To lessen traffic congestion on La Jolla Parkway (hallelujah!), a program for “adaptive signal timing” is being rolled out, and is expected to be fully operational in the next few weeks.
Using cameras mounted on the mast arms over the intersections of La Jolla Parkway at Torrey Pines Road, La Jolla Parkway at La Jolla Shores Drive, and Torrey Pines Road at Ardath Lane, adaptive signal timing adjusts green light duration based on real-time increases and decreases in traffic.
In its pilot effort, the system showed an 18-24 percent decrease in delays, depending on the time of day.
“It’s an automatic system that will continuously monitor the traffic and change its (green light) time accordingly to improve the congestion on that corridor,” said Scott Robinson, Senior Public Information Officer for the City of San Diego. Noting that the summer tourist season is here, he added, “We know (La Jolla Parkway is) congested all the time so we wanted to go ahead and make this change. If it’s successful, it could be used in other areas in the future.”
La Jolla Parkway is the second major street to get this technology, but the first heavily trafficked arterial road. City Traffic Engineer Duncan Hughes explained the pilot program was on Lusk Boulevard in Mira Mesa, and the next streets to get the system are La Jolla Parkway, Mira Mesa Boulevard and Rosecrans Street.
“Those are three of the busiest corridors in the city, so now we’re going to see how it works on a highly congested corridor,” he said. “In the case of La Jolla Parkway, we’ve also always had seasonal traffic in the summer. We’re hoping to get some adaptability automatically without us having to go out there and constantly be making (light timing) changes.” During previous summers, the green light duration was manually adjusted by traffic engineers, and occasionally re-evaluated.
As Hughes explained, “This system is set up to try to get progression through the intersections as much as possible based on the traffic volume and vehicle counts that are detectable through the camera. But they also use that information to minimize side street delays. A traditional coordinated system will generally be on a fixed cycle for a couple of hours in the morning and then maybe a different cycle in the evening, or as we determine necessary. The idea of the adaptive system is we can automatically increase or decrease that cycle in response to real-time traffic conditions.”
The cameras were installed on the mast arms in late May, and then traffic engineers experimented with angles and pointing directions to get the best read of how many cars are in the area.
The next phase is to have the city get a baseline of wait times that the system can “optimize away from.” Once that baseline is established, the cameras will go live, ideally by June 11. The pricetag for equipment is just over $150,000 for all the cameras, with additional labor costs (from the installation) to be determined.
After about three months, the data will be reviewed to make sure the system is running smoothly. However, if a problem or area of improvement is detected before that, adjustments will be made at that time, Robinson said.
Hughes added, “It may take some fine tuning, so we are going to give it time to make sure it is performing as efficiently as it can. There are adjustments we could make … based on what we see and what we hear from the public.”
Those who would like to report a problem with the adaptive signal timing or any other traffic issue are encouraged to use the city’s new app, found from Google Play Store, the Apple Store and the city’s website. Robinson said, “We want to improve commutes, so if there are any issues, please report the problem.” The app can be found at sandiego.gov/get-it-done
But hoping for success, Hughes said, “This is a very congested corridor, as anyone that drives it knows, so there is no magic bullet, but we are hoping to see a change for the better.”