Changes

The other option is to take bus no. 7 (same bus station across the street from Futoska pijaca market), and get off just before it turns right (you can't know when it will turn right, so just take off after the turn, and then walk back to the main road). There's a city bus depot there, so just hitchhike in front of it. Another good option to get to Croatia is to start South from Novi Sad and then to go West. Perfect option to catch the highway to Zagreb :  To start off, catch bus 9A (there's a bus stop right after the bridge going to the Fortress, but probably also another one within the city). Get off at the final stop, on road 21. Then walk for 5 minutes and you will find a perfect spot with a large area for cars to stop. You will see it anyway, because the bus passes it before turning around for the official bus stop (you can try to ask the driver to let you get off while he is turning around as it will save you the 5-minute walk). Then your best shot is probably to find someone to take you to Ruma. There, you can hitch hike again at the highway toll and try to find someone to take you to Croatia. It is not an extremely busy road, but cars are going very slow since they must stop for the toll, which makes it a good spot.