Signal maintainers are professionals responsible for ensuring the proper functioning of communication and signaling systems, particularly in transportation networks like railways. They inspect, repair, and maintain equipment such as traffic signals, railroad signals, and communication devices to ensure safety and efficiency. These technicians work with various tools and technologies to troubleshoot issues and perform routine maintenance. Their role is crucial in preventing accidents and ensuring that signals operate correctly, allowing for smooth and safe operations in systems that rely on precise communication, such as public transit and air traffic control.