grounded with a heavy bare copper or copper-clad steel wire running down the pole, attached to the metal pin supporting each insulator, and at the bottom connected to a metal rod driven into the ground. Some countries ground every pole while others only ground every fifth pole and any pole with a transformer on it. This provides a path for leakage currents across the surface of the insulators to get to ground, preventing the current from flowing through the wooden pole which could cause a fire or shock hazard. It provides similar protection in case of flashovers and lightning strikes. A surge arrester (also called a lightning arrester) may also be installed between the line (ahead of the cutout) and the ground wire for lightning protection. The purpose of the device is to conduct extremely high voltages present on the line directly to ground. If uninsulated conductors touch due to wind or fallen trees, the resultant sparks can start wildfires. To reduce this problem, aerial bundled conductors are being introduced. Communication cables The communications cables are attached below the electric power lines, in a vertical space along the pole designated the communications space. The communications space is separated from the lowest electrical conductor by the communication worker safety zone, which provides room for workers to maneuver safely while servicing the communication cables, avoiding contact with the power lines. The most common communication cables found on utility poles are copper or fibre optic cable (FOC) for telephone lines and coaxial cable for cable television (CATV). Coaxial or optical fibre cables linking computer networks are also increasingly found on poles in urban areas. The cable linking the telephone exchange to local customers is a thick cable lashed to a thin supporting cable, containing hundreds of twisted pair subscriber lines. Each twisted pair line provides a single telephone circuit or local loop to a customer. There may also be fibre optic cables interconnecting telephone exchanges. Like electrical distribution lines, communication cables connect to service drops when used to provide local service to customers. Other equipment Utility poles may also carry other equipment such as street lights, supports for traffic lights and overhead wires for electric trolleys, and cellular network antennas. They can also carry fixtures and decorations specific for certain holidays or events specific to the city where they are located. Solar panels mounted on utility poles may power auxiliary equipment where the