Trade-Off Analysis Approach for Multiobjective Transportation Investment Decision Making

Abstract

Transportation planning is multidimensional, complex, and dynamic in nature. The decision-making process often involves multiple stakeholders with conflicting preferences. Effective decision outcomes can only be reached by explicitly addressing such conflicts. Over the last several decades, optimization techniques have been used for project-selection decisions to achieve maximized overall returns on investments. The existing methods for project selection capable of conducting trade-off analyses mainly focus on assessing trade-offs between project construction time, duration, and cost, as well as swapping between transportation agency costs and user costs. However, they have largely not addressed impacts on the overall economic returns by changing a few important decision factors such as differentiating relative importance of various transportation performance goals and measures, and different types of highway facilities, and further relaxing the budget constraints by management programs dealing with physical facilities and system operations while keeping the total budget unchanged. This paper introduces a trade-off analysis approach that uses a multicommodity minimum-cost network (MMCN) model to establish traffic details for the transportation network needed for estimating the benefits of implementing a single project or multiple projects jointly, and a surrogate worth trade-off (SWT) method for multiobjective project selection based on the estimated project benefits. A computational study has revealed that the proposed trade-off approach can generate noninferior solutions and increase the total benefits by 18–20%.