ADDITIONAL RELIEF FOR THE SOUTH SHORE: In its 1968 Recommended Highway and Transit Plan, the Massachusetts Department of Public Works (MassDPW) advocated the construction of a new six-lane expressway to supplement MA 3 (Pilgrims Highway), and provide relief for the existing MA 3A - which the expressway was to parallel - through the South Shore.
Beginning at the "Braintree Split" interchange between the Southeast Expressway (I-93, US 1 and MA 3), Yankee Circumferential Highway (I-93, former MA 128) and Pilgrims Highway (MA 3), the Shawmut Trail Expressway was to extend east through Braintree, Weymouth and Hingham. A new bridge was to be constructed over the Fore River. Finally, near the eastern terminus of the expressway, a connection was to be provided with the Hingham Spur (MA 228). The proposed route was expected to carry anywhere from 65,000 to 100,000 vehicles per day (AADT).
In the following excerpt, the MassDPW stated its case for constructing the Shawmut Trail Expressway:
By 1990, some form of relief will have to be provided to the South Shore area. In addition to traffic engineering improvements, arterial improvements paralleling the Southeast Expressway, and reliance on transit, another alternative considered was the construction of arterials or the improvement of existing arterials to provide access from Weymouth and Hingham to MA 3 in a generally north-south direction. However, arterials would not be sufficiently attractive to draw significant amounts of traffic from other arterials.
The Shawmut Trail Expressway appears to be the most practical solution for facilitating vehicular movement along the South Shore. A connection with the Hingham Spur (MA 228) would also be desirable to preserve system continuity and offer partial relief to Pilgrims Highway (MA 3).
The expressway, while relieving MA 3A, Morissey Boulevard and the local street system, is not without its disadvantages. The additional load placed on the Southeast Expressway can only cause added congestion on the already heavily loaded facility. The discharge of up to 100,000 vehicles per day at the MA 3 / MA 128 interchange would necessitate special, costly ramp connections to avoid severe weaving problems.
Expanding the capacity of the Southeast Expressway and constructing the Shawmut Trail Expressway, with direct connections to the Southeast Expressway and MA 128, together with the rapid transit extension to Braintree and beyond, should contribute substantially toward solving one of the region's major transportation problems.
The 8.6-mile-long Shawmut Trail Expressway, which was estimated to cost $31 million, was in the long-range construction program for construction after 1975. However, even as it was announced, opposition had sprung up along the route of the expressway. By the early 1970's, the MassDPW quietly shelved plans for the expressway.