Optimizing loading space locations for walkable city centers

The creation of pedestrian zones in city centers has a number of positive impacts on the environment and human activities. At the same time, for the revitalization of city centers, goods must be delivered smoothly to stores, offices, and other places of activity. Since pedestrian zones often restrict the movement of freight vehicles, the increased distance between loading spaces and delivery destinations may lead to a decrease in delivery efficiency. Therefore, the balance between the creation of pedestrian zones and the maintenance of delivery efficiency should be carefully discussed. To quantitatively evaluate this balance, this study performs an optimal location analysis of loading spaces of freight vehicles, explicitly considering different pedestrianization plans. We first develop a multi-agent discrete event simulation that deals with the interactions between delivery agents through the dynamics of the capacity and availability of loading spaces. Based on the simulation model, we formulate an optimal location problem of loading spaces to minimize the total time of delivery activities, including driving, walking, and service at the delivery destination. This optimization problem considers a pedestrian zone scenario as a constraint that restricts the location of loading spaces, allowing for an optimal location analysis under different walkability plans. We apply this approach to the city center network of Omiya City, Japan, and analyze delivery efficiency under the actual pedestrian zone plans.