The divided highway runs from Atlantic Avenue in Cypress Hills, Brooklyn to Hook Creek Boulevard in Rosedale, Queens at the Nassau County border.

East of Brookville Boulevard, South Conduit Avenue parallels the Montauk Branch of the Long Island Rail Road (LIRR) and continues as Sunrise Highway in Valley Stream.

[1] Conduit Avenue is designated as New York State Route 27 between Linden Boulevard and the Nassau County border and accommodates car, bus and truck traffic.

[5] The western segment of the highway, between Atlantic Avenue and Cross Bay Boulevard, was originally slated to be the eastern part of a planned, but never built, Bushwick Expressway.

[8] The original Brooklyn Waterworks brick conduit stretched from Long Island to the Ridgewood Pumping Station, now the site of City Line Park, in East New York.

[4][11] The aqueduct was located on the north side of what is now Conduit Avenue, and was built on a right-of-way that had not been developed at the time.

[2] By 1928, the entire stretch from Brooklyn to Amityville was officially named the Sunrise Highway, following efforts by the Long Island Chamber of Commerce.

[18][16][23] The original 1931 plans, known as the Southern State Parkway extension, called for an arterial road adjacent to the existing narrow Sunrise Highway.

[16][23] As early as July 1934, land was acquired via eminent domain to widen Conduit Boulevard and build the new parkway.

[12][23][26][27][28] In justifying the conversion of the Conduit route into part of the Belt system, NYC Parks commissioner Robert Moses cited the "approximately 10,000,000 cars" traveling the route on an annual basis, and the need for a highway link between Brooklyn and Long Island to create "the ultimate circumferential boulevard.

[7] An alternate routing proposed in the 1960s by the Triborough Bridge and Tunnel Authority (TBTA) would have traveled slightly farther north, connecting to the Long Island Expressway (I-495) in western Queens.

[44] In 2000, NYC Parks published a report in which it proposed constructing a bikeway and horse trail within the large grassy median of Conduit Boulevard.