Route 40 is a 10.5-mile east–west state route located in northeastern Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

, entirely within Middlesex County

Middlesex County, Massachusetts

-National protected areas:* Assabet River National Wildlife Refuge* Great Meadows National Wildlife Refuge* Longfellow National Historic Site* Lowell National Historical Park* Minute Man National Historical Park* Oxbow National Wildlife Refuge...

. The short highway connects Groton

Groton, Massachusetts

Groton is a town located in northwestern Middlesex County, Massachusetts. The population was 10,646 at the 2010 census. It is home to two noted prep schools: Groton School, founded in 1884, and Lawrence Academy at Groton, founded in 1793. The historic town hosts the National Shepley Hill Horse...

 and Chelmsford

Chelmsford, Massachusetts

Chelmsford is a suburban town in Middlesex County, Massachusetts in the Greater Boston area. As of the 2010 United States Census, the town's population was 33,802. The Census Bureau's 2008 population estimate for the town was 34,409, ranking it 14th in population among the 54 municipalities in...

. Its western end is at an intersection with Massachusetts Route 119 and Massachusetts Route 225 in Groton, and its eastern end is at Route 3A in North Chelmsford. The route has existed since the late 1940s.

U.S. Route 3

U.S. Route 3

U.S. Route 3 is a north–south United States highway that runs from its southern terminus in Cambridge, Massachusetts through New Hampshire to its terminus near Third Connecticut Lake at the Canadian border, where the road continues north as Quebec Route 257.In New Hampshire parts of US 3 are...

 has an interchange with Route 40, at Exit 33.

Route description

Route 40 begins in the west near the center of Groton at an intersection with Main Street (Routes 119 and 225). The highway proceeds eastward out of the downtown area, passing through the northern part of the town of Westford. Most of the route winds through rather densely wooded areas, with several ponds located alongside or near the highway. The road continues into North Chelmsford, where it interchanges with U.S. Route 3 at Exit 33. Route 40 continues another mile eastward, emerging from the woods before ending at an intersection with Route 3A in the center of North Chelmsford at Vinal Square, located just west of the Merrimack River

Merrimack River

The Merrimack River is a river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Atlantic Ocean at Newburyport...

.

Junction list

County	Location	Mile	Roads intersected	Notes
Middlesex Middlesex County, Massachusetts -National protected areas:* Assabet River National Wildlife Refuge* Great Meadows National Wildlife Refuge* Longfellow National Historic Site* Lowell National Historical Park* Minute Man National Historical Park* Oxbow National Wildlife Refuge...	Groton Groton, Massachusetts Groton is a town located in northwestern Middlesex County, Massachusetts. The population was 10,646 at the 2010 census. It is home to two noted prep schools: Groton School, founded in 1884, and Lawrence Academy at Groton, founded in 1793. The historic town hosts the National Shepley Hill Horse...	0.00	Route 119 Route 225	Western terminus of Route 40. To Route 111, via Route 119/225 West.
	North Chelmsford Chelmsford, Massachusetts Chelmsford is a suburban town in Middlesex County, Massachusetts in the Greater Boston area. As of the 2010 United States Census, the town's population was 33,802. The Census Bureau's 2008 population estimate for the town was 34,409, ranking it 14th in population among the 54 municipalities in...	9.1	U.S. Route 3 U.S. Route 3 U.S. Route 3 is a north–south United States highway that runs from its southern terminus in Cambridge, Massachusetts through New Hampshire to its terminus near Third Connecticut Lake at the Canadian border, where the road continues north as Quebec Route 257.In New Hampshire parts of US 3 are...	US-3 Exit 33.
		10.46	Route 3A Massachusetts Route 3A Route 3A is a 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....	Eastern terminus of Route 40. To Route 4, via Route 3A South.