From the Executive Summary: "The Nation's transportation system is crucial to the U.S. economy and the overall quality of life for Americans from all walks of life. In today's increasingly complex and connected society, every critical infrastructure sector depends on a resilient transportation system that is safe, secure, reliable and efficient in the movement of people and goods; without it, most critical services cease to function. In recognition of this important role, the President directed the National Infrastructure Advisory Council (NIAC) to examine the resilience of the Nation's transportation sector to determine potential gaps and identify opportunities for the Federal Government to improve the sector's resilience and security. Throughout this study, infrastructure resilience is defined as the ability to reduce the magnitude or duration of disruptive events that is accomplished by anticipating, absorbing, adapting to, or rapidly recovering from the disruption. In simplest terms, resilient systems can maintain critical functions during a disruption and require less time and fewer resources to recover functions that have degraded."
National Infrastructure Advisory Council (U.S.): https://www.dhs.gov/national-infrastructure-advisory-council