Public transport in Slavonia is, to put it mildly, difficult. It is infrequent, particularly on weekends and holidays. Come summer, when kids aren’t traveling to school, many routes are cancelled entirely. If you must use public transport, the bus is more reliable than the train. There are around ten daily buses between Zagreb and Osijek (4 hours, 125 Kn) and a couple of daily buses making the 45-minute trip from Osijek to Vukovar, or to Đakovo an hour away. A great resource for comparing routes is www.getbybus.com.
Đakovo Bus Station. Splitska bb, Ðakovo, Osjecko-Baranjska. 060/302–030.
Osijek Bus Station. Bartola Kašića 70, Osijek, Osjecko-Baranjska. 060/353–353.
Vukovar Bus Station. Ulica Kardinala Alojzija Stepinca 3, Vukovar, Vukovarsko-Srijemska. 060/337–799.