 Route 4 , also known as the Colonel Rodman Highway , is a 10 @.@ 37 @-@ mile ( 16 @.@ 69 km ) long numbered state highway located in Washington County and southern Kent County , Rhode Island , United States . The route is a major north – south freeway in the southern Providence metropolitan area , directly linking Providence with eastern Washington County , the beaches of Narragansett and South Kingstown , and the city of Newport . Route 4 begins as a two @-@ lane divided highway at an intersection with U.S. Route 1 ( US 1 ) in the town of North Kingstown , becoming a limited @-@ access freeway after 1 @.@ 89 miles ( 3 @.@ 04 km ) . The route has four numbered interchanges before terminating in the city of Warwick , where the northbound lanes merge into Interstate 95 ( I @-@ 95 ) . 
