RI 108 is a north/south extending from Point Judith in Narragansett to Kingston. The southern half is a four-lane undivided road called Point Judith Road that extends from Ocean Road to a rotary at Kingstown Road (RI 1A). The two routes are multiplexed for a few blocks, during which there is an interchange with US 1. Then, RI 1A splits off to the west as Main Street. RI 108 continues north along Kingstown Road to end at its intersection with Mooresfield Road (RI 138) in Kingston. Kingstown Road turns west and takes on the designation of RI 138 at the northern terminus of RI 108.