 In 1929 , the Board of Transportation of the City of New York tentatively approved the expansion , which included a Second Avenue Line with a projected construction cost of $ 98 @,@ 900 @,@ 000 ( equivalent to $ 1 @,@ 351 @,@ 000 @,@ 000 in 2015 ) , not counting land acquisition . From north to south , the 1929 plan included four tracks from the Harlem River ( where it would continue north as a Bronx trunk line with several branches ) to 125th Street , six tracks from 125th Street to a link with the Sixth Avenue Line at 61st Street , four tracks from 61st Street to Chambers Street , and two tracks from Chambers Street to Pine Street . The plan was soon modified with the addition of another Bronx branch , as well as an extension of the subway to Water and Wall Streets . At the time , it was supposed to be completed between 1938 and 1941 . In anticipation of the line 's opening , real estate prices along the proposed route rose by an average of 50 % . 
