South Bay Junction to Braintree/South Braintree

The Out-of-Service track leaves the Dorchester Branch on the east side at South Bay Junction (MP 227.0), heading south, and turns south-southeast, past Fields Corner, Neponset, where an erstwhile line to Mattapan once left to the southwest, a bridge over a river, Atlantic, where the route splits into one heading south through East Milton and one continuing south-southwest past Wollaston, turning south past Quincy, becoming the West Quincy Industrial Track, and coming back together with the East Milton liner at Braintree (CR MP 0.0), where the Greenbush Line (the Weymouth Industrial Track) turns east, with the "main line" continuing south, past Ivory (CR MP 1.3), south end of the Conrail Braintree Yard, to South Braintree, where the Plymouth Line (Bay Colony Railroad Plymouth Main Line) turns east-southeast and the Middleboro Line (Conrail Braintree Secondary) continues south.