Changes

This option involves less walking along the motorway. From the city centre, take tram 7 in the direction south-east until the last stop (takes about 15 minutes, depending on the traffic). From there take bus 308, direction Veliki Mokri Lug (sometimes written as V.M.L.). After about ten minutes you will cross a bridge going over the motorway; get out at the next stop 100 meters later. From the bridge you will already see the petrol station where you want to go, which is about 200 meters walking. This petrol station is also located uphill. (This info is not entirely correct, I spent 4 hours while trying to get out of Belgrade. There is no way to reach the stop of 308 with Tram 7. You have to get off at Vukadin memorial or shortly Vuk and from there on, walk to a nearby kiosk and catch bus 6A, then go to the last stop Ustanicka and walk down the street. There you can catch 308 to VML. The gas station is a pretty good place to hitchhike, just don't be in it, cause there's just a few cars stopping and you'll be waiting quite a lot)

A sign saying "10 K.M." might be helpful in catching a local car which can take you to the first toll stop (a hitchhiking stop regularly used by locals) and out of the intense exhaust fumes.