The route then travels for 55 miles in metro-south Boston and in suburbs in Southeastern Massachusetts. The route travels past the Blue Hills on
MA 138 in
Milton and continues into
Canton, then turns down Randolph St. which becomes Canton St. in
Randolph. It is a concurrent with
MA 28 into
Avon, where it exits onto E. High St. heading towards Boundary St. and eventually N. Quincy St. in
Brockton. It intersects
MA 123 and
MA 27 before continuing straight to the access road for Massasoit Community College. At the end of the access road, it turns left onto Thatcher St and continues as Elm St. in
East Bridgewater. It then turns left onto North Central Street and crosses
MA 18, becoming Central Street as it continues toward Chestnut St., Bridge St., and Crescent St. It then follows down Washington St. until its next turn onto Pond St. which leads into
Halifax. It then turns onto Elm St. and continues to Pine St. where it turns east on
MA 106 for a short while and then turns onto Carver St. It eventually turns into South St. then onto Franklin St., continuing into
Plympton. It travels down Center St. towards
MA 58 where it is joined going south into the town center before turning onto Mayflower St. It continues on Colchester Rd. and Brook St. before becoming Elm St. in
Kingston where it joins
MA 80 for four miles heading down into
Plymouth. It turns onto Carver St. and continues past the big intersection (use the rightmost lane) before turning onto Summer St. toward downtown Plymouth. It turns onto
MA 3A for half a mile before exiting onto South St. and eventually becoming Long Pond Rd. It passes under
MA 3 and continues down toward the Myles Standish State Forest and Plymouth South High School before merging left onto Hedges Pond Rd., where the route will re-meet Route 3A and continue straight onto State Rd. towards the Sagamore Bridge in
Bourne. Riders must use the
Sagamore Bridge to cross the
Cape Cod Canal, and they must walk their bicycles across the bridge. Access to the bridge is available by going straight on Canal Street just past the Sagamore Park and Ride lot on the right. ==Cape Cod==