Massachusetts Route 40

Route 40
Route 40 highlighted in red
Route information
Maintained by MassDOT
Length	10.46 mi[1] (16.83 km)
Existed	late 1940s–present
Major junctions
West end	Route 119 / Route 225 in Groton
Major intersections	US 3 in Chelmsford
East end	Route 3A in Chelmsford
Location
Country	United States
State	Massachusetts
Counties	Middlesex
Highway system
Massachusetts State Highway System Interstate US State
← Route 39 → Route 41

Route 40 is a 10.46-mile-long (16.83 km) east–west state route located in northeastern Massachusetts, entirely within Middlesex County. The short highway connects Groton and Chelmsford. 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 has an interchange with Route 40, at exit 33.