Simulation of Impact of Strategy Development Frameworks on Performance of Transportation Infrastructure

Decision-making processes for investment in transportation infrastructure and, ultimately, the investment decisions themselves are central to the performance of transportation systems. Perhaps equally important for performance is the governance framework within which decisions are made. However, because of the complexity of the relationships between frameworks and performance, the evaluation of frameworks is challenging. This paper decomposes some elements of governance of transportation infrastructure into strategy development frameworks and through an agent-based simulation model provides a deeper understanding of the relationships between strategy development frameworks and system performance. A strategy development framework for transportation can be characterized by the infrastructure ownership structures, cross-modal and cross-sectoral linkages, revenue sources, decision-making processes for resource allocation, and the geographic scales of the organizations responsible for making infrastructure investments. With the dimensions of a strategy development framework as inputs, agents in a simulation framework make investments in an infrastructure network over time. This study used the national intercity roadway network of Portugal as the context. The results demonstrated the value of using simulation models of complex transportation systems to inform the decisions not only of planners but also of stakeholders who designed strategy development frameworks, for example, by predicting the relative performance of state ownership versus concession arrangements, tolling versus general taxation, and centralized versus decentralized control of investment decisions. Such a tool was viewed as particularly important given the ongoing reorganization of the Portuguese transportation sector, including an increasing reliance on concession agreements, highway tolls, and subnational government participation.