Route 85 is a 21.01-mile-long (33.81 km) north–south state highway in Massachusetts, United States. It passes through the heart of Boston's MetroWest region, through towns on the eastern edge of Worcester County and western edge of Middlesex County, crossing the border between the two counties four times. Throughout its entire distance, Route 85 runs parallel to I-495, never passing more than two miles from it.

Quick Facts Route 85, Route information ...

Route 85
Route 85 highlighted in red
Route information
Maintained by MassDOT
Length	21.01 mi[1] (33.81 km)
Major junctions
South end	Route 16 in Milford
Major intersections	I-495 in Milford Route 135 in Hopkinton Route 9 / Route 30 in Southborough US 20 in Marlborough Route 85 Connector in Hudson
North end	Route 117 in Bolton
Location
Country	United States
State	Massachusetts
Highway system
Massachusetts State Highway System Interstate US State
← I-84 → I-86

Close

Route 85 begins in the town of Milford at Route 16, just east of the downtown area. It passes east of Milford Pond before having a junction with I-495 at Exit 20. From there, Route 85 heads northward into Hopkinton, passing the eastern side of Echo Lake. It intersects Route 135 at the center of town, less than a quarter mile west of the starting line of the Boston Marathon. It then passes through Hopkinton State Forest and past the Hopkinton Reservoir before entering the town of Southborough.

In Southborough, Route 85 crosses under I-90 (the Mass Pike) without junction; the nearest exit is in neighboring Framingham. It then meets Route 9, the second of the four major east-west routes out of Boston, in an elevated four-way interchange. It then crosses the Sudbury Reservoir before meeting Route 30 at the center of town. From there, Route 85 continues northward into Marlborough, meeting U.S. Route 20 in the downtown area. It then passes the far western edge of the Fort Meadow Reservoir before crossing into Hudson.

Shortly after entering Hudson, Route 85 meets the Route 85 Connector, which provides access to I-290 and I-495. From there Route 85 heads north, crossing the Assabet River before meeting Route 62, passing concurrently with that route through Wood Square before Route 85 continues northward. After passing into Bolton, the route passes between Little Pond and West Pond before ending at Route 117, less than a half mile east of I-495's exit 27.