Operational Optimization of Urban–Rural Integrated Passenger–Freight Bus Service Based on Social Welfare Maximization

As an emerging transportation mode, the integrated operation of passenger and freight services on urban–rural bus routes plays a pivotal role in promoting resource circulation between urban and rural areas. In recent years, declining bus ridership and tightening fiscal subsidies have led to frequent service suspensions. It is of significant importance to investigate the optimization of operational schemes to ensure the sustainable operation of urban–rural buses while maximizing the system’s social welfare output. This paper constructs an operational optimization model with the objective of social welfare maximization, designs a simulated annealing algorithm for solving it, and validates it through a case study. The research finds the following: (1) The optimized model resulted in a 28.46% increase in passenger volume, a 181.25% increase in parcel acceptance volume, a 20.15% reduction in government subsidies, and a 70.42% improvement in total social welfare, demonstrating significant optimization effects. (2) While increased government subsidies promote social welfare output, the positive effect diminishes substantially beyond an optimal amount, at which point further increases become uneconomical. (3) An increase in the passenger travel time value coefficient will accelerate the reduction in social welfare output, which imposes higher demands on enhancing the targeting of service objects.