Drivers waiting for the on ramp signal to turn green in order to get onto the freeway, may discover their wait time might take a little longer.
Officials with the Arizona Department of Transporation will begin testing changes in the timing of the signals along the northbound State Route 51 beginning Monday. The testing is expected to cause longer red lights for the signal as ADOT takes a look at how the signal adjustments affect freeway traffic.
According to a press release, ADOT said the process is expected to take a couple of days as the changes are expected to be in place for at least three weeks as part of the initial phase of tests.
As part of the project, the red lights on the northbound 51 may hold vehicles for several more seconds, but detectors along the entrance ramps also will assess if ramp traffic is backing up. According to ADOT, the system is designed to adjust the red and green light timing to limit the amount of traffic waiting to enter the freeway.
ADOT said that another system study of the ramp-meter programming along the 51 freeway is planned for the near future. The study will look at how individual meters can be used to respond to traffic conditions several miles away and adjust the signal timing to help improve traffic flow along a longer stretch.
The ramp meter project is one of ADOT’s key performance indicators under Governor Doug Ducey’s call for continuous improvement among state agencies: decreasing the percentage of time freeways in the Phoenix metro area are congested.
The meters have been in place for many years along many of the Valley’s freeway on-ramps to enhance traffic flow as well as safety by creating gaps between vehicles entering freeways.
Currently, the meters are programmed with predetermined red-light intervals based on historical traffic data.
ADOT added that it is currently working with the city of Phoenix on the ramp meter project and will also monitor any impacts to traffic on local streets intersecting with the 51 freeway.