation Improves Freeway Ramp Metering
The Arizona Department of Transportation (ADOT) has been upgrading freeway ramp meters to enhance traffic flow, especially during peak hours. These improvements have been implemented across 60 miles of Loop 101 in the Phoenix area, stretching from near I-10 in the West Valley to Loop 202 in Chandler.
Interestingly, the upgrades don’t involve new ramp meter installations. Instead, ADOT has improved the timing operation of the alternating green and red traffic lights through advanced computer programming. This enables each ramp meter to react to traffic conditions beyond its immediate freeway location.
An adaptive ramp meter, for instance, is capable of adjusting to changes in traffic speed beyond its immediate on-ramp location. By analyzing traffic data about conditions a mile ahead, the meter can alter the timing of its green and red lights to promote better traffic flow. This process can be repeated along several freeway miles until traffic conditions improve.
It’s worth noting that the adaptive ramp meters have also been programmed to operate outside traditional weekday rush hours. This helps manage traffic flow during sporting events, concerts, and weekend construction closures.
ADOT officials have promised to expand the use of adaptive ramp metering to more freeway sections over time, enhancing traffic flow in the state.