Why do I have to stop? Why are signals so poorly synchronized?
Intersection signals are coordinated, or synchronized with each other to reduce stops and delay for the major traffic movements. Coordinating signals require that all signals be programmed with a common cycle length, which is the amount of time it takes a signal to sequence through all traffic movements one time.

The quality of movement through a series of traffic signals depends on the spacing between signals, the speed of traffic, the cycle length, and the amount of traffic. Signals along main arterial streets are generally coordinated with each other during the day, when there are heavy traffic flows. It is often not possible to progress traffic in both directions because of poor spacing between traffic signals. Sometimes it is necessary to choose one direction to progress.

When two-way progression is not possible, the City often uses computerized traffic modeling to find coordinated timing plans that decrease the total delay and stops for all users of the system. Traffic turning onto or off of a side street is generally not progressed, and turning vehicles can usually expect to stop at the next signal.

Specific questions about signal progression should be referred to the Traffic Engineering Division at 707-543-3814.

Show All Answers

1. How are speed limits established and how can I reduce or increase the speed limit on a particular street?
2. Can the City install "Children at Play" or "SLOW" signs on my street?
3. Can the City install a deer crossing sign at a particular location?
4. Can I get red curb painted in front of the fire hydrant by my house?
5. Can the City paint red curb so I can see getting out of a driveway, street or parking lot?
6. How can I get a stop sign installed on a neighborhood street to slow speeders down?
7. What is a commercial vehicle prohibition?
8. How can I get a radar speed feedback sign on my street?
9. How long can a car stay parked on the street?
10. How does a signal operate? Is a specific signal operating correctly?
11. How does a signal operate? Is a specific signal operating correctly?
12. Why do I have to stop? Why are signals so poorly synchronized?
13. Why do I have to wait so long after I stop at a specific signal?
14. Why isn’t there enough green time to get the traffic through the signal for a specific movement?
15. How do I get a new signal installed?
16. How do I find how much traffic there is at a specific location, or how many accidents there have been?
17. How do I find how a signal was operating at a specific time and date, and if it was operating correctly?
18. How does a pedestrian signal work?