The D Subway Line is a rapid transit line in the New York City Subway system, identified by its dark blue color on maps. It runs from Coney Island-Stillwell Avenue in Brooklyn to Fordham Road in the Bronx, covering a distance of approximately 24 miles. The line operates local and express services, making it a vital transportation option for commuters and residents. The D Line serves several key neighborhoods, including Brighton Beach, Park Slope, and Kingsbridge. It connects with multiple other subway lines, enhancing accessibility across the city. The line is known for its frequent service and is an essential part of the city's public transit network.