The role of the U.S. Coast Guard in waterway transportation is to provide security and safety on navigational routes.

The U.S. Coast Guard plays a crucial role in ensuring the security and safety of maritime transportation, including overseeing navigation safety, conducting search and rescue operations, enforcing laws, and preventing environmental hazards in U.S. waters. They are also involved in monitoring vessel compliance with safety regulations, but they do not typically manage port operations or build infrastructure.