Integrated, demand-responsive passenger and freight transport (IDRT) potentially provides flexibility and higher service frequency in areas of low demand due to economies of scale, while reducing negative traffic-related externalities such as pollutant emissions, noise emissions or accidents. However, to allow for efficient operations in terms of minimum travel distances, short customer waiting times, and high vehicle utilization rates, IDRT requires effective rebalancing strategies that balance supply and demand capacities by strategically positioning vehicle resources in the operational area. Therefore, we propose a rebalancing strategy for IDRT and measure its effectiveness through an agent-based simulation model. To evaluate our approach, we compare the rebalanced IDRT with a static scenario with backhauls to a central depot. Our results indicate that the proposed rebalancing approach can outperform a system without rebalancing by up to 15.1% in terms of total fleet kilometers and 30% in terms of passenger waiting time.