Lebanon Mountain Road, West Housatonic Street, South Street, Lee Road, Laurel Street, West Center Street, Main Street, Park Street, Housatonic Street, Water Street, Chapel Street, Cape Street, Jacobs Ladder Road, Chester Road, West Main Street, Huntington Road, Russell Road, Franklin Street, Elm Street, Springfield Road, Westfield Street, Park Avenue, Park Street, North End Bridge, West Street, Plainfield Street, Springfield Expressway, Page Boulevard, Pasco Road, Boston Road, Wilbraham Street, North Main Street, Thorndike Street, Palmer Road, Sturbridge Road, Charlton Road, Worcester Road, Southbridge Road, Southbridge Street, Washington Street, Southwest Cutoff, Hartford Turnpike, Boston Post Road West, Lakeside Avenue, Granger Boulevard, East Main Street, Boston Post Road East, Boston Post Road, Weston Street, North Beacon Street, Brighton Avenue, Commonwealth Avenue

Direction:

East/West

Western Terminus:

New York-Massachusetts state line

Eastern Terminus:

Beacon Street (MA 2) and Commonwealth Avenue (MA 2) in Boston

Distance:

153.41 miles

Counties:

Berkshire, Hampden, Hampshire, Worcester, Middlesex, Suffolk

Signed:

Yes

US 20 is a major east/west route crossing the country from Newport, Oregon, to Boston, Massachusetts. It is the longest numbered route in the United States. US 20 enters Massachusetts from New York and runs east to Pittsfield, where it joins US 7. The two routes run south together to Lenox, where they split. US 20 continues southeast to Lee, where there is an interchange with the Massachusetts Turnpike (I-90).

US 20 runs near the Massachusetts Turnpike (I-90) for most of the remainder of its length. In Springfield, it crosses the Connecticut River on the North End Bridge and then follows the Springfield Expressway (I-291) for most of its length, splitting off one exit before the end. US 20 continues east to Boston, where it becomes Commonwealth Avenue, a large divided roadway with a park in the median. US 20 ends at the intersection where MA 2 turns from Beacon Street onto Commonwealth Avenue.