Traffic and the Cities Proposed Solution
Poway is installing the Trafficware SynchroGreen adaptive traffic signal system (now part of Cubic Transportation Systems). According to the City, the first deployment is on the Espola Road corridor, with plans to expand to Poway Road and eventually other major arterial streets over the next several years. The system uses sensors placed upstream of intersections to continuously adjust green times based on actual traffic conditions rather than relying solely on preset timing plans.
This isn’t an experimental system. It has been deployed in hundreds of locations, including:
Palo Alto – Adaptive control along Sand Hill Road and a citywide Trafficware management system.
Livermore – Citywide advanced traffic management system.
Fresno – SynchroGreen has been used on Shaw Avenue and other corridors, with reported travel time improvements averaging about 27% on one major corridor.
Carlsbad – Uses Trafficware traffic management technology.
Santa Clara County – Trafficware management systems are in use.
Baytown – Adaptive control at 28 intersections on two major corridors.
Clark County – Adaptive timing adjusts automatically to changing traffic volumes.
Champaign – Evaluated by the Illinois DOT with measurable operational improvements.
What cities have reported
Agencies using SynchroGreen commonly report:
Reduced travel times during peak periods.
Fewer stops and less delay.
Better progression (“green waves”) along major corridors.
Automatic adjustment to seasonal changes, special events, and unexpected traffic fluctuations.
One thing to keep in mind
Adaptive systems often make side-street drivers wait longer than they are accustomed to during heavy traffic. That’s intentional: the software favors moving the greatest number of vehicles overall rather than minimizing the wait for any single approach. During Poway’s initial rollout, the City specifically warned that side-street delays of up to about 60 seconds could occur while the system learns and is tuned. I have found that turning left from Espola onto Del Poniente, the wait time has been as long as five minutes. Many neighbors have simply taken to running the light as their has been no traffic on Espola.
Cost
The cost depends on how much existing equipment a city can reuse.
Software and deployment: Approximately $13,500 per intersection.
Central server, training, and system setup: Approximately $20,000 for the entire system.
If intersections need new traffic signal controllers, cameras, radar, or communications upgrades, those costs are additional and can significantly increase the total project cost.
For a corridor with 10 intersections, a city might spend approximately:
Adaptive software: $135,000
Central software/server: $20,000
Plus any detector or controller upgrades.
Effectiveness
The results are generally positive, but they vary depending on the roadway.
South Carolina study (11 corridors)
One of the largest independent evaluations found:
Average 6.4% reduction in travel time
31.4% improvement in travel-time reliability (drivers experience more consistent trip times)
Greatest benefits occurred on corridors with 10 or more signals and average speeds below 35 mph.
Illinois (Champaign)
The Illinois Department of Transportation’s long-term evaluation found mixed results:
Initial improvements after installation.
After several years, only about 5% of performance measures improved, while many showed little change or even deterioration. Researchers concluded that adaptive systems require continuous monitoring and retuning—they are not a “set it and forget it” technology.
When it works best
Adaptive signal systems perform best when:
Traffic volumes change significantly throughout the day.
There are many closely spaced signals.
Congestion is moderate rather than severe.
The city has staff who regularly monitor and adjust the system.
Limitations
Adaptive systems are not a cure for congestion. They:
Cannot create additional roadway capacity.
Cannot eliminate delays if there are simply too many vehicles.
May increase wait times on side streets to keep the main corridor moving.
Require ongoing maintenance and engineering oversight to continue delivering benefits.
What this means for Poway
For corridors such as Espola Road and eventually Poway Road, Trafficare has the potential to:
Reduce stops and smooth traffic flow during rush hour.
Improve travel-time consistency.
Delay the need for some roadway widening projects by using existing pavement more efficiently.
Issues I see coming on Espola Road: During the times when the high school is going into session and after school let’s out, side roads such as Del Poniente and High Valley will see increased wait times
As a City Council candidate, I support the technology while also asking for measurable accountability, such as:
What was the total project cost ($500,000 budgeted)
What travel-time reduction is the City expecting?
How will success be measured (average travel time, number of stops, queue lengths)?
When will the City publish before-and-after performance data?
What are the annual maintenance and software support costs?