How do dial-up modems operate in a traffic signal system?

Dial-up modems operate by utilizing telephone lines to transmit data. In a traffic signal system, this means that the modem connects to a standard landline telephone system, allowing data from various components such as traffic controllers and sensors to be sent to a central computer for processing.

This method is particularly relevant in situations where wired internet connectivity is not available or feasible. The advantage of using dial-up modems is their ability to provide a reliable communication channel for essential system data, even in remote locations where newer communication technologies may not be implemented.

The other options represent different technologies or methods for data communication. For example, connecting directly to traffic cameras typically relies on high-bandwidth connections, while cellular networks may involve more sophisticated equipment than dial-up modems are designed for. GPS signals primarily serve for location tracking and navigation, not for transmitting the operational data needed for traffic signal control. Understanding the specific function of dial-up modems in this context highlights their role in connecting systems effectively, even if it is through an older technology.