FOLSOM — Motorists in Folsom can expect to see new flashing yellow left-turn arrows coming to town in the near future, after the Folsom City Council approved a key purchase Tuesday night to move the pilot program forward.
On Sept. 9, the council authorized City Manager Bryan Whitemyer to execute a $160,906.25 agreement with Western Systems, Inc. for the equipment needed to implement the trial. Funding will come from the city’s Transportation Improvement Fund.
The approval covers the purchase of four new traffic signal controller cabinets and related components for intersections along Natoma Street at Prison Road, Wales Drive, Stafford Street and Coloma Street. The upgrades are required to accommodate the flashing yellow arrow technology, which was cleared for use nationwide by the Federal Highway Administration.
Flashing yellow arrows allow drivers to make a left turn after yielding to oncoming traffic, rather than waiting for a dedicated green arrow. The Public Works Department says this operational change will help improve traffic flow, reduce vehicle emissions, and enhance the driving experience. Currently, all of Folsom’s signals provide “protected only” left turns, except at Riley and Sutter streets in the Historic District.
The trial project was first authorized by the council in May, when the Public Works Department received approval to begin testing the concept. To make the system possible, Public Works staff worked with Western Systems, Inc. to standardize the city’s traffic signal cabinet design to the company’s “P-Plus” model. City engineers say standardization provides long-term efficiency, allowing staff to troubleshoot issues more quickly, reduce downtime, and improve roadway safety.
Western Systems submitted a formal quote on June 3 for $160,906.25, which includes equipment, shipping, and tax. The purchase qualifies as a sole-source procurement under Folsom’s municipal code because the city has already standardized its cabinets with Western Systems technology.
According to the staff report prepared by Public Works Director and City Engineer Rebecca Neves, sufficient funds are available in the Transportation Improvement Fund to cover the purchase. The action itself is considered exempt from the California Environmental Quality Act since it involves equipment acquisition rather than a construction project.
Folsom joins a growing list of Northern California cities—including Roseville and Elk Grove—deploying flashing yellow arrows to modernize traffic management and give drivers more flexibility at key intersections. City staff will continue to monitor the results of the trial once the new signals are installed to determine whether the program should expand to additional locations in the future.
How the signals work
The flashing yellow arrow system uses a four-light vertical head to communicate turn permissions. A steady red arrow requires drivers to stop, while a steady yellow warns of an impending change. The flashing yellow arrow gives drivers the option to turn left after yielding to oncoming traffic and pedestrians, while the green arrow provides a fully protected turn.
The California DMV Handbook already explains the device in its driver instruction materials, and both the Federal Highway Administration and the California Manual on Uniform Traffic Control Devices have cleared its use. Public Works officials say this helps ensure drivers are familiar with the meaning of the new signals before they are introduced locally.
City engineers project the change will reduce unnecessary delays, particularly during off-peak hours when left-turn lanes often sit empty waiting for a protected green. Studies show flashing yellow arrows can cut idling emissions by 9 to 12 percent by allowing vehicles to move more freely.
“Many jurisdictions, including neighboring cities, have implemented FYAs, creating regional consistency for drivers,” former Public Works Director Mark Rackovan wrote in the May staff report when the pilot was first considered. Elk Grove, Roseville, and Sacramento County have all expanded their use of flashing yellows in recent years, providing a foundation for Folsom to follow suit.
The approach also makes it easier for drivers to distinguish between protected turn phases and permissive ones, which engineers say helps with both safety and traffic management.
When the pilot program was first launched, the city committed to ensuring the public would understand how to use the new signals. That effort is expected to include outreach through pamphlets, online tutorials, and local media demonstrations before the signals go live.
The city initially studied up to 19 potential intersections for eligibility, but narrowed the trial to the four along Natoma Street due to infrastructure and compatibility needs. Installation of the new cabinets is expected to take place in the months ahead, with the first flashing yellow arrow in operation by late 2025 or early 2026. Results of the trial will be reported back to the City Council to determine if a citywide rollout is warranted.
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