The southern loop portion of Route 154 in Old Saybrook, from its beginning at Saybrook Manor (milepost 0.00) to the east junction with Old Boston Post Road in Old Saybrook Center (milepost 6.10) is a state scenic road. This portion of Route 154 serves the borough of Fenwick. The section of Route 154 in the town of Haddam (9.16 miles long) is also a state scenic road. This portion of the route runs alongside the west bank of the Connecticut River.