The driver rostering problem (DRP), arising in public bus transport companies, aims to generate for each driver a roster while management considerations, labor laws, and desires of drivers have to be satisfied. Optimal rosters are characterized by maximal satisfaction of drivers, minimal difference of overtime among all drivers, and minimal number of unassigned duties. The DRP is mostly solved sequentially due to its high complexity, namely firstly the rota scheduling problem, and secondly the duty sequencing problem. However, this method may generate sub-optimal rosters. In order to avoid a sub-optimal solution, the paper discusses an integrated DRP, which is solved with a duty-block network approach for real-world instances and compared with a solution of a heuristic-based integrated DRP.