The 2000 (or Millennium) Edition of the MUTCD was published by the Federal Highway Administration in December of 2000. This replaced the 1988 edition, and served as the official edition of the MUTCD in the United States until the publication of the 2003 edition.
In the 1988 and previous editions, the MUTCD was written in a manner that mixed mandatory, recommended, and optional practice. This led to some ambiguity. Public agencies reported that in litigation, plaintiffs' counsel and experts would declare entire sections to be mandatory standard practice, even though the wording and phrasing (including the use of the words "should" and "may") indicated otherwise.
Standard, Guidance, Option, Support
During the development process for the 2000 edition, FHWA and NCUTCD rewrote the MUTCD's content to split it into Standard, Guidance, Option, and Support paragraphs within each section. Standard statements are considered mandatory practice, to be followed in every reasonable circumstance. Guidance statements are considered recommended practice, to be generally followed unless an engineering study or engineering study indicates an alternative is preferable. Option statements are optional or discretionary practices. Support statements provide additional information useful to practitioners.
Rulemaking and Public Comment
Adoption by the States
Notable Changes from the 1988 Edition
The 2000 MUTCD was published in a book using 8 1/2" x 11" US letter size paper, whereas earlier editions were smaller "handbook"-sized volumes. The number of pages also increased substantially.
The 2003 Edition of the MUTCD revised several of the sections that were controversial in the 2000 edition.