 Route 123 is a continuation of R.I. Route 123, which crosses the state line between Cumberland, Rhode Island and Attleboro.In the South Attleboro section of the city, it crosses Routes 1 and 1A in quick succession, just south of the junction of the two and the start of the Attleboro-North Attleborough retail area.It continues eastward, crossing I-95 at exit 3 before turning northeastward, passing Capron Park and the former Attleboro High School building (now a branch of Bristol Community College) before reaching downtown Attleboro.