Sign Retroreflectivity

Adequately maintained retroreflective signs improve highway safety and prevent roadway departure crashes by bouncing light from vehicle headlights back toward the vehicle and the driver's eyes, making the signs appear brighter and easier to see and read. Because the retroreflective properties of traffic control devices deteriorate over time, highway agencies need to actively manage the maintenance of signs in order to ensure that they are clearly visible at night.

Frequently Asked Questions

Here‘s where to find the answers to the most frequently asked questions about the Federal requirements for maintaining minimum sign retroreflectivity:

  1. What are the current requirements for sign retroreflectivity?
  2. Without compliance dates for replacing signs, when would signs identified through an agency‘s assessment or management method as not meeting the minimum retroreflectivity levels need to be replaced?
  3. What information is available to assist in the implementation of the new requirements for minimum sign retroreflectivity?
  4. How can highway officials assure that they are meeting the new provisions for retroreflectivity and that their signs provide reasonable visibility at night?
  5. If I select the visual inspection method, is the only real requirement that my inspector be trained?
  6. Can the retroreflectivity visual inspection rating be performed using a nighttime photolog?
  7. Why are signs with blue or brown backgrounds excluded from these retroreflectivity requirements?
  8. Can I use any type of sign sheeting as long as its retroreflectivity meets the minimum specified levels?
  9. Can I still use Type I Engineering Grade sign sheeting?
  10. What sheeting should I use for my agency?
  11. Table 2A-3 indicates that ASTM Type III white beaded sheeting cannot be used for overhead signs.  If existing overhead signs are lighted, is Type III allowed?
  12. What are the minimum values for fluorescent colors?
  13. Why are different numbers shown for green on overhead signs? For example. type I = 7, type II = 15 and type III = 25. If 7 is sufficient for type I why wouldn't it be the minimum level for all other types? On the other hand, if 25 is the minimum for type III how can 7 be acceptable for type I?
  14. Is there a sign inventory program available for local agencies to use?
  15. What is retroreflectivity?
  16. What makes the traffic signs visible at night?
  17. Why is the FHWA concerned about the visibility of traffic signs at night?
  18. What is the MUTCD?
  19. Why are requirements for sign retroreflectivity included in the MUTCD?

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Program Contact

Cathy Satterfield

What's New

FHWA Resource Charts, July 2013

FHWA Roadway Lighting Handbook, August 2012

RwD Strategic Plan, April 2013

Updated Guidance on Sign Retroreflectivity, April 2013

Clarifying Guidance on Daytime Luminance, January 2013

Guidance for the Selection , Use and Maintenance of Cable Barrier Systems, November 2012