The current paper is about bus transport process network synthesis. Unlike previously discussed urban traffic modelling and solution methods, here, it is presented as a novel application of the p-graph methodology, while exploiting the peculiarities of the problem. The focus is on the synthesis step, where the set of potentially feasible solutions is determined, in other words, the maximal bus transport process structure is generated. The classical process network instances together with their properties are adapted to this new application field, i.e. to meet the special requirements of the bus transport. First, the meaning of the material type nodes and the operating unit type nodes are described in details. A new axiom is given to complete the set of p-graph's axioms. In addition, the utilization of the conventional maximal structure and solution structure generation algorithms, they are extended to gain advantage of the new axiom and to generate the potential solution structure in a more effective manner. Based on the solution structures a mathematical programming model is generated containing the constraints and the objective function of the bus transport problem. Thus, the generation of the bus launching list is prepared. The solution method presented for bus transport problems meets the high level expectations of decision-makers, i.e. the resulting system is complete, flexible and robust.