Route 123 (Massachusetts)

Route 123
Map of southeastern Massachusetts with Route 123 highlighted in red
Route information
Maintained by MassDOT
Length:	41.91 mi (67.45 km)
Major junctions
West end:	Route 123 in Cumberland, RI
	US 1 in Attleboro I‑95 in Attleboro I‑495 in Norton Route 24 in Brockton
East end:	Route 3A in Scituate
Location
Counties:	Bristol, Plymouth
Highway system
Massachusetts State Highway System Interstate US State ← Route 122A Route 124 →

Route 123 is a west–east state highway in southeastern Massachusetts. It crosses northern Bristol and Plymouth counties, crossing several highways along the way.

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. It crosses Route 152 and under the MBTA commuter rail tracks before making another northerly turn, this time at the end of Route 118.

From Attleboro, the route heads eastward into Norton. It crosses Route 140 at the town center, having a brief, 50-yard concurrency between the two. After passing Wheaton College, it continues through town, crossing I-495 at exit 10. The road then turns northward into Easton. In Easton, the road turns eastward again as it becomes concurrent with Route 106 for just over a mile, with Route 123 turning northeastward at the Five Corners intersection between the two routes and Bay Road. The route eventually meets Route 138, which it shares a short concurrency with before turning eastward again at Stonehill College.