Selecting an optimal contractual payment model for Istanbul's public bus operators using non-linear mathematical programming

In this study, an optimum payment model is suggested for Istanbul's public bus transport operators by modelling the expectations of passengers, operators and the transport authority. Their expectations also involve non-linear relationships, hence a non-linear mathematical programming is utilized in the paper. The commercial payment, gross-cost and performance-based gross cost payment models are the alternatives to be considered instead of the net-cost model due to its service quality problems in Istanbul's context. According to the model results, a gross cost payment model is recommended for Istanbul. By offering a consensus-based middle ground between the transport actors, the model provides a way for improvement in public transport service provision especially for developing cities where regulatory and institutional context is hard to change.