 It consists of measuring, control and signaling devices, located in zones where driving conditions may vary—at interchanges, near viaducts, bridges, and in zones where fog is known to occur.The system comprises variable traffic signs used to communicate changing driving conditions, possible restrictions and other information to motorway users.There are numerous rest areas along the motorway, providing various types of services ranging from simple parking spaces and restrooms to filling stations, restaurants and motels.