City of Rohnert Park

The Flashing Yellow Left-Turn traffic signal helps provide safer left-turns for drivers and improve the flow of traffic. The Flashing Yellow Arrow signals replaced the left arrow signals for left-turns at some intersections.

View the following video from Santa Rosa to see how the flashing yellow left-turn signal will operate:

Credits: City of Santa Rosa

Benefits of Flashing Yellow Arrow

• Reduces delays for drivers
• Can reduce left-turn collisions by up to 20%
• Allows more opportunities for left turns to be made compared to existing signals
• Consistency with other jurisdictions in California

How to Use a Flashing Yellow Arrow

It's simple! A Flashing Yellow Arrow means to first YIELD to oncoming vehicles, bicyclists, and pedestrians, then turn left with caution. Remember, oncoming vehicles, bicyclists, and pedestrians will have the right-of-way. The Flashing Yellow Arrow will change to a solid yellow arrow — that means what it has always meant, that the light is about to turn red and you should prepare to stop.

Signal Display Changes

Location of the First Flashing Yellow Left-Turn Signals Installed in Rohnert Park

• Camino Colegio & East Cotati Avenue
• Commerce Boulevard & Alison Avenue
• Commerce Boulevard & Avram Avenue
• Golf Course Drive & Country Club Drive
• Golf Course Drive & Labath Avenue
• Snyder Lane & Eleanor Avenue

Vehicle detection is a system that makes intersections operate better by telling the computer where vehicles are in relation to the intersection (if they are waiting or approaching), which then lets the computer know to give that vehicle a green light. This is why, on approaching an empty intersection, the light will sometimes turn green before the vehicle has actually reached the intersection.

Video: The City of Rohnert Park employs video vehicle detection at a vast majority of its intersections. Our video detection in Rohnert Park is very precise. It will detect cars, golf carts, and even bicycles using a combination of video feed and radar to limit missed detection. These vehicle detection cameras DO NOT store video because its only purpose is to alter the intersection's computer that a vehicle has arrived or is arriving and will need a green light soon.

Loops: An older technology used for vehicle detection are in ground loops. Loops are generally a 3 to 6 foot square, rectangle, or circle that detect vehicles by sensing the metal in the vehicles. You may notice them near intersection approaches. That is what those squares in the asphalt do.

What is it? Rohnert Park's Advanced Traffic Management System (ATMS) is called KITS and was developed by Kimley-Horn and Associates, Inc. to get the most out of existing traffic networks. Just like any new software, it is constantly under development to keep improving. This system allows us to view and operate our intersections without leaving the office. It also records every signal change so if a resident has a complaint about a signal, and they know the relative time of the problem, we can easily determine how to fix it. The ATMS is not a magic cure to all that will make every light you approach turn green, but it does help shave off seconds at lights and minutes overall for daily travel time which saves Rohnert Park residents thousands of hours per day.

A large portion on our intersections on Golf Course and Rohnert Park Expressway are coordinated intersections. This means that, during commute hours, they are timed together to give drivers on the thoroughfares a string of green lights. KITS has an option called Kadence that actually changes the intersection timings based on the volume of traffic flow to get more cars through and reduce total commute times. A drawback of coordinating intersections is that the smaller side streets and left turns generally get shorter green times because the system caters to the greater good in terms of travel time.

Rohnert Park's ATMS has been mostly implemented on Rohnert Park Expressway and Golf Course Drive. Currently, we have 27 intersections on our system with plans to add 10 more intersections to our ATMS.

Have you ever wondered what those yellow ribbons are around the traffic signals? Well, you aren’t seeing things. Those yellow marks are reflective yellow tape to help better outline the traffic signals. This method helps with making the signal heads highly visible at night, so if the signals lose power (like during a power shut off), cars will see the reflective tape and hopefully realize they are approaching a signal at that point.