What is the standard voltage for traffic signal systems in many jurisdictions?

The standard voltage for traffic signal systems in many jurisdictions is 120 volts AC. This voltage is typically used for the primary power supply to the traffic signal controller and associated equipment, allowing for proper operation and compatibility with the electrical infrastructure found in most urban areas.

Using 120 volts AC ensures that the signals can handle the necessary power while providing enough current to operate the lights effectively. It also allows for ease of integration with existing electrical systems and simplifies maintenance and troubleshooting since most electricians and technicians are familiar with this voltage level.

While other voltage levels might be used in specific applications, such as 12 volts DC for some internal components or 48 volts DC for certain signal applications, 120 volts AC remains the prevalent standard for the overall traffic signal system operation.