National Academies Press: OpenBook

Solid-State Roadway Lighting Design Guide: Volume 2: Research Overview (2020)

Chapter: Chapter 2. Current State of SSL Adoption and Guidance

« Previous: Chapter 1. Introduction
Page 12
Suggested Citation:"Chapter 2. Current State of SSL Adoption and Guidance." National Academies of Sciences, Engineering, and Medicine. 2020. Solid-State Roadway Lighting Design Guide: Volume 2: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/25679.
×
Page 12
Page 13
Suggested Citation:"Chapter 2. Current State of SSL Adoption and Guidance." National Academies of Sciences, Engineering, and Medicine. 2020. Solid-State Roadway Lighting Design Guide: Volume 2: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/25679.
×
Page 13

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

5 CHAPTER 2. CURRENT STATE OF SSL ADOPTION AND GUIDANCE INTRODUCTION The overarching goal of the survey is to understand how SSL has been adopted in roadway lighting applications. More specifically, the survey provides information on the use of LEDs for roadway lighting, implementation of adaptive lighting strategies, and design/construction-related modifications currently used by state transportation agencies and authorities. SURVEY METHODS The survey was designed to understand how SSL has been adopted for roadway lighting and the design criteria and management associated with it. The survey has a list of 13 multiple-choice questions and was developed to understand the following areas: • State of adoption, construction, and maintenance of LED roadway lighting • Design guidelines, criteria, and review for LED roadway lighting SURVEY RESULTS The survey was distributed to 49 respondents from several state DOTs in the United States. The survey response rate was 61%. The results for all of the questions collected in September 2017 are in Appendix A. Survey results are summarized below. State of Adoption, Construction, and Maintenance of LED Roadway Lighting Eleven percent of the respondents reported that 25% of their roadway lighting systems are currently using LEDs. Approximately 7% of those who responded do not have any LED roadway lighting installed. About 68% of the respondents reported that all new roadway lighting installations use LED lighting, while 15% of respondents reported that new lighting installations do not use LEDs. A small percentage of respondents reported the use of HPS lighting for new installations. A significant majority of respondents (> 90%) reported that LED roadway lighting projects are currently in design, construction, or installed and fully operational. Approximately 43% of all the LED roadway lighting use a CCT of 4000K. A small number of the respondents use 3000K (12%) or 5000K (14%) CCTs; the rest of the respondents use a combination of CCTs. A majority of the respondents (63%) reported that during spot replacement, luminaires are replaced with similar luminaires. About 22% of the respondents reported that they allow for mixed sources when luminaires fail. A majority of the respondents (88.5%) reported that they do not use adaptive lighting control systems for LED roadway lighting. Only 11.5% of respondents use some sort of adaptive lighting control system for reduced illumination. Similarly, about 93% of the respondents do not use any kind of design modifications like occupancy sensors or color tuning when using LED roadway lighting.

6 Design Guidelines and Criteria for LED Roadway Lighting More than half (68%) of the respondents do not have a design manual or standard specifically for LED roadway lighting. However, 63% of the respondents have specific construction technical specifications for LED roadway lighting. More than 80% of the respondents use either ANSI/IES RP-8 (40%) or the AASHTO Roadway Lighting Design Guide (48%) for roadway lighting guidelines. Approximately 11% of respondents use roadway lighting guidelines that were developed in-house. A majority (70%) of respondents reported that if a national design and technical specification manual were available specifically for LED roadway lighting, they would use it. None of the respondents said they would not use it. Most respondents (~82%) reported that lighting calculations for roadway lighting designs are required to be reviewed. Approximately 15% of the respondents reported that lighting calculations are reviewed based on the size of the project. However, only 23% of respondents indicated that lighting levels need to be verified after construction and prior to acceptance. Forty-six percent of the respondents reported that they do not require verification of light levels after construction, and about 31% sometimes require verification. CONCLUSION Based on the results of the survey, the following conclusions can be drawn: • Even though LED roadway lighting systems are not currently widely installed, their adoption is growing rapidly; almost all new roadway lighting construction will use LEDs. • A majority of LED roadway lighting use 4000K CCT luminaires. • Adaptive lighting technologies and other design modifications that support reduced illumination are not widely used at present. • While the majority of the respondents do not have LED-specific roadway lighting design guidelines, they are willing use them if guidelines were available. In the absence of such guidelines, DOTs are using either ANSI/IES RP-8 or the AASHTO Roadway Lighting Design Guide for guidance on roadway lighting. • Although a majority of the DOTs require lighting calculations as part of the design review, very few verify lighting levels after construction.

Next: Chapter 3. Structure of SSL Guide »
Solid-State Roadway Lighting Design Guide: Volume 2: Research Overview Get This Book
×
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Providing light beyond the limits of the roadway travel lanes benefits drivers’ visual performance, spectral content of light-emitting diode (LED) sources should be a design consideration, and there are not currently any health impacts from properly designed roadway lighting are among the findings of this survey report.

The TRB National Cooperative Highway Research Program's pre-publication draft of NCHRP Research Report 940: Solid-State Roadway Lighting Design Guide: Volume 2: Research Overview determines the current guidance for the use of Solid State Lighting (SSL); identifies the research that still needs to be accomplished to assist in its proper implementation; and develops a comprehensive, easy to use, set of guidelines using currently available information and new research being proposed as part of this project.

Also see this guide's accompanying pre-publication draft, NCHRP Research Report 940: Solid-State Roadway Lighting Design Guide: Volume 1: Guidance.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!