46 U.S.C. § 55601 — United States marine highway program

(a) Establishment. (1) The Department of Transportation runs a program called the "United States marine highway program." (2) While running it, the Secretary of Transportation may work with ports, state^* transportation departments, local governments, other public agencies, and private companies to build the roads, docks, and other facilities that support water transportation, and may create ways to measure the program's success.

(b) Marine Highway Transportation^* Routes. (1) The Secretary may designate a water route as a "marine highway transportation route," or change an existing designation, if the route gives a real, workable alternative to land transportation, eases road congestion, promotes marine highway transportation, or uses vessels documented under chapter 121 — and if a state, territory, metropolitan planning organization, port authority, non-federal navigation district, or Tribal government^* asks for the designation or change. (2) The Maritime Administrator must decide whether to grant the request within 180 days of receiving it. (3) The Administrator must tell the requester the decision within 14 days after making it.

(c) Map of Marine Highway Program Routes. (1) The Maritime Administrator must make a public map showing all marine highway routes — coastal, inland, and at sea — and update it whenever a route is designated or changed. (2) The Administrator must work with NOAA to add this map to the Marine Cadastre.

(d) Assistance. (1) The Secretary may give grants, or sign contracts or cooperative agreements, to help eligible groups build a marine highway project, if the project meets the route criteria above and grows or promotes marine highway transportation or its use by shippers. (2) To apply, an eligible entity must submit an application including: a full description of the route, its supporters, why it's needed, and how success will be measured (like cargo volume or safety gains); proof that the project is financially workable and that the money will be spent well; and any other information the Secretary requires. The Secretary may first require a shorter "pre-proposal," and must give feedback on it within 30 days — though an applicant can still submit a full application even without encouragement. The Secretary cannot require separate applications for the route designation and for the funding itself. After awarding money, the Secretary may also give feedback to help future applications, if asked. (3) The Secretary must post a public notice about available grants within 60 days after that year's funding law is enacted, and must award the grants within 270 days after that. (4) Normally, no more than 80 percent of a project's funding may come from federal sources — except the Secretary may raise that share above 80 percent for a Tribal government applicant or for a project in a rural area. (5) When awarding money, the Secretary must give preference to projects that are the most financially solid and that ask for the smallest federal share. (6) Money that isn't spent within five years, or that gets returned, stays available for the Secretary to award to other projects. (7) The Secretary cannot give assistance unless satisfied that the applicant has enough non-federal matching money, that the project will finish without unreasonable delay, and that the applicant has legal authority to carry it out. (8) The money cannot be used to improve infrastructure outside the United States, or — unless truly necessary for the project — to raise sunken vessels, build buildings, or buy land. (9) The Secretary must try to spread the grants fairly across different parts of the country geographically. (10) "Eligible entity" means a state, a part of a state, or a local government; a U.S. metropolitan planning organization; a U.S. port authority; a Tribal government; or a U.S. private operator or facility owner (including an Alaska Native Corporation^*) that has an endorsement letter from whoever requested the route.