Institute of Transportation, MOTC

The bridges in Taiwan have to be inspected regularly in every year. In practice, the routing and scheduling for bridge inspections depend on the experience of the decision maker, which is neither efficient nor effective. Therefore, in this study we propose an optimal routing and scheduling model with the objective of minimizing the total cost for bridge regular inspection. In addition, the model is formulated as an integer network flow problem with side constraints, which is characterized as NP-hard. To efficiently solve the realistically large problems occurring in pracitce, a heuristic algorithm is developed. Finally, we perform a case study using real data of bridge inspections from a Taiwan city to demonstrate and to elvaute the model and the solution algorithm. The results are good, showing that the model and the solution algorithm could be useful references for practices.