From the Executive Summary: "The 2020 National Strategy for Transportation Security addresses the security of 'transportation assets in the United States that… must be protected from attack or disruption by terrorist or other hostile forces….' The strategy presents a forward-looking, risk-based plan to provide for the security and freedom of movement of people and goods while preserving privacy, civil rights, and civil liberties. It identifies objectives to enhance the security of transportation infrastructure, conveyances, workers, travelers, cargo, and operations. The strategy consists of a base plan and four security plans, including aviation, maritime, surface, and intermodal systems. The Surface strategies (National Strategy for Public Transportation Security [NSPTS] and the National Strategy for Railroad Transportation Security [NSRTS]) that were previously annexed to the 2018 NSTS are now incorporated into the Surface modal plans. Specifically, the NSPTS was merged into the mass transit and passenger rail modal plans, and the NSRTS was merged into the freight and passenger rail modal plans."
U.S. Department of Homeland Security: https://www.dhs.gov/