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Minimum Levels of Retroreflectivity

The FHWA Minimum Levels of Retroreflectivity Ruling, originally established in January of 2008, was revised in June of 2012. Following is a summary of changes:

  • The compliance date to implement and use an assessment or management method designed to maintain regulatory and warning sign retroreflectivity at or above the established minimum levels is June 13, 2014.
  • The compliance date for replacement of signs identified as not meeting minimum retroreflectivity levels has been eliminated; however, elimination of the compliance date does not eliminate the regulatory requirement to comply with the MUTCD Standard. Even without a specific date, agencies still need to replace signs they identify as not meeting the established minimum retroreflectivity levels. According to the FHWA:
    • Signs identified through an agency‘s method as below the minimum established retroreflectivity levels have exhausted their useful service life and need to be replaced because they do not meet the needed function of being adequately visible at night. Similar to other occurrences of signs that are no longer serviceable, agencies are expected to prioritize replacement of these signs based on engineering considerations such as the relative importance of the sign to the safety of the road user, volumes and speed of nighttime traffic, and optimal use of limited resources, among others. Signs that are no longer serviceable might demand a higher priority for replacement over other non-compliant signs that are replaced by systematic upgrading or routine maintenance schedules.
  • While minimum performance levels still exist for guide and street name signs, these types of signs are excluded from the assessment/management method compliance date. The final rule states that "types of signs other than regulatory or warning are to be added to an agency’s management or assessment method as resources allow."
  • The final rule adds a new Option statement exempting existing historic street name signs within a locally identified historic district from the Standards regarding color, letter size, and other design features, including retroreflectivity.

Summary of the Minimum Maintained Retroreflectivity Levels Table

White copy on overhead guide signs must be made from prismatic sheeting.

White copy on ground mounted street name signs cannot be made from Type I sheeting.

Warning signs (black on yellow or orange) cannot be made from Type I sheeting.

Regulatory signs (black on white) must retain a minimum retroreflectivity level of ≥ 50 cd/lx/m² (while use of Type I sheeting—with an initial retroreflectivity value of 70 cd/lx/m²--is allowed, sign life will be short and may result in poor life cycle value).

Warning signs (black on yellow or orange) cannot be made from Type I sheeting.

Summary of Assessment/Management Methods

Method Process
Visual Nighttime Inspection Trained sign inspector, moving vehicle
Measured Retroreflectivity Measure signs with a retroreflectometer
Expected Life Determine expected life, replace at end of service life
Blanket Replacement All signs in a corridor or of a specific type are replaced at specific intervals
Control Signs Replacement based on performance of control signs
Other Engineering-based Methods Varies with method

Potential funding sources for sign replacement programs include:

    National Highway System
    Surface Transportation Program
    Interstate Maintenance Program (IMP)
    Highway Safety Improvement Plan (HSIP)
    High Risk Rural Roads (HRRR)

Under MAP-21, "minimum levels of retroreflectivity" projects were added to the list of safety improvement that can be funded at up to 100 percent federal share, and these types of projects do not have to be prioritized in the state's Strategic Highway Safety Plan to receive HSIP funding.

To learn more about bright, durable 3M prismatic reflective sheeting, traffic sign upgrade services and flexible funding programs, contact your 3M representative or contact us.

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More Information

For details and additional information about the Minimum Levels of Retroreflectivity Ruling, we recommend reviewing:

FHWA’s Sign Retroreflectivity Toolkit