Nighttime Visibility of Traffic Signs: Chapter 4 - Recommendations
The previous chapters describe a series of four, FHWA-sponsored, workshops on minimum levels of in-service sign retroreflectivity. The purpose of the workshops was to solicit input - primarily from city, county, and state transportation agency personnel - regarding the minimum levels of in-service sign retroreflectivity and the various means that agencies could use to implement the guidelines. These workshops provided three major benefits to the sponsor and the participants.
- The FHWA was able to identify the participants' concerns, impacts, and limiting factors associated with the implementation of minimum levels of sign retroreflectivity. This information will be helpful as the FHWA develops a proposed rule as well as technical assistance to help agencies improve the nighttime visibility of signs.
- The participating agencies were able to contribute to the process of developing the structure and content for minimum levels of retroreflectivity.
- The participants learned about visibility and retroreflectivity issues and the practices that can be used to improve nighttime sign visibility and sign retroreflectivity. Participant questions and comments in this area helped the FHWA identify training needs related to visibility and retroreflectivity.
The workshops were generally well received by the participants, and appreciated as an opportunity to comment on the concept of minimum sign retroreflectivity. The participants gained a better understanding of the importance of nighttime sign visibility and recognized the obligations of agencies to provide signs with reasonable nighttime visibility. In spite of these understandings, the majority of the public agency participants oppose changes to the MUTCD that introduce numerical retroreflectivity levels that need to be maintained or that eliminate agencies' flexibility to address nighttime sign visibility in a manner that is consistent with their available resources. The participants are more willing to accept a change to the MUTCD if they provide alternative methods for agencies to adopt and do not indicate specific retroreflectivity levels/criteria that must be met. A key desire of the public agency participants is that the MUTCD language be kept simple and flexible.
Given the range of opinions regarding minimum retroreflectivity levels, the participants worked together to develop recommendations for the FHWA to consider. This chapter describes the specific recommendations originating from the workshops that the FHWA should consider in developing the proposed rule for the Federal Register. These recommendations reflect the general opinions of the majority of the public agency workshop participants as interpreted by the report authors. The following recommendations address the three elements that are envisioned to comprise a proposed rule on minimum retroreflectivity levels - the proposed rule language, the MUTCD language, and the content of the supplemental document. This chapter also describes other recommendations that the FHWA should consider in developing the proposed rule.
Minimum guidelines for traffic sign visibility and/or retroreflectivity would be implemented through the standard federal rulemaking process. Proposed language changes to the MUTCD would be published in the Federal Register as a Notice of Proposed Amendments (NPA). Agencies and individuals would have an opportunity to comment on the proposed changes through the Federal Register docket. FHWA would evaluate the docket comments and use them to revise the proposed changes or determine that the proposed changes should not be made. If appropriate, the final rule would then be published in the Federal Register and implemented.
Based on input from the workshop participants, the proposed rule (NPA) should describe the objectives of the rule; present the proposed changes to MUTCD language; define the implementation time frame; describe the benefits of enacting the rule; describe the impacts on agencies; and define standard terminology for describing sign visibility and retroreflectivity concepts. The following recommendations address each aspect of the rulemaking language.
- Objectives:
- The objective of the proposed rule should be to improve the nighttime visibility of signs. It should not be to establish minimum levels of sign retroreflectivity.
- MUTCD language (note that recommendations for specific MUTCD language are presented in the next section):
- The MUTCD should establish the general objective to improve nighttime sign visibility and let agencies determine the best course of action for meeting the objective.
- The MUTCD should provide agencies with choices on which method(s) an agency uses to provide reasonable nighttime visibility.
- Any guidelines presented in the MUTCD should be recommendations ("should" language) and not a requirement ("shall" language).
- Minimum coefficient of retroreflectivity (RA) values should not be presented in the MUTCD. Minimum retroreflectivity values should be presented in a supplemental document that is referenced in the MUTCD.
- Implementation Time Frame:
- The proposed rule should indicate that agencies will have three years from the date of the final rule to implement a process that complies with the MUTCD guidelines and ten years after adopting a process to comply with the criteria of the adopted process.
- The participants recommended that there be some guidance on implementation priorities for meeting the guidelines. All of the following methods were mentioned as possibilities. There was no consensus on which one was preferred.
- By sign type - Guidelines should be implemented for regulatory signs first; then warning signs; and finally guide signs.
- By roadway class - Guidelines should be implemented first on the Interstate Highway System, then the National Highway System (NHS) (for those NHS roads that are not Interstate Highways), followed by U.S. and state highways. Local roads should be the last element of the implementation process. Another option would be to replace NHS signs first, rural roads second, and urban roads last.
- No priorities - Agencies can implement the guidelines in any priority they feel is appropriate.
- Benefits and Impacts:
- The proposed rule should identify the potential expected benefits of improving sign visibility.
- If the information is available, the expected benefits should address: the crash reductions associated with prior efforts to improve sign visibility, the crash reductions that are expected to be associated with a national program to improve nighttime sign visibility; and/or the improvements in signing operations that agencies can realize by better managing their signing resources.
- The proposed rule should describe the expected costs associated with implementing the MUTCD guidelines. All associated costs should be noted, including signing materials, training, equipment, and staff time to develop processes and procedures.
- Terminology:
- The workshop participants used a range of terms to describe sign assessment and management practices and various visibility and retroreflectivity concepts. To improve communication and understanding of the proposed changes, the FHWA should define several key terms. Examples of terms that should be defined include: sign management system, sign inventory, sign management practices, evaluation methods, sign inspection, sign infrastructure, retroreflectivity measurement, and asset management methods.
The previous chapter described the process used in each workshop to develop individual workshop recommendations for MUTCD language on minimum sign retroreflectivity. After reviewing the MUTCD recommendations from each workshop and incorporating other factors that affect nighttime sign visibility, the facilitators developed two recommendations for MUTCD language. One recommendation makes minimal changes to the 2000 MUTCD. The other recommendation provides new language for the minimum retroreflectivity section (Section 2A.09) that was reserved for the future in the 2000 MUTCD. Either alternative should represent the starting point for the development of a proposed rule. However, other factors that are considered in the process of developing the proposed rule may necessitate changes to the recommended MUTCD language. The differences in the two alternatives are explained below.
- Minimal Change- This recommendation, which is presented in Figure 10, reflects minimal change to the 2000 MUTCD language. The recommended changes are related to revising and expanding the description of "adequate retroreflectivity" contained in Section 2A.23, which was added to the 2000 MUTCD. If the minimal change option is used, then Section 2A.09 could be deleted from the MUTCD. Some of the recommended changes to Section 2A.23 should be considered even if the most significant changes are implemented through Section 2A.09.
- New Section- This recommendation, which is presented in Figure 11, is based on developing language for Section 2A.09, which is reserved in the 2000 MUTCD for future language on minimum levels of retroreflectivity. The terminology used to describe the various methods may need to be refined as the procedures associated with these methods are developed.
Figure 10. Minimal Change Recommendation for MUTCD Language
| Section 2A.23 Maintenance
Guidance:
All traffic signs should bekept properly positioned, clean, and legible, and should have adequate retroreflectivityreasonably maintained. Maintenance activities should consider proper position, cleanliness, legibility, and daytime and nighttime visibility of a sign. Damaged or deteriorated signs should be replaced.
Support:
The FHWA document Guidelines for Nighttime Sign Visibility provides information about methods that can be used to assess and maintain nighttime sign visibility.
Guidance:
To assure adequate maintenance, a schedule for inspecting (both day and night), cleaning, and replacing signs should be established. Employees of highway agencies, police, and other public agencies whose duties require that they travel on the roadways should be encouraged to report any damaged, deteriorated, or obscured signs at the first opportunity.
Steps should be taken to see that weeds, trees, shrubbery, and construction, maintenance, and utility materials and equipment do not obscure the face of any sign. A regular schedule of replacement of lighting elements for illuminated signs should be maintained.
Note: underline indicates additions to existing language andstrikeoutindicates deletions of existing language.
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The workshop participants consistently indicated that minimum coefficient of retroreflectivity (RA) values should not be included in the MUTCD itself. Instead they should be published in a supplemental document, along with information about the other implementation options that are described in the MUTCD.
- Some workshop participants prefer that a supplemental document with minimum retroreflectivity values not be identified by name in the MUTCD. Other participants (especially local agency participants) indicated that they have no way to know about the document if it is not identified by the MUTCD. Many of the participants indicated that putting the minimum retroreflectivity values in a supplemental document would be acceptable.
- The supplemental document should provide information on the various methods for improving nighttime sign visibility, not just the minimum retroreflectivity values.
- Language in the supplemental document should clearly indicate that it is not a legal document and it should not carry any recommendations or mandates.
- The supplemental document should be available at no cost to agencies. Internet access is the preferred means for making the document available.
Figure 11. New Section Recommendation for MUTCD Language
| 2A.09 Nighttime Sign Visibility Minimum Retroreflectivity Levels
Guidance:
The agency or public official having jurisdiction should establish a process to provide and maintain reasonable nighttime sign visibility. As recommended in Section 2A.23, an agency should conduct nighttime visual inspections of traffic signs to determine the need for replacement or other corrective measures.
Option:
In addition to nighttime inspections, agencies may use one or more of the following methods to assess the retroreflectivity aspect of nighttime sign visibility:
- Scheduled replacement – Signs are replaced before they reach the end of the expected retroreflective life.
- Inspection panels – Panels are used to judge retroreflectivity.
- Measured sign retroreflectivity – An instrument is used to measure retroreflectivity.
- Control signs – Performance of a sample of signs is used to determine replacement of all signs.
- Other appropriate methods – Other methods, or a combination of methods, that provide a reasonable level of nighttime sign visibility may be used.
When one of these methods is used, the level of detail associated with the nighttime inspection may be reduced to a confirmation of the selected method(s).
Option:
An agency may exclude the following signs from nighttime visual inspections and other methods of assessing nighttime sign visibility:
- Parking, Standing, and Stopping Signs (R7 and R8 series).
- Walking/Hitchhiking/Crossing (R9 series, R10-1 through R10-4b).
- General Information (I Series).
- Adopt-A-Highway.
- Tourist-Oriented Directional Signs (Chapter 2G).
- Bikeways, including shared-use paths and bicycle lane facilities.
Support:
The FHWA document Guidelines for Nighttime Sign Visibility provides additional information about methods to assess nighttime sign visibility.
Note: all language in this section is new language except for the title.
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The workshop participants also identified other recommendations, although they may not be a part of the proposed rule. These recommendations include:
- Federal funding should be provided to agencies for the additional costs associated with improving the nighttime visibility of signs, such as improved evaluation methods, sign management processes, and sign replacement efforts. While the workshops did not identify a specific amount of funding that would be needed, the following issues related to funding were identified:
- Federal funds should support the implementation of new or improved sign evaluation or management practices, including software systems and sign inventories.
- Federal funds should also support the replacement of signs that do not meet the visibility guidelines.
- Funds should be available for use in any of the following activities: material costs; staff time and labor costs; training; software; equipment; and other resources that will be needed by agencies to comply with the new guidelines.
- Funding for local agencies should go directly to local agencies and not go through the state transportation agency.
- Finally, Appendix I presents numerous questions that the FHWA should consider in developing the guidelines for nighttime sign visibility. Many of these questions were raised in one or more of the workshops and are addressed in the report. Some of the questions were raised by participants or facilitators outside of the workshop activities, but have been included in the appendix so that they can be considered as part of a thorough rulemaking effort.
