Note: the following content was written based on the 10th edition of the MUTCD. It will be updated soon to reflect the 11th edition of the MUTCD, which became the current edition in December 2023.
The size, structure, and content of the Manual on Uniform Traffic Control Devices (MUTCD) can make it a challenging document to use. The MUTCD is not intended to be a checklist type of document that can be used by any individual. Instead, proper use of the MUTCD necessitates an understanding of traffic engineering principles and other factors that can impact traffic control device (TCD) decisions on an individual and agency-wide basis. There is no “MUTCD for Dummies” type of document that explains how to use the MUTCD. Below is some guidance to help use the MUTCD in a more effective manner.
The MUTCD has an introduction, nine parts, and two appendices.
- The Introduction and Part 1 provide general information about TCDs. Of particular significance is the definitions in Part 1. These definitions establish a legal basis for the use of TCDs. An MUTCD user should understand how the applicable definitions affect the use of a specific TCD.
- Parts 2 (Signs), 3 (Markings), and 4 (Signals) establish TCD criteria for the three basic types of TCDs.
- Parts 5 (Low Volume Roads), 6 (Temporary Traffic Control), 7 (School Areas), 8 (Railroad and Light Rail Transit Grade Crossings), and 9 (Bicycle Facilities) establish TCDs for the applicable specialized application. These parts on specialized application may reference the basic types of TCDs (Parts 2-4) and/or may introduce new TCDs that are specific to those specialized applications.
- The two appendices address TCD use related to Congressional legislation and the conversion to metric dimensions for TCD applications.
The MUTCD divides content into parts, chapters, sections, and paragraphs.
This provides the ability to reference a specific paragraph by its location within a part, chapter, section, and paragraph. For example, the requirement that there is no border in a Chevron sign is found in Part 2 (Signs), Chapter C (Warning Signs), Section 09 (Chevron Alignment Sign), and paragraph 03. As such, reference to this content is shown as 2C.09p03.
The stovepipe organization of the MUTCD means that the appropriate use of TCDs at a specific location involves content from sections in multiple parts of the MUTCD.
For example, the selection of TCDs for a signalized intersection with bicycle lanes located near a grade crossing would potentially involve using content from Parts 1, 2, 3, 4, 8, and 9. A user needs to know where to access the appropriate content in each of these parts.
The content in the MUTCD is divided into three levels of mandate plus background information. Proper use necessitates a clear understanding of the levels of mandate and the potential impacts on the use of devices.
- Standard: Standards establish a required, mandatory, or prohibited practice. Standard statements use the verb “shall” and appear in bold type in the MUTCD. Standard statements are intended to provide uniformity in TCD use across the country. Although standard statements are intended to establish a requirement, the MUTCD states that it is not a substitute for engineering judgment (1A.09p03). As such, there may be limited situations where a standard may not be the most appropriate application of TCD criteria. Any deviation from a Standard statement should be documented. There are 975 Standard headings in the 2009 MUTCD and the word “shall” appears 3,046 times in the 2009 MUTCD.
- Guidance: Guidance statements establish a recommended practice. Guidance statements use the verb “should” and appear in italic type in the MUTCD. These recommendations are not requirements, although some agencies implement recommendations in the same manner that they do requirements. Guidance statements are intended to provide consistency in TCD use across the country. Recommendations could be considered as best practices. As such, any deviation from a recommendation should be documented. There are 904 Guidance headings in the 2009 MUTCD and the word “should” appears 2,625 times in the 2009 MUTCD.
- Option: Option statements indicate a permissive practice with no requirement or recommendation. Option statements use the verb “may” and appear in normal type in the MUTCD. A practitioner has a choice on whether to implement an optional practice. In some cases, an Option statement may indicate exceptions or modifications to a Standard or Guidance statement. Option statements are intended to provide additional flexibility in the use of TCDs. There are 896 Option headings in the 2009 MUTCD and the word “may” appears 1,788 times in the 2009 MUTCD.
- Support: Support statements provide the practitioner with background information. Support statements do not carry any degree of mandate and do not use the words “shall,” “should,” or “may.” As with Option statements, Support statements appear in normal type. There are 716 Support headings in the 2009 MUTCD.
The MUTCD may indicate either “engineering judgment” or an “engineering study” is the basis for the application (selection) of a specific TCD.
These two terms are defined in the MUTCD in Section 1A.13. One of the key differences between the use of engineering judgment and an engineering study is that an engineering study must be documented.
The MUTCD has grown gradually and incrementally over a period of more than 85 years.
Much of the content in early editions of the MUTCD were based on the best judgment of those responsible for the MUTCD. In more recent editions, there has been an emphasis on basing MUTCD content on the results of research and/or agency experiments. The Federal Register notices for the Notice of Proposed Amendments and/or Final Rule typically includes information that identifies the basis for selected MUTCD content. Practitioners should not use the MUTCD as the sole reason for not implementing a suggestion from elected officials or the public. The practitioner should not say “The MUTCD won’t let us do that” unless the practitioner then expands upon the statement to explain why the MUTCD does not allow that practice. If a practitioner does not know why the MUTCD prohibits a practice, they should consult with more experienced MUTCD users to find out.
Each state has a state law that establishes the version of the national MUTCD that is applicable in that state.
A state has three options for adopting the national MUTCD:
- Adopt the national MUTCD in its entirety,
- Adopt the national MUTCD and a state supplement that provides additional criteria, or
- Adopt a state MUTCD.
The CFR requires that state supplements and manuals be in substantial conformance with the national MUTCD. Once the federal government revises the MUTCD through the rulemaking process, states have two years to implement state updates through one of the three options for adopting the MUTCD. For those states that adopt the national MUTCD as their state MUTCD, some state laws immediately adopt the national MUTCD when it becomes effective. Other states must take formal action to adopt the national MUTCD and they have two years to do that.
Each sign in the MUTCD has a code associated with it.
For example, the code for the Chevron Alignment sign is W1-8. Many practitioners refer to signs by their code rather than by their name.