The following words and terms, when used in this subchapter, shall have the following meanings, unless the context clearly indicates otherwise.
  (1) Commission--The Texas Transportation Commission.
  (2) Department--The Texas Department of Transportation.
  (3) District--A geographical area managed by a district engineer, in which the department conducts its primary work activities.
  (4) Environmental speed limit--A speed limit created by the commission at the request of the Texas Commission on Environmental Quality for the purposes of meeting federal air quality standards.
  (5) Farm-to-Market (FM) or Ranch-to-Market (RM) road--A road shown in the records of the commission to be a farm-to-market or ranch-to-market road.
  (6) May--A permissive condition.
  (7) Regional Mobility Authority--An authority created under Transportation Code, Chapters 361 or 370, at the request of one or more counties and authorized by the commission for the purpose of constructing, maintaining, and operating transportation projects.
  (8) Regional Tollway Authority--An authority created under Transportation Code, Chapter 366, consisting of two or more counties for the purpose of acquisition, design, financing, construction, operation, and maintenance of a turnpike project or system.
  (9) Shall--A mandatory condition.
  (10) Should--Advisable but not mandatory; however, any reason for not following the instruction shall be supported by sound engineering judgment.
  (11) TCEQ--The Texas Commission on Environmental Quality which is the state air pollution control agency and is the principal authority in the state of Texas on matters relating to the quality of the state's air resources.
  (12) Texas Manual on Uniform Traffic Control Devices (TMUTCD)--The manual, and any revisions, adopted by the commission as required under Transportation Code, §544.001.
  (13) Trial runs--A drive through the speed zoned section of roadway at the chosen speeds to determine if the speeds are appropriate for the area.

Source Note: The provisions of this §25.20 adopted to be effective December 9, 2004, 29 TexReg 11389; amended to be effective October 16, 2008, 33 TexReg 8557