eastbound Route 139 begins in
Stoughton Square at the southern junction of the
Route 27 and
138 concurrency. The highway heads northeast until the junction with
Route 24, at which point the highway heads almost due east. After the brief concurrency with
Route 28 in Randolph, the highway heads in a generally east-southeasterly direction through
Holbrook, the extreme southwest corner of
Weymouth, the North Abington section of
Abington,
Rockland,
Hanover, the northern edge of
Pembroke, and
Marshfield. Once the highway reaches the shoreline in Marshfield, it turns in a south-southeasterly direction, passing through Fieldston,
Ocean Bluff and Brant Rock, proceeding until just north of Brant Rock's
esplanade. But then the highway heads west, while still signed east, for the last , passing through
Cedar Crest before ending at
Route 14 in
Duxbury. ==Major intersections==