D.C. Mun. Regs. tit. 10-B, § 2711
2711.1 All cul-de-sac streets shall meet the following requirements:
(a) All requirements of §2709.2;
(b) Not be over six hundred feet (600 ft.) in length, unless topographical conditions render this provision impracticable; and
(c) Not be adverse to the public interest.
2711.2 All dead end streets shall be provided with a turning area at the end thereof with a minimum radius of sixty feet (60 ft.) and with building restriction lines ten feet (10 ft.) back of the property line.
SOURCE: Commissioners' Order 67-651(a), §3, effective May 16, 1967, 13 DCR 270 (June 19, 1967).