What is the primary characteristic of the legal authority over public roadways in the U.S.?

The primary characteristic of the legal authority over public roadways in the U.S. is state governance. Each state has the power to manage and regulate its own roadways, which includes the authority to establish traffic laws, maintenance responsibilities, and infrastructure development. This state-level control stems from the U.S. Constitution, which prioritizes state rights in matters not expressly delegated to the federal government. While local governments can influence traffic regulations and road management within their jurisdictions, the overarching authority and funding are typically derived from state statutes and policies. Federal control plays a role primarily through funding and national guidelines but does not constitute the primary legal authority, making state governance the correct choice. Private ownership is not applicable in the context of public roadways, as they are intended for public use and access.