Cities and towns in Puerto Rico are interconnected by a system of roads, freeways, expressways, and highways maintained by the Highways and Transportation Authority under the jurisdiction of the U.S. Department of Transportation, and patrolled by the Puerto Rico Police Department. The island's metropolitan area is served by a public bus transit system and a metro system called "Tren Urbano" (in English: Urban Train). Other forms of public transportation include seaborne ferries (that serve Puerto Rico's archipelago) as well as "Carros Públicos" (private mini buses).