Massachusetts Route 3A

Route 3A marker
Route 3A
Map
Route 3A highlighted in red
Route information
Maintained by MassDOT
Length97 mi[1] (156 km)
Existed1926–present
Southern section
Length53.392 mi[1] (85.926 km)
South end Route 3 in Plymouth
Major intersections US 44 in Plymouth
Route 53 in Kingston
Route 53 in Quincy
North end I-93 / US 1 / Route 3 / Route 203 in Boston
Northern section
Length22.5043 mi[1] (36.2172 km)
South end I-95 / US 3 / Route 128 in Burlington
Major intersectionsLowell Connector in Lowell
Route 110 in Lowell
Route 113 in Tyngsborough
North end NH 3A in Hudson, NH
Location
CountryUnited States
StateMassachusetts
CountiesPlymouth, Norfolk, Suffolk, Middlesex
Highway system
Route 3 Route 3B
Route 6N.E. Route 7

Route 3A is a 97-mile-long (156 km) state highway in eastern Massachusetts, which parallels Route 3 and U.S. Route 3 from Cedarville in southern Plymouth to Tyngsborough at the New Hampshire state line.

Route 3A has two major posted segments, separated by a lengthy concurrency with Route 3 and US 3. Its southern portion parallels Route 3 from Cedarville in southern Plymouth to Neponset in the Dorchester area of Boston. Towns and cities that Route 3A traverse along its path include Plymouth, Kingston, Duxbury, Marshfield, Scituate, Cohasset, Hingham, Weymouth and Quincy.

North of Neponset, Route 3A runs, unsigned, concurrently with Route 3 and U.S. Route 3 to Burlington, before separating again (MassDOT counts the mileage along MA 3 and US 3 between the two sections as part of MA 3A mileage).

The northern portion of Route 3A parallels U.S. Route 3 in northwestern Middlesex County. It stretches from Interstate 95 (Route 128) in Burlington to the New Hampshire state line, where it continues as Route 3A.