District of Columbia Code Division VIII. General Laws. § 50-202. Official use.

All passenger motor vehicles and watercraft owned by the District of Columbia shall be operated and utilized in conformity with 31 U.S.C. §§ 1343(a) to (d), 1344, and 1349(b), and shall be under the direction and control of the Mayor of the District of Columbia. The Mayor is authorized to alter or change the assignment or direct the alteration or interchangeable use of any passenger motor vehicles or watercraft by officers and employees of the District of Columbia except as otherwise provided in such sections. Limitations on the official use of passenger motor vehicles, as set out in such sections, shall not apply to the Mayor or, with the approval of the Mayor, to officers and employees of the District government the character of whose duties make such transportation necessary.