Prior to 1982, the Route 25 designation was given to that segment of what is now I-495 from Route 24 in Raynham to the interchange with I-195 in Wareham. Upon completion of the I-495 segment between Route 24 and I-95, that portion of the existing freeway was redesignated as I-495 in various stages during the 1970s and 1980s, eventually reducing Route 25 to a segment that continued eastward from I-495 to the modern location of Exit 2 in Downtown Wareham. Construction of an eastern continuation of Route 25 to the Bourne Bridge was delayed for nearly three decades due to property disputes and environmental concerns, but the final segment opened in 1987. The freeway was originally planned to continue over the Bourne Bridge into Cape Cod as part of the Southside Connector, but this plan was abandoned by the Massachusetts Highway Department (MassHighway) in the late 1970s.