Route 138 is a numbered State Highway running 48.3 miles (77.7 km) in Rhode Island. It is the longest state numbered route in Rhode Island, and the second longest highway after US 1. Route 138 begins in Exeter at the Connecticut state line in the west and runs to the Massachusetts state line in Tiverton in the east, and is the only state-numbered route to completely cross Rhode Island. Route 138 also keeps the same route number on the other side of both state lines.

U.S. Route 1 (US 1) is a major north–south U.S. Route through the U.S. state of Rhode Island, specifically within the Providence metropolitan area. Staying close to the Atlantic Ocean and Narragansett Bay, it is a longer route than Interstate 95 (I-95), and many portions are a four-lane divided highway.