The New York City Department of Plant and Structures was an operator of transit in New York City. In September 1919, Mayor John Francis Hylan charged the department with organizing private entrepreneurs to operate "emergency" buses to replace four abandoned storage battery streetcar lines: the Madison Street Line, Spring and Delancey Streets Line, Avenue C Line, and Sixth Avenue Ferry Line. The system gradually grew, taking over various lines including the Brooklyn and North River Line (trolleys) and Queens Bus Lines (buses), and the DP&S also began operating trolleys in Staten Island to replace the Staten Island Midland Railway's system. Eventually all of these routes were transferred to private management.
Among the DP&S's acquisitions was the Bridge Operating Company, which ran the Williamsburg Bridge Local trolley, in 1921. Unlike the other lines, this one remained city-operated, and was replaced by the B39 bus route on December 5, 1948, by then transferred to the New York City Board of Transportation.
|| Defunct New York City Transit Operators
| Steam railroads later converted to rapid transit systems
|| Brooklyn and Brighton Beach Railroad Brooklyn, Bath and Coney Island Rail Road Brooklyn, Bath and Coney Island Railroad Brooklyn, Bath and West End Railroad Brooklyn, Flatbush and Coney Island Railway Coney Island Elevated Railway Greenwood and Coney Island Railroad Marine Railway New York and Coney Island Railroad New York and Manhattan Beach Railway New York and Sea Beach Railroad New York and Sea Beach Railway New York, Brooklyn and Manhattan Beach Railroad Prospect Park and Coney Island Railroad Sea Beach Railway Sea View Railroad
| Rapid transit systems
|| Brooklyn-Manhattan Transit Corporation Brooklyn Rapid Transit Company Brooklyn Union Elevated Railroad Interborough Rapid Transit Company Kings County Elevated Railway
| Streetcar systems
Avenue C Railroad Company Belt Line Railway Bleecker Street and Fulton Ferry Railroad Broadway and Seventh Avenue Railroad Broadway Surface Railroad Broadway Railway Company Brooklyn and North River Railroad Brooklyn & Queens Transit Corporation Brooklyn Central and Jamaica Railroad Brooklyn City Rail Road Brooklyn Crosstown Railroad Brooklyn, Queens County and Suburban Railroad Bush Terminal Railroad Bushwick Railroad Calvary Cemetery, Greenpoint and Brooklyn Railroad Central Crosstown Railroad Company
Central Park, North and East River Railroad Chambers Street and Grand Street Ferry Railroad Christopher and Tenth Street Railroad Company Columbus and Ninth Avenue Railroad Coney Island and Brooklyn Rail Road Coney Island, Fort Hamilton and Brooklyn Railroad Dry Dock, East Broadway and Battery Railroad Eighth Avenue Railroad Company Flushing and College Point Electric Railway Fort George and Eleventh Avenue Railroad Forty-Second Street and Grand Street Ferry Railroad Company Fourth Avenue Street Railway Fulton Street Railroad Grand Street and Newtown Rail Road Greenpoint and Lorimer Street Railroad Houston, West Street and Pavonia Ferry Railroad Interurban Street Railway Jamaica Central Railways Company Kings County Electric Railway Lexington Avenue and Pavonia Ferry Railroad Long Island City and Calvary Cemetery Railroad Long Island City and Maspeth Railroad Long Island City and Newtown Railway Long Island Electric Railway Manhattan and Queens Traction Company Manhattan Bridge Three Cent Line Marine Railway Maspeth Avenue and Toll Bridge Company Maspeth Railroad and Bridge Company Metropolitan Crosstown Railway Metropolitan Street Railroad Metropolitan Street Railway Nassau Electric Railroad Newtown Railway New York City Department of Plant and Structures New Williamsburgh and Flatbush Railroad New York and Harlem Railroad Company New York and North Shore Traction Company New York and Queens County Railway Company New York and Queens Transit Corporation New York City Railway Company New York Railways Company Ninth Avenue Railroad Company Park Avenue Railroad Port Richmond & Prohibition Park Electric Railroad Queensboro Bridge Railway Company Richmond County Railroad Richmond Light & Railroad Company Richmond Railways Rikers Avenue and Sanford Point Railroad Second Avenue Railroad Sixth Avenue Railroad Company South Brooklyn Street Railroad South Ferry Railroad Company Staten Island Electric Railroad Staten Island Midland Railroad Staten Island Midland Railway Staten Island Traction Company Steinway and Hunters Point Railroad Steinway Railway Corporation Third Avenue Railroad Third Avenue Railway Third Avenue Transit Corporation Thirty-fourth Street Crosstown Railway Twenty-eighth and Twenty-ninth Streets Crosstown Railroad Twenty-Third Street Railroad Company Union Railroad (Brooklyn) Union Railway Company of New York City Van Brunt Street and Erie Basin Rail Road
| Bus systems
|| Affiliated Bus Transit Corporation Argus Line Transportation Corporation Avenue B & East Broadway Transit Company B&L Transportation Bilow Bus Line Brooklyn Bus Corporation Command Bus Company Comprehensive Omnibus Corporation Concourse Bus Lines Courier Bus Company Eastern Parkway, Brownsville and East New York Transit Relief Association East Side Omnibus Corporation Fifth Avenue Coach Company Fifth Avenue Coach Lines, Incorporated Flushing Heights Bus Company General Omnibus Corporation Greater Cities Bus Lines Green Bus Lines Hamilton Bus Company Independent Buses Isle Transportation Co. Jamaica Bus Line Jamaica Buses Kings Coach Company Liberty Bus Transportation Liberty Lines Express Long Island Coach Company Madison Avenue Coach Company, Incorporated Manhattan & Queens Bus Corporation Midland Coach Corporation Municipal Motorbus Company National City Bus Lines New York Bus Service New York City Department of Plant and Structures New York City Omnibus Corporation North Shore Bus Company Pioneer Bus Company Plum Beach Auto Stage Queens Auto Traction Queens Bus Corporation Queens Bus Lines Queens-Nassau Transit Lines Queens Surface Corporation Queens Transit Corporation Rauchwerger Bus Company Richmond Hill Bus Line Ruoff Brothers S&C Buses S&F Transportation Staten Island Coach Company Steinway Omnibus Corporation Steinway Transit Corporation Surface Transit, Incorporated Surface Transportation Corporation of New York Tompkins Bus Company Triangle Bus Company Triboro Coach Corporation Woodside-Astoria Transportation Company Z&M Coach Company