(a) Levels of priority. (1) There are two levels of priority established by the Transportation Priorities and Allocations System regulations, identified by the rating symbols “DO” and “DX”.

(2) All DO-rated orders have equal priority with each other and take precedence over unrated orders. All DX-rated orders have equal priority with each other and take precedence over DO-rated orders and unrated orders. (For resolution of conflicts among rated orders of equal priority, see § 33.34(c).)

(3) In addition, a Directive regarding priority treatment for a given item issued by the resource agency with priorities jurisdiction for that item takes precedence over any DX-rated order, DO-rated order, or unrated order, as stipulated in the Directive. (For a full discussion of Directives, see § 33.62.)

(b) Program identification symbols. Program identification symbols indicate which approved program is being supported by a rated order. DOT will use the letter “T” followed by a number for all transportation-related approved programs. Programs may be approved under the procedures of Executive Order 13603 at any time. Program identification symbols, in themselves, do not connote any priority.

(c) Priority ratings. A priority rating consists of the rating symbol—DO and DX—and the program identification symbol, such as DO-T1 or DX-T1 for a priority rating under TPAS.