ferry service linking Providence and Newport (already connected by highway) funded by grant money from the United States Department of Transportation. Though the service was popular with residents and tourists, RIPTA was unable to continue after the federal funding ended. Service was discontinued . The service resumed in 2016 and has been successful. The privately run Block Island Ferry links Block Island with Newport and Narragansett with traditional and fast-ferry service, while the Prudence Island Ferry connects Bristol with Prudence Island. Private ferry services also link several Rhode Island communities with ports in Connecticut, Massachusetts, and New York. Rail The MBTA Commuter Rail's Providence/Stoughton Line links Providence and T. F. Green Airport with Boston's South Station, with an intermediate stop at Pawtucket/Central Falls and several stations in Massachusetts. The line was later extended southward to Wickford Junction, with service beginning April 23, 2012. The state hopes to extend the MBTA line to Kingston and Westerly, as well as explore the possibility of extending Connecticut's Shore Line East to T.F. Green Airport. Amtrak's Acela Express stops at Providence Station (the only Acela stop in Rhode Island), linking Providence to other cities in the Northeast Corridor. Amtrak's Northeast Regional service makes stops at Providence Station, Kingston, and Westerly. Aviation Rhode Island's primary airport for passenger and cargo transport is T. F. Green Airport in Warwick, though Rhode Islanders who wish to travel internationally on direct flights and those who seek a greater availability of flights and destinations often fly through Logan International Airport in Boston. Limited access highways Interstate 95 (I-95) runs southwest to northeast across the state, linking Rhode Island with other states along the East Coast. I-295 functions as a partial beltway encircling Providence to the west. I-195 provides a limited-access highway connection from Providence (and Connecticut and New York via I-95) to Cape Cod. Initially built as the easternmost link in the (now cancelled) extension of I-84 from Hartford, Connecticut, a portion of U.S. Route 6 (US 6) through northern Rhode Island is limited-access and links I-295 with downtown Providence. Several Rhode Island highways extend the state's limited-access highway network. Route 4 is a major north–south freeway linking Providence and Warwick (via I-95) with suburban and beach communities along Narragansett Bay. Route 10 is an urban connector linking downtown Providence with Cranston and Johnston. Route 37 is an important east–west freeway through Cranston and Warwick and links I-95 with