While the number of deliveries has been increasing rapidly, infrastructure such as parking and building configurations has changed less quickly, given limited space and funds. This may lead to an imbalance between supply and demand, preventing the current resources from meeting the future needs of urban freight activities.
A study by the Department of Civil and Environmental Engineering, University of Washington, Seattle, aimed to discover the future delivery rates that would overflow the current delivery systems and find the optimal numbers of resources. To achieve this objective, the researchers introduced a multi-objective, simulation-based optimization model to define the complex freight delivery cost relationships among delivery workers, building managers, and city planners based on the real-world observations of the final 50 ft of urban freight activities at an office building in downtown Seattle, Washington, USA.
There were three main objectives in the problem formulation:
- Minimize the costs for delivery workers.
- Minimize the costs for building managers.
- Minimize the costs for city planners.
Their discrete-event simulation model with increasing delivery arrival rates showed an inverse cost relationship between delivery workers and building managers. In contrast, the cost of city planners decreased up to 10 deliveries/hour and then increased until 18 deliveries/hour. At that point, costs increased for all three parties and overflew the current building and parking resources. The optimal numbers of resources that would minimize the costs for all three parties were then explored by a non-dominated sorting genetic algorithm (NSGA-2) and a multi-objective, evolutionary algorithm based on decomposition (MOEA/D).
The study sheds new light on a data-driven approach for determining the best combination of resources that would help the three entities work as a team to better prepare for the future demand for urban goods deliveries.
Source: Haena Kim, Anne Goodchild, Linda Ng Boyle, Modeling the competing demands of carriers, building managers, and urban planners to identify balanced solutions for allocating building and parking resources,
Transportation Research Interdisciplinary Perspectives,
Volume 15, 2022, 100656, ISSN 2590-1982,