D.C. Mun. Regs. tit. 31, § 1402
1402
SEDAN CLASS RATES AND CHARGES
1402.1
Passenger rates and charges for sedan class service shall:
(a) Be based on time and distance rates as set by the DDS except for a set fare for a route approved by the Office order for a well-traveled route, including a trip to an airport or to an event;
(b) Be disclosed to the passenger in a statement of the DDS' fare calculation method;
(c) Be used to calculate an estimated fare that shall be offered to the passenger prior to the acceptance of service, which shall state whether demand pricing applies, and, if so, the effect of such pricing on the estimate;
(d) Be consistent with the DDS statement of its fare calculation method posted on its website pursuant to Chapter 16;
(e) Not exceed the estimated fare by more than twenty percent (20%) or twenty five dollars ($25), whichever is less, unless the excess is due to delays or stopovers en route at the direction of the passenger, or other factors beyond the operator's control, such as traffic, accidents, or construction; and
(f) Not include a gratuity that does not meet the definition of a "gratuity".
SOURCE: Final Rulemaking published at 60 DCR 12410 (August 30, 2013).