U.S. Route 1 in Massachusetts

U.S. Route 1 (US 1) is a major north–south U.S. Route that runs from Key West, Florida, to Fort Kent, Maine. In the state of Massachusetts, it travels through Essex, Middlesex, Suffolk, Norfolk, and Bristol counties. The portion of US 1 south of Boston is also known as the Boston–Providence Turnpike, Washington Street, or the Norfolk and Bristol Turnpike, and portions north of Boston are known as the Northeast Expressway and the Newburyport Turnpike.

From the south, US 1 enters Massachusetts from Rhode Island, immediately entering the city of Attleboro. It closely parallels Interstate 95 (I-95) as it goes through the towns of North Attleborough, Plainville, Wrentham, Foxborough (where Gillette Stadium is located), Walpole, Sharon, Norwood, and Westwood. US 1 then has a wrong-way concurrency with I-95 up to the interchange that is the southern terminus of I-93. US 1 then travels concurrently with I-93 from Canton through Downtown Boston; Route 3 joins the concurrency in Braintree. In Downtown Boston, Route 1A and Route 3 separate from US 1 to head toward Logan International Airport and Cambridge respectively, and I-93 and US 1 separate just after passing through the O'Neill Tunnel and crossing the Leonard P. Zakim Bunker Hill Memorial Bridge. US 1 continues north, crossing the Tobin Bridge as the Northeast Expressway and traveling through Chelsea, Revere, and Malden, then as a four- to six-lane expressway through Saugus, Lynnfield, and Peabody.

The route through Saugus was once known for its abundance of kitschy roadside commercial architecture. Those that still exist as of 2023 include the 68-foot (21 m) neon cactus originally erected for the Hilltop Steak House, the tiki-styled Kowloon Restaurant, the Prince Restaurant's "Leaning Tower of Pizza", and a large orange dinosaur statue that was once part of a miniature golf course. Former structures along Route 1 included restaurants built in the shapes of a ship and a Chinese palace.

From Peabody, US 1 again closely parallels I-95 going through the towns of Danvers, Topsfield, Ipswich, Rowley, Newbury, and Newburyport. In Newburyport, US 1 has a mile-long (1.6 km) freeway segment that bypasses downtown and the waterfront areas; Route 1A joins the freeway shortly before it crosses the Merrimack River, entering Salisbury and becoming a surface arterial again. Three miles (4.8 km) later, it enters the state of New Hampshire.

Route 1A runs alongside US 1 in four parts of the state.

US 1 in Massachusetts was constructed in sections throughout the 1930s partly by widening existing roads and also by constructing new right of ways to bypass more congested areas. Originally, most of the highway was two or three lanes in each direction, with numerous widening and improvements made over the years.

Most of US 1 consists of two former turnpike roads—the Norfolk and Bristol Turnpike and the Newburyport Turnpike. The older roads that these turnpikes were meant to bypass are now mostly Route 1A.

The Newburyport Turnpike opened on February 11, 1805, and was constructed by a private company at a cost of $500,000 (equivalent to $10.5 million in 2024). The turnpike was used by stagecoaches and mail carriers for decades, but toll collection ceased in 1847 as parallel railroads attracted more use.