Massachusetts Route 1A
Route 1A is a north-south state highway in Massachusetts, United States. It is an alternate route to U.S. 1 with three signed sections and two unsigned sections where the highway is concurrent with its parent. Due to the reconfiguration of tunnel interchanges brought on by the completion of the Big Dig, Route 1A is discontinuous in the downtown Boston area. Vehicles entering Downtown Boston via the Sumner Tunnel must take I-93 north to the exit for Government Center and make a U-turn to access the entrance ramp to I-93 south and vice versa.
Route description
Rhode Island border to Attleboro
A short segment of Route 1A, in length, in Attleboro runs from U.S. Route 1A at the Rhode Island border through a junction with Interstate 95, before heading north and merging with Route 1. The entire length of this segment is known as Newport Avenue.North Attleborough to Dedham
This segment of Route 1A extends roughly north from North Attleborough to Dedham, passing through the towns of Plainville, Wrentham, Norfolk, Walpole, Norwood and Westwood on the way. Prior to its realignment along I-95 and I-93, Route 1 continued north along the Providence Highway towards Boston at the junction of Route 1A and that road.Boston to Salisbury
History
Initially, Route 1A ran along part of its present-day route between the New Hampshire state line and Revere. It then turned west along present-day Route 16 until it ended at US 1 in Everett. Then, in 1931, an interchange in Revere was built over Route 107. In 1933, another, disconnected portion of Route 1A appeared between Attleboro and the Rhode Island state line. In 1934, two changes were made to the route. In Revere, the route was realigned to turn west smoothly. Between Boston and North Attleborough, a huge portion of Route 11 and all of Route 150 were replaced by Route 1A. The new portion soon got truncated to Dedham in 1936.It then got truncated even further to end at US 1/Route 128.