Belgrade has an excellent network of long-distance buses, connecting it to all parts of Europe. The Central Bus Station, is close to the city centre. The station has exchange offices, ATMs and left luggage office. Arrivals are physically separated from the station building, they are located across the street, next to a park. You can find a tourist info centre at the neighbouring railway station. Our advice is to look out for notorious pickpockets and taxi crooks around station, and if you look our section about transportation in the city, you will find majority of transport satisfying and not expensive.
The city airport, Nikola Tesla, is 18km away from the city centre, making it very accessible. Although there are a few bus routes to the airport (the A1 is the most frequent, with stops in New Belgrade, Savski Trg and Slavija Trg, and the 300din fare can be paid to the driver), the easiest option is taking a taxi. Our advice is to make sure you rent one through the official taxi stand in the arrivals gate, with a fixed fare.
The less known and much cheaper airport in Serbia is Constantine the Great in Niš. And although you can enjoy the cheap transportation via Ryanair and the likes, if your final destination is Belgrade, you will have to add another 3 hours to your journey.
Belgrade lies at the intersection of E-70 and E-75 motorways. Foreign drivers in Serbia need an international driving license, vehicle registration certificate, and insurance policy. Driving licenses issued in EU are recognized in the Republic of Serbia, while other driving licenses must be accompanied by an International Driving Permit (IDP), on a reciprocity basis.
An international driving permit is issued based on the International Convention on Road Traffic (Vienna, 1968) and in accordance with the provisions of the road traffic safety laws and regulations of the Republic of Serbia. You cannot miss Belgrade, because the motorway runs through the city. The speed limit in the city is set at 60 km/h unless otherwise indicated by speed signs.
http://www.bas.rs/basweb_eng/redvoznje.aspx?lng=en(only for timetables)