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Action: Use of Changeable Message Signs Promoting Traffic-Related Voting Access Information (October 3, 2022)

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U.S. Department of Transportation Federal Highway Administration


MUTCD – Use of Changeable Message Signs Promoting Traffic-Related Voting Access Information
Date: October 3, 2022
From: Mark R. Kehrli /s/ Mark R Kehrli
Director, Office of Transportation
In Reply Refer To:
To: Division Administrators
Federal Lands Highway Division Engineers
Empty Cell

This memorandum provides information regarding the use of Changeable Message Signs (CMS) for promoting access to polling sites. This memorandum does not create a mandate on the use of CMS, but rather offers information on the appropriate and effective use of the devices in accordance with the Manual on Uniform Traffic Control Devices for Streets Highways (MUTCD). Please share this information with local jurisdictions through your State transportation departments.


Executive Order 14019, Promoting Access to Voting, issued on March 7, 2021, states, "[i]t is the responsibility of the Federal Government to expand access to, and education about, voter registration and election information, and to combat misinformation, in order to enable all eligible Americans to participate in our democracy." 86 FR 13623 (Mar. 10, 2021). Actions identified for FHWA necessitate cooperative implementation with State and local transportation officials and include the following:

(1) Support Traffic Analysis
Encourage transportation agencies to understand potential traffic impacts and identify actions to address traffic impacts on access to polling sites.

(2) Minimize Traffic Delays Related to Road Work
Encourage transportation agencies to proactively address any adverse work zone impacts on access to polling sites by implementing appropriate work zone management strategies.

CMS are traffic control devices that can be effective tools for providing real-time traffic regulatory, warning, or navigational information to the traveling public. In most cases, the messages displayed on CMS are related to traffic delays, travel times, lane closures, rerouting due to traffic incidents, and similar information to actively manage changing traffic conditions on the roadway system. With few exceptions, the MUTCD limits the use of CMS to the display of traffic operational, regulatory, warning, and navigational information. The provisions for using and displaying messages on CMS are in Chapters 2L and 6F of the MUTCD. In addition, clarification and interpretation of the MUTCD provisions for “Uses of and Nonstandard Syntax on Changeable Message Signs,” was issued on January 4, 2021, in FHWA Official Ruling No. 2(09)-174 (I).1

Using CMS for Voting-Related Traffic Information:
FHWA activities supporting the Executive Order center on encouraging discussion about good traffic management practices and planning for voting as a special event from a transportation perspective. Operational strategies to address potential traffic impacts in the immediate vicinity of polling sites within a precinct may consider how CMS could effectively communicate unique or changing traffic information to road users. Permanent and portable CMS may be used on, and leading up to, election day to inform road users of anticipated traffic impacts, changes to traffic patterns, or vehicle access and parking at the polling sites. Safety of all road users and orderly movement of traffic are of foremost concern. If used, CMS messages shall be limited to providing relevant traffic regulatory, warning, or navigational information to improve traffic operations and safety.2

The provisions of Chapters 2L and 6F of the MUTCD contain pertinent information and typical applications of permanent and portable CMS. This information includes requirements for CMS message legibility, visibility, design, and construction. In addition, other parts of the MUTCD contain provisions on the use of traffic control devices in general, and signs in particular, that are equally important. The engineering principles and processes that are involved in the specification of traffic control devices, including CMS messaging, to implement various traffic operations strategies are described in Section 1A.09 of the MUTCD. The traffic control devices are approved by the agency having jurisdiction over the roadway on which they are implemented.3

Official Ruling No. 2(09)-174 (I) provides information on the use of CMS in accordance with the provisions of the MUTCD. The memorandum details the five principles found in the MUTCD of an effective traffic control device that are applied when constructing messages: (1) fulfill a need; (2) command attention; (3) convey a clear, simple meaning; (4) command respect from road users; and (5) give adequate time for proper response. The application of these principles and those described in the Official Ruling will help ensure that any messages displayed convey the information intended in an effective manner and minimize any undue informational load imposed on the road user.

Some of the considerations stated in the MUTCD for developing CMS messages are reiterated here as a quick reference on some of the more common aspects. CMS messages shall not include advertising, animation, rapid flashing, dissolving, exploding, scrolling, or other dynamic elements.4 In addition, to help ensure that messages convey a clear and simple meaning understood by all and command the respect of the road user, the messages displayed on CMS should display conventional English syntax and not include witticisms, colloquialisms, and popular culture references.5 Messages shall consist of no more than two phases and no more than three lines of legend per phase, and each phase should be capable of being understood by itself.6 Portable CMS should be limited to eight characters per line or should consist of a full-matrix display.7 Additional provisions on CMS and portable CMS message construction can be found in MUTCD Sections 2L.05 and 6F.60.

The following examples illustrate acceptable single- and dual-phase messages. The need to use two phases instead of a single phase will depend on the size and capabilities of the CMS to accommodate the message.

a) Single-phase messages (full-matrix display)

Example 1a

Example 2a


b) Dual-phase messages (display limited to 8 characters per line) Example 1b Example

Example 1b
Example 2b


Phase 1


Phase 1


Phase 1


Phase 1

Example 1 provides information about expected traffic conditions. Example 2 provides navigational information to polling facility parking.

CMS can be an effective tool as part of a comprehensive traffic management strategy developed by States or local transportation officials to provide real-time traffic guidance and information for the purpose of reducing delays and ensuring effective access to polling sites. It is important that messages displayed on these signs adhere to the fundamental principles of effective traffic control devices and the provisions of the MUTCD. Knowledgeable traffic engineering staff trained in traffic signing can help ensure effective messaging that results in efficient traffic operation.

Additional resources related to traffic management during voting events are available at

Please direct any inquiries regarding the CMS provisions in the MUTCD or FHWA’s Official Ruling No. 2(09)-174 (I) to Mr. Marty Calawa,, of the Office of Transportation Operations MUTCD Team.

Except for any statutes or regulations cited, the contents of this memorandum do not have the force and effect of law and are not meant to bind the States or the public in anyway. This memorandum is intended only to provide information regarding existing requirements under the law or agency policies.

Associate Administrators
Chief Counsel
Chief Financial Officer
Directors of Field Services
Chief Technical Services Officer


1 Official Ruling No. 2(09)-174 (I), "Uses of and Non-Standard Syntax on Changeable Message Signs," may be accessed at the following Web address:

2 Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) 2009 Ed. § 2L.01, ¶ 3.

3 Id.; § 1A.08, ¶¶ 1-2.

4 Id.; § 2L.04, ¶ 1.

5 Official Ruling No. 2(09)-174 (I).

6 MUTCD § 2L.05, ¶ 4.

7 Id.; § 6F.60, ¶ 13.