east of Cook Street. NY&NE successor New York, New Haven and Hartford Railroad began routing most NY&NE trains over a new cutoff from to in 1906. The remaining grade crossings on the line were eliminated in 1905–07. Passenger service on the 1852-built line south of Cook Street ended in 1927. (A portion in Needham remains in use as part of the Needham Line). Passenger service on the line ended on May 31, 1958. Conversion to light rail Conversion of the Highland branch to a third-rail rapid transit line was proposed in 1913. That proposal called for trains to reach downtown Boston using the then-under-construction Boylston Street subway, which was built for streetcars but sized for rapid transit conversion, with a connection near Governor Square. In May 1924, the state legislature directed the Metropolitan District Commission to plan an expanded rapid transit system in Boston. The plan, released in 1926, called for the existing streetcar subway to be converted into two rapid transit lines. A number of potential future extensions were listed; among them was conversion of most of the Highland branch to rapid transit, linking with a Huntington Avenue subway at Brookline Village. In 1943, the state legislature appointed a commission headed by Arthur W. Coolidge to plan for the future of transit in the Boston region. In 1945, a preliminary report from the Coolidge Commission recommended nine suburban rapid transit extensions – most similar to the 1926 plan – along existing railroad lines. The Highland branch was to be converted to a rapid transit line, using low-floor trains that could operate in the existing streetcar subway. A branch would use the former Charles River Branch Railroad route to . Separately, two tracks of the B&A mainline would be converted to rapid transit, also terminating at Riverside. The final report in 1947 did not recommend any changes to the Highland branch route, though it recommended extending the Needham Junction spur to . Cost was estimated at $1.544 million in 1941 dollars (equivalent to $ million in ) for the Riverside route, plus $424,000 (equivalent to $ million in ) for the Needham spur. On June 20, 1957, the state legislature authorized the Metropolitan Transit Authority (MTA) to acquire the Highland branch and convert it to rapid transit at a cost not to exceed $9.2 million (equivalent to $ million in ). The project was approved by the MTA Advisory Board