Relief is on the way soon in the form of an InSync traffic optimization system now being installed on signals along Rosecrans, one of San Diego's busiest and most congested thoroughfares. A similar traffic- optimization system was installed six months ago on Torrey Pines Road on La Jolla Parkway in “the Throat” in between Interstate 5 and La Jolla Village.
“This is the same signal-optimization technique,” said Duncan Hughes, a city senior traffic engineer, who noted, “Rosecrans in Midway is among the heaviest-volume roads (in the city), not just Rosecrans, but all the crossing arterials.”
Seeking to combat worsening traffic congestion, city officials have created a $163 million master plan to install, over a 10-year period, modern stoplight timing systems and other advanced technologies that ease gridlock. The 10-year plan is intended to connect each of the city's 1,540 stoplights into a timing and coordination network controlled by a central hub.
Using technology to improve traffic flow is much less expensive than widening roads or building transit lines, city officials said.
Councilwoman Lorie Zapf of District 2, which includes the Peninsula, hailed signal optimization as a major step forward.
“This is great news for the residents and commuters of Point Loma,” said Zapf. “By optimizing signal timing, we can improve travel time and reduce greenhouse gas emissions moving the City forward with its Climate Action Plan. I am very supportive of this project.”
The InSync model being used for signal optimization in San Diego was developed by Rhythm Engineering in 2005. Instead of developing incremental improvements to existing traffic control tools and methods, the InSync system is set up to use computers to detect demand in real-time, then make immediate adjustments in signalization.
Nearly all traffic control systems today use digital hardware but remain constrained by analog thinking such as common cycle lengths, set sequences, fixed offsets and standardized allotment of green time, or splits.
The InSync Processor is instead a modern-state machine that can dynamically choose which phases to serve and instantly adjust and coordinate service and green time. By adapting to actual traffic demand, InSync is superior to predetermined signal-timing plans that, at best, estimate traffic demand based on a small historical sampling and generalize those results across years of traffic signalization.
InSync’s ability to constantly see and flexibly serve actual demand in the best way possible is what enables it to produce successful before-and-after results.
Traffic engineer Hughes noted new equipment is being mounted on Rosecrans traffic signals, adding the networked system of about a dozen lights on Rosecrans between Roseville and the Valley View Casino Center will be up and running likely in early 2017.
“Each one of those 12 intersections on Rosecrans are all networked together,” Hughes said, adding, “They talk to each other and share information. They'll make (computerized) decisions.”
What the city's hoping to achieve with traffic-signal optimization along Rosecrans, Hughes said, is to “decrease the number of stops. We'd like to see the travel time from end-to-end go down.”
Hughes added the Rosecrans Adaptive Traffic Control System is meant to “decrease gas consumption and decrease greenhouse gas emissions, all part of the city's Climate Action Plan.”
The Climate Action Plan aims to satisfy state mandates for reducing greenhouse gases, including a requirement to cut carbon emissions by 20 percent below 1990 levels by 2020, 40 percent by 2030 and 80 percent by 2050.