At several non-controlled aerodromes, Aerodrome Flight Information Service, AFIS is provided to give information for the safe and efficient conduct of flights. The AFIS unit issue instructions and information to aircraft moving on the manoeuvring area or apron to assist pilots in preventing collision between aircraft and vehicles and obstructions. The movements of vehicles or pedestrians on the manoeuvring area are subject to authorization by the AFIS unit. To give meteorological information and information about aerodrome conditions are also included in the duties. The AFIS unit also relay Air Traffic Control clearances issued by ATC unit. At some AFIS aerodromes a Traffic Information Area, TIA and a Traffic Information zone are established to increase safety.