The construction of this line, in conjunction with the construction of the Lexington Avenue Line, would change the operations of the IRT system. Instead of having trains go via Broadway, turning onto 42nd Street, before finally turning onto Park Avenue, there would be two trunk lines connected by the 42nd Street Shuttle. The system would be changed from looking like a "Z" system on a map to an "H" system. One trunk would run via the new Lexington Avenue Line down Park Avenue, and the other trunk would run via the new Seventh Avenue Line up Broadway. In order for the line to continue down Varick Street and West Broadway, these streets needed to be widened, and two new streets were built, the Seventh Avenue Extension and the Varick Street Extension. It was predicted that the subway extension would lead to the growth of the Lower West Side, and to neighborhoods such as Chelsea and Greenwich Village.