Abstract for: Understanding the US Highway System: A System Dynamics Perspective

Over the last years, a series of reports and academic studies throughout the country has highlighted the decline of the U.S. highway system. Some scholars have employed System Dynamics (SD) as a means to understand the complexity associated with maintaining and rehabilitating existing highways. They have also explored the challenges of investing in new road infrastructure. However, these studies have not fully addressed the issues related to the lack of funding for infrastructure from an endogenous perspective. Building on previous studies and taking into account official reports, we have built a simulation model to examine why road infrastructure is in a continuous state of deterioration and why governments have not been able to make sustainable capital expenditures so as to improve system performance. Although the model is only a preliminary product of an ongoing investigation and is limited in many ways, it properly replicates reality and allows to explain the increasing operational expenditures in the U.S. road infrastructure. Our results show that the revenues generated by gas-related taxes are not enough to cover the system expenses. As a result, the annual gap between expenditures and revenues keeps widening because repairing old pavements is more expensive than maintaining new highways.