Year around it is possible to travel by bus from Bern to Vukovar, the bus goes via Zagreb where passenger change bus, Click on the info icon in the timetable below to see operation dates of bus. On the weekdays where there is no bus from Vukovar you can choose to travel from Bern to Zagreb, and then take a bus from Zagreb to Vukovar from the bus station in Zagreb. The The travel time for the 1280 km long bus route from Bern to Vukovar is about 18 hours. If you plan to travel back to Bern you should by a return ticket as it is cheaper, timetable for returning buses you can see here. If the timetable to and from Vukovar does not match your travel plans, the cheapest travel option is probably to buy return ticket Bern – Zagreb – Bern, and then a return ticket for the bus between Zagreb and Vukovar.