Manual on Uniform Traffic Control Devices (MUTCD) arrows logo

Incoming Interpretation Letter 8(09)-001(I) - Width of Retroreflective Strip on Round Support

PDF Version, 1.1MB

You will need the Adobe Acrobat Reader to view the PDF on this page.

CTC Campbell Technology Corporation
Richard M. Campbell
6100 Southwest Boulevard Suite 500
Fort Worth, TX 76108

Phone: (817 886-8210
Fax: (817) 886-8225

January 18, 2010

Mr. Mark Kehrli
Director, Office of Transportation Operations
Federal Highway Administration
1200 New Jersey Avenue, SE
Mail Stop E86-201
Washington, DC 20590

RE: 2009 MUTCD
Request for Interpretation - Part 8

Dear Mr. Kehrli:

It has come to my attention that there is an area within Part 8 of the 2009 MUTCD where clarification is necessary to assure compliance with the new 2009 MUTCD Standard regarding Crossbuck Assemblies. The specific issue concerns the vertical strip of retroreflective material which is required on the front and back of the support for a Crossbuck Assembly. The Standard addressing this issue is contained in Section 8B.04 entitled Crossbuck Assemblies with YIELD or STOP Signs at Passive Grade Crossings and is specifically contained in paragraph 15.

The Standard states:

A vertical strip of retroreflective white material, not less than 2 inches in width, shall be used on each Crossbuck support at passive grade crossings for the full length of the back of the support from the Crossbuck sign or Number of Tracks plaque to within 2 feet above the ground, except as provided in Paragraph 16.

Figures 8B-2and 8B-3 Sheets 1 and 2 further identify the location and placement of the strip on a Crossbuck Assembly.

The need for interpretation arises where a Crossbuck Assembly is mounted on a round pole. Some agencies have encouraged railroads to use a triangular slipbase system as a part of the crossbuck assembly which requires the use of a metal pole in lieu of the traditional wood post. In these cases, it is desirable to affix the retroreflective material directly to the pole. A minimum pole diameter (OD) of 2 ½ inches is required in this application. In order to comply with the Standard, it is proposed that a minimum 3 inch wide retroreflective strip be applied directly to the front and to the back of the pole resulting in a curved strip slightly wider than 2 inches. With a circumference of 7.85 inches, the result is that greater that 75 percent of the pole surface is covered with retroreflective material. There are a number of benefits to this method of applying the required strips:

  1. The 3 inch strip applied to the curved surface provides a functional equivalent to the 2 inch strip applied to a flat surface.
  2. The strip applied directly to the pole provides retroreflective material to the sides as well as to the front and back of the pole which results in increased conspicuity for road users approaching from an intersecting roadway or driveway.
  3. The strip is subject to less damage if affixed directly to the pole.

It is my belief that the application of the 3 inch retroreflective strip directly to the curved surface of the pole is a functional equivalent to the application of a 2 inch wide strip to a flat surface and it is that equivalency for which I am seeking this interpretation as complying with the subject Standard.

Thank you for your assistance in this matter.


Original signed by:


Richard M. Campbell

Reply Letter