The deterioration of the U.S. highway system has received significant attention from scholars, industry practitioners, and policymakers over the last several decades. This growing interest has encouraged the production of multiple reports highlighting the challenges of enhancing system conditions in the long term. Because government agencies do not have sufficient resources to take care of roads in a timely manner, deterioration worsens, and available funds are primarily used for previously deferred maintenance and rehabilitation activities. The current work seeks to gain insight into the dynamics of capital investments and maintenance expenditures in U.S. road infrastructure. Based on a system dynamics model, the authors argue that the highway system is stuck in a capability trap (failure to achieve sustained improvements) because authorities tend to promote short-term reactive efforts over long-term proactive actions. The study contributes to the existing literature by highlighting the feedback mechanisms that connect maintenance and rehabilitation expenditures with aging and deterioration processes. Building on a counterfactual analysis between 1994 and 2010, the research reveals that incentivizing preventive practices not only enhances system conditions but also reduces major rehabilitation expenses and, in the long term, frees up resources for capacity expansion. Conclusions point to the difficulties associated with escaping the trap and the impacts of implementing reactive and proactive policies throughout the highway system. (C) 2017 American Society of Civil Engineers.