The central government needs to help coordinate efforts to remove thousands of illegally placed advertising billboards around Athens in order to do away with a threat to drivers, said Giorgos Patoulis, the mayor of Maroussi, northern Athens. «There needs to be a central effort. What do you tell the father whose child has been killed on Kifissias Avenue, outside the limits of Maroussi?» said Patoulis, whose municipality has been removing billboards this week. According to some estimates, some 15,000 illegal billboards tower over the roads in the Athens area. Many of them obstruct road signs, stoplights and other vital traffic signals. Municipalities often claim they do not have the resources to appoint crews to remove the billboards. Other sources pointed out the billboards are a major revenue source, with one street-side advertisement costing up to 15,000 euros per year. According to one university study, 12 percent of road traffic accidents are due to drivers’ attention being diverted by large billboards.