An established, rational process should be used for evaluating and replacing signs that, through its implementation, will address signs that likely do not meet adequate retroreflectivity levels.

Nighttime sign visibility should be evaluated at least every other year. When nighttime sign visibility is anticipated to fall below the criteria defined by the evaluation method selected for use by an agency, the signs should be scheduled for replacement as soon as conditions and resources permit.

An agency should use one of the following methods to evaluate sign retroreflectivity:

1. Minimum Sign Retroreflectivity Values: Measure sign retroreflectivity values in the field and compare to established minimum values.
2. Minimum Nighttime Sign Legibility Distances: Conduct nighttime inspections and judge the distance at which sign messages become legible.
3. Nighttime visual sign inspection by trained observers: Train inspectors on how to properly conduct retroreflectivity inspections and subjectively evaluate signs comparing to sample signs at the established minimum values.
4. Maximum service life of signs: Through documented evidence of deterioration rates of certain sheeting types, set up a maintenance program to replace signs prior to estimated end-of-service life based on the established minimum values.
5. Calibration Inspection Panels: Mount retroreflective sheeting inspection panels on a sign and view the sign and inspection panel from a set distance with a flashlight. Compare the relative brightness and replace signs that are less bright than the inspection panels.
6. A combination of the above methods or other methods endorsed by AASHTO and FHWA.

These methods have specific characteristics that should be used to meet the intent of this guidance. Those characteristics are described in _________________________.

Continued in Figure 18.

All signs are covered by this standard, with the exception of the following:

1. Externally illuminated specifically for that sign
2. Parking, Standing, and Stopping Signs (Series R7 & R8)
3. Walking/Hitchhiking/Crossing (R9, R10-1 through R10-4b)
4. Street Name Signs (D3) on local roads with speed limits of 30 mph or less
5. General Information (I Series)
6. Adopt-A-Highway
7. Tourist-Oriented Directional Signs (Chapter 2G)
8. Bikeways, including shared-use paths and bicycle lane facilities

SUPPORT:

Using one of the above evaluation methods indicates a reasonable effort is being made to analyze the appropriate level of retroreflectivity of traffic signs. It is still possible to inadvertently have individual signs with lower levels of retroreflectivity than desired. This inadvertent miss is not indicative of an inadequate evaluation process.

Supporting information on which to develop a sign replacement process using the above-recommended methods is available from the FHWA at ____________________.

Notes for Rulemaking:

Implementation Period:

From the time of Final Rule publication: Signs not meeting the minimums must be replaced by:

National Highway System – 5 years
All Rural – 7 years
All – 9 years

Or…

Regulatory – 5 years
Warning – 7 years
All – 9 years

Guidance:

Jurisdictions should establish a process to provide reasonable nighttime visibility of traffic signs. Nighttime sign visibility should be evaluated using one or a combination of the following methods:

• Nighttime sign inspections
• Expected sign life
• Calibration inspection panels
• Measured sign retroreflectivity values
• Control Signs
• Other established methods as appropriate

These methods are described in the FHWA document Guidelines for Nighttime Sign Visibility¹.
Signs should be scheduled for replacement when they are known to not meet a jurisdiction’s nighttime visibility criteria.

Option:

An agency may exclude the following signs from the above process:

1. Parking, Standing, and Stopping Signs (Series R7 & R8)
2. Walking/Hitchhiking/Crossing (R9, R10-1 through R10-4b)
3. Street Name Signs (D3) on local roads with speed limits of 30 mph or less
4. General Information (I Series)
5. Adopt-A-Highway
6. Bikeways, including shared-use paths and bicycle lane facilities

Support:

Reasonable nighttime visibility cannot be determined through retroreflectivity alone.

Note on Implementation and Compliance (to be a part of the rulemaking):
Agencies should implement a process within two years of the final rule. Agencies should replace signs to meet the criteria of the process within seven years of the final rule.

¹Guidelines for Nighttime Visibility of Traffic Signs, FHWA-RD-XX-XXX. [Note: this document will be developed by FHWA and will be included in the proposed rule. The title of the document may change.]

Guidance:

A process to provide reasonably adequate nighttime visibility should be used for evaluating and replacing signs. Signs that do not provide reasonable nighttime visibility should be replaced when reasonable.

Support:

The following methods can be used to determine reasonably adequate nighttime visibility:

1. Nighttime visual sign inspection: Signs are evaluated at night for reasonably adequate nighttime visibility at least every other year.
2. Sign Life: Based on documented information on expected sign life, signs are replaced before the end of the expected sign life.
3. Calibration Inspection Panels: Inspection panels are mounted on a sign and used to determine if a sign has reasonably adequate nighttime visibility. Mount retroreflective sheeting inspection panels on a sign and view the sign and inspection panel from a set distance with a flashlight. Compare the relative brightness and replace signs that are less bright than the inspection panels.
4. A combination of the above methods.
5. Other methods as appropriate.

These methods are described in [title of document].

Reasonably adequate nighttime visibility cannot be determined through retroreflectivity alone.

All signs are covered by a process, with the exception of the following:

1. Externally or internally illuminated specifically for that sign
2. Parking, Standing, and Stopping Signs (Series R7 and R8)
3. Walking/Hitchhiking/Crossing (R9, R10-1 through R10-4b)
4. Street Name Signs (D3) on local roads
5. General Information (I Series)
6. Adopt-A-Highway
7. Tourist-Oriented Directional Signs (Chapter 2G)
8. Bikeways, including shared-use paths and bicycle lane facilities

Note for Rulemaking:
Agencies should have five years to adopt a process.

Guidance:

An agency should establish a process to provide reasonable nighttime visibility of traffic signs. Signs that do not provide reasonable nighttime visibility should be replaced within a reasonable time frame.

Option:

An agency may exclude the following signs from a process to provide reasonable nighttime visibility:

1. Parking, Standing, and Stopping Signs (Series R7 and R8)
2. Walking/Hitchhiking/Crossing (R9, R10-1 through R10-4b)
3. General Information (I Series)
4. Adopt-A-Highway
5. Tourist-Oriented Directional Signs (Chapter 2G)
6. Specific services signs
7. Bikeways, including shared-use paths and bicycle lane facilities
8. Recreational/Cultural Interest signs
9. Blue D6 and D9 series signs

Agencies may use one or a combination of the following methods to best fit the needs of the agency to promote nighttime visibility of traffic signs:

• Nighttime sign inspections – Sign replacement is based in part on the results of visual nighttime inspections of signs.
• Sign management system – Sign replacement is based in part on information contained in a management system. Such information may include: date of installation, date of last inspection, type of sheeting material, measured retroreflectivity, direction of exposure, or other factors.
• Measured sign retroreflectivity values – Sign replacement is based in part on the measured retroreflectivity of signs.
• Sign age – Sign replacement is based in part on the expected life of the sign sheeting material.
• Control signs – Sign replacement is based in part on the performance of a sample of control signs that represent the performance of the larger population of related signs.

Support:

Reasonable nighttime visibility cannot be determined through retroreflectivity alone.

Name of document provides additional information about methods to promote nighttime sign visibility.

Note for rulemaking:
Need to provide five years for agencies to adopt a process.

Guidance:

An agency should establish a process to provide reasonable nighttime visibility of traffic signs. Signs should be scheduled for replacement when they are known not to meet an agency’s nighttime visibility criteria. Nighttime sign visibility should be evaluated using one or a combination of the following methods:

• Nighttime sign inspections
• Sign management system
• Measured sign retroreflectivity values
• Sign life
• Control signs
• Other methods as appropriate

These methods are described in [title should include the word “guideline”] _____________.

Option:

An agency may exclude the following signs:

1. Parking, Standing, and Stopping Signs (Series R7 and R8)
2. Walking/Hitchhiking/Crossing (R9, R10-1 through R10-4b)
3. Street Name Signs (D3) on local roads with speed limits of 30 mph or less
4. General Information (I Series)
5. Adopt-A-Highway
6. Bikeways, including shared-use paths and bicycle lane facilities

Support:

Reasonable nighttime visibility is determined though consideration of retroreflectivity and other factors.

Governmental units should provide and maintain traffic signs that have reasonable retroreflectivity. Target retroreflectivity values are published in [document title], however, they are not legal requirements.

Note for Rulemaking:
Agencies should adopt a process within two years. Agencies should replace signs to meet the criteria of the adopted process within seven years.

Section 2A.08 Retroreflectivity and Illumination

Support: [Note: Existing MUTCD language]

There are many materials currently available for retroreflection and various methods currently available for the illumination of signs. New materials and methods continue to emerge. New materials and methods can be used as long as the signs meet the standard requirements for color, both by day and by night.

Standard: [Note: Existing MUTCD language]

Regulatory, warning, and guide signs shall be retroreflective or illuminated to show the same shape and similar color by both day and night, unless specifically stated otherwise in the text discussion in this Manual of a particular sign or group of signs.

The requirements for sign illumination shall not be considered to be satisfied by street, highway, or strobe lighting.

Guidance: [Note: Existing MUTCD language]

All overhead sign installations should be illuminated unless an engineering study shows that retroreflection will perform effectively without illumination.

Option: [Note: Existing MUTCD language]

Sign elements may be illuminated by the means shown in Table 2A-1. [Note: Table not revised]

Retroreflection of sign elements may be accomplished by the means shown in Table 2A-2. [note: table not revised]

Guidance: [Note: New MUTCD language]

Jurisdictions should establish a management process to provide and maintain reasonable nighttime visibility of certain signs or classes of signs. Nighttime sign visibility should be evaluated using one or more of the following methods:

• Nighttime sign inspections
• Expected sign life
• Calibration inspection panels
• Measured sign retroreflectivity values
• Control signs
• Other established methods as appropriate

Signs should be scheduled for replacement when they are known to not meet a jurisdiction’s nighttime visibility criteria.

Continued in Figure 24.

Support: [Note: New MUTCD language]

Examples of typical methods are described in the FHWA document Guidelines for Nighttime Sign Visibility¹.

Reasonable nighttime visibility cannot be determined through retroreflectivity alone.

Note on Implementation (to be a part of the rulemaking)
Agencies should implement a process within two years of the final rule. Agencies should establish their own deadlines for complying with the criteria of their process.

¹Guidelines for Nighttime Visibility of Traffic Signs, FHWA-RD-XX-XXX. [Note: This document has not yet been developed. It will be developed by FHWA and included in the proposed rule. The title of the document may change.]