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National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Notice of Termination of Interim Approval IA-5

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Federal Highway Administration (FHWA), Department of Transportation (DOT).




The Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) is incorporated in our regulations, approved by FHWA, and recognized as the national standard for traffic control devices used on all streets, highways, bikeways, and private roads open to public travel. This notice terminates the Interim Approval for Use of Clearview Font for Positive Contrast Legends on Guide Signs (IA-5), issued September 2, 2004, as authorized by Section 1A.10 of the MUTCD, and discontinues the provisional use of an alternative lettering style in traffic control device applications. The result of this termination rescinds the use of letter styles other than the FHWA Standard Alphabets on traffic control devices, except as provided otherwise in the MUTCD. Existing signs that use the provisional letter style and comply with the Interim Approval are unaffected by this action and may remain as long as they are in serviceable condition. This action does not create a mandate for the removal or installation of any sign. This action does not amend any provision of the MUTCD.


Effective 30 days after publication in the Federal Register.

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For questions about this notice, contact Mr. Kevin Sylvester, MUTCD Team Leader, FHWA Office of Transportation Operations, (202) 366-2161, or via email at . For legal questions, please contact Mr. William Winne, Office of the Chief Counsel, (202) 366-1397, or via email at Office hours are from 8:00 a.m. to 4:30 p.m., e.t., Monday through Friday, except Federal holidays.

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Numerous research efforts have taken place over the last 15 years with the goal of improving the legibility of highway signs. One area of focus has been on guide signs. As a result of some early studies,[1] FHWA issued an Interim Approval allowing provisional use of an alternative lettering style known as ClearviewTM for signs in positive contrast color orientations (lighter legend on darker background).[2] Although the research supported only one series of this lettering style, the Interim Approval was written in a way that would authorize narrower letter forms, to correspond to the system of the FHWA Standard Alphabets, in anticipation of successful future research evaluations. However, subsequent evaluations showed no benefit to the narrower letter forms and degraded sign legibility when compared to the corresponding FHWA Standard Alphabet series.[3] Additionally, tests of alternative lettering in negative contrast color orientations (dark legend on lighter background, such as for regulatory and warning signs) showed no improvement and significantly degraded legibility of the sign.[4] Start Printed Page 4084Ultimately, the consistent finding among all the research evaluations is that the brightness of the retroreflective sheeting is the primary factor in nighttime legibility.

The presence and availability of two separate letter styles with differing criteria have resulted in significant confusion and inconsistency in highway sign design, fabrication processes, and application. Although the terms of FHWA's 2004 Interim Approval are explicit, misunderstandings and misapplications of the provisional letter style have resulted. Inconsistent sign design practices are becoming more common and may have coincided with the provisional allowance of an alternative lettering style due to a lack of consistent implementation and inaccurate presumptions that lesser sign design criteria, such as reduced interline and edge spacing, are broadly acceptable. Additionally, many agencies believed that the alternative lettering style should be used in all applications and that all lettering should be displayed in upper and lowercase lettering, regardless of the type of message. There is also considerable confusion that the requirement of the MUTCD to display destination and street names in upper and lowercase lettering equates to the use of the provisional lettering style rather than the Standard Alphabets. In actuality, there is no interdependency between letter style and case.

Purpose of This Notification

Uniformity in the display of traffic control devices is central to the underlying foundation of the MUTCD. As such, FHWA establishes the criteria therein with uniformity in mind. This uniformity extends not only to the content of the message displayed, but also to the format and appearance of the display itself. Although seldom specifically identifiable by the motorist, non-uniformity of a sign display or sequence of signs might exhibit itself in less direct ways, such as diminished legibility requiring additional glance time directed toward a sign or group of signs instead of toward the traffic on the road.

The FHWA is committed to exploring solutions that can significantly contribute to enhanced road user safety and are readily and feasibly implemented. In this particular case, there is no benefit of the alternative method that cannot be similarly achieved within the established practice. In many cases, the established practice actually demonstrated benefits that the alternative could not achieve. The FHWA believes that devoting further resources to the development of an alternative will not yield dramatically different results that would warrant an institutional change.


Based on these findings, FHWA does not intend to pursue further consideration, development, or support of an alternative letter style. Accordingly, FHWA discontinues further implementation of an alternative letter style and terminates and rescinds the Interim Approval for new signing installations, except as otherwise provided in the MUTCD. Existing signs that use the provisional letter style and comply with the Interim Approval are unaffected by this action and may remain as long as they are in serviceable condition. This action does not create a mandate for the removal or installation of any sign. This action does not amend any provision of the MUTCD.

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Authority: 23 U.S.C. 101(a), 104, 109(d), 114(a), 217, 315, and 402(a); 23 CFR 1.32; and, 49 CFR 1.85.

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Issued on: January 15, 2016.

Gregory G. Nadeau,

Administrator, Federal Highway Administration.

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1.  Carlson, P.J., Evaluation of Clearview Alphabet with Microprismatic Retroreflective Sheetings, Report No. FHWA/TX-02/4049-1. Texas Transportation Institute, August 2001, resubmitted October 2001.

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2.  Interim Approval 5 can be accessed at the following Web address:​res-ia_​clearview_​font.htm.

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3.  Chrysler, S.T., P.J. Carlson, and H.G. Hawkins. Nighttime Legibility of Ground-Mounted Traffic Signs as a Function of Font, Color, and Retroreflective Sheeting Type, Report No. FHWA/TX-03/1796-2. Texas Transportation Institute, September 2002.

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4.  Holick, A., S.T. Chrysler, E. Park, and P.J. Carlson. Evaluation of the ClearviewTMFont for Negative Contrast Traffic Signs, Report No. FHWA/TX-06/0-4984-1. Texas Transportation Institute, January 2006, resubmitted April 2006.

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[FR Doc. 2016-01383 Filed 1-22-16; 8:45 am]