The B48 bus route constitutes a public transit line in Brooklyn, New York City, running along Lorimer Street, Franklin Avenue, and Classon Avenue between Flatbush and Greenpoint.

From there, buses run along the length of Lorimer Street until Nassau Avenue.

[11][12] On October 28, 1945, Lorimer Street cars were extended on both their northern and southern ends to replace discontinued service on the Franklin Avenue Line and on the Nassau Avenue Line.

[15] The route now runs northbound on Classon Avenue rather than Franklin Avenue; the south end was truncated back to the east side of Prospect Park.

[citation needed] On December 1, 2022, the Metropolitan Transportation Authority released a draft redesign of the Brooklyn bus network.