Optimal number and scheduling of freeway bus fleet

Abstract Optimizing the number of freeway buses and preparing a quality schedule fundamentally influences the performance of a transportation company. The cost of over-covering or uncovering duty and of buses waiting for dispatch in a station is important practical issues that remain unsolved. A feasible solution should simultaneously consider the number of buses required to ensure high service capacity, and effective bus scheduling. Freeway bus scheduling is a short-term issue that is subject to time pressure. In particular, immediate rescheduling is generally needed when traffic jams or accidents occur. Finding solutions that obtain both the optimal number of buses and the optimal schedule is a complicated NP-hard problem. This study uses genetic algorithm that simultaneously considers the number of freeway buses and the schedule. The proposed model obtains an approximately optimal solution in a short time. The proposed model is tested by the bus timetable of a current transportation company, revealing that the scheduling problems can be solved quickly and correctly, improving the firm’s performance by 22.12%.