D.C. Code § 9-1201.11
It shall be lawful for the Baltimore and Potomac Railroad Company to extend and construct, from time to time, branch tracks or sidings from the lines of railroad authorized hereunder, into any lot or lots adjacent to any street or avenue along which said lines of railroad are located, upon the application of the owner or owners of such lot or lots, to enable such owners to use their property for the purpose of coal, wood, or lumber yards, manufactories, warehouses, and other business enterprises; provided, however, that no grade crossing of any street or avenue within the City of Washington shall be thereby created, but such connecting tracks shall be carried across such street or avenue in such manner as not to obstruct the free use thereof, and the plans of such connecting tracks shall in every case be first filed with and approved by the Mayor of the District of Columbia.
D.C. Code § 9-1201.11