MUTCD Law Changes Part II: Minimum Retroreflectivity Requirements

Fri, 2011-03-11

In my previous post, I reviewed some of the changes to the definitions in the 2009 Edition of the Manual on Uniform Traffic Control Devices (MUTCD), published by the U.S. Department of Transportation Federal highway Administration (FHWA). 

As a reminder, any and all private roads that are open to public travel, even if they are owned privately, are required to apply the new standards.  This post will help inform you of some of the new retroreflectivity standards, and some methods you can use to determine if you are in compliance.

Traffic and street signs keep drivers and pedestrians safe.  Within the last decade, the amount of drivers over the age of 70 has increased significantly, and the trend will continue as the baby boomer generation moves towards their golden years. 

Having recognized that it becomes more difficult to see at night as anyone ages, the FHWA updated the minimum retroreflectivity requirements to aid drivers that have difficulty seeing traffic signs when driving at night.

In the next installment, we will discuss some of the required and optional color changes mandated by MUTCD.

What is Retroreflectivity?

Retroreflectivity is the light that you see bouncing off a sign vs. the light you see going into the sign.  As light bounces off a sign, the reflective material makes the sign appear brighter. 

Evaluating Signs

The updated MUTCD law requires that all signs in any jurisdiction must maintain a minimum level of retroreflectivity.  There are several methods that you can use to evaluate whether or not signs need to be replaced so that they are compliant.
Note: This information is a summary of the methods that could be used to determine whether a sign needs to be replaced.  Please visit the FHWA Website for more information, guidance, and updates on retroreflectivity.

Assessment Methods

The following procedures are recommended by the FHWA to evaluate individual signs.  They include:

Nighttime Inspection- Where an inspector uses low-beam headlights at normal speed and typical viewing distances.

Calibration Signs- Includes viewing a ‘calibration sign’ that helps the inspector establishes minimum retroreflectivity level thresholds prior to a nighttime inspection.   

Comparison Panels- This procedure requires a panel that is a representation of the minimum required retroreflectivity levels.  The panel is attached to the sign that needs to be evaluated and reviewed by an inspector.

Consistent Parameters- This Includes the factors that were used to develop the new minimum retroreflectivity which include using a 2000 or later sport model SUV or pickup truck and an inspector who is at least 60 years old.

Measured Sign Retroreflectivity- This uses the ASTM E1709 Standard for measuring retroreflectivity for signs using a portable retroreflectometer.

Management Methods

Management Methods are used to give agencies the ability to maintain minimum retroreflectivity without having to assess individual signs.  There are three ways to evaluate signs using these methods:

Expected Sign Life- Individual signs are replaced before the reach the end of their expected service life (when the sign degrades below the required minimum retroreflectivity levels). To ensure accuracy, a method for tracking sign age must be implemented.

Blanket Replacement- Based on time intervals and expected sign life, this method requires all signs within a replacement area or sign type be replaced- even if a sign has been recently installed.

Control Signs- A sample of signs is selected from the field or placed in a maintenance yard, and evaluated over time.  When these signs fall below minimum levels of retroreflectivity, all signs in the assigned area must be replaced.

New MUTCD Minimum Retroreflectivity Compliance Periods

  • Effective January 22, 2012- Implementation and continued use of an assessment or management method that is designed to maintain traffic sign retroreflectivity at or above the established minimum levels.
  • Effective January 22, 2015- Replacement of regulatory, warning, and ground-mounted guide (except street name) signs that are identified using the assessment or management methods as failing to meet the established minimum levels.
  • Effective January 22, 2018- Replacement of any street name signs and overhead guide signs that are identified using the assessment or management method as failing to meet the established minimum levels for retroreflectivity.

Every standard Stonehouse traffic sign is manufactured using high intensity reflective material that complies with the new minimum retroreflectivity requirements outlined by the FHWA and MUTCD.

View the retroreflectivity requirements discussed above in detail.

Source: US Department of Transportation Federal Highway Administration