Color Effectiveness of Yellow Pavement Marking Materials: Full Report (2008)

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.

ACKNOWLEDGMENT This work was sponsored by the American Association of State Highway and Transportation Officials (AASHTO), in cooperation with the Federal Highway Administration, and was conducted in the National Cooperative Highway Research Program (NCHRP), which is administered by the Transportation Research Board (TRB) of the National Academies. COPYRIGHT PERMISSION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FMCSA, FTA, Transit Development Corporation, or AOC endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. DISCLAIMER The opinion and conclusions expressed or implied in the report are those of the research agency. They are not necessarily those of the TRB, the National Research Council, AASHTO, or the U.S. Government. This report has not been edited by TRB.

iv TABLE OF CONTENTS LIST OF FIGURES ............................................................................................................ vi LIST OF TABLES ................................................................................................................x ACKNOWLEDGEMENTS .............................................................................................. xii CHAPTER 1: INTRODUCTION AND RESEARCH APPROACH ...............................1 Research Approach .....................................................................................................1 CHAPTER 2: PAVEMENT MARKING PRACTITIONER AND MANUFACTURER SURVEY ............................................................................................3 CHAPTER 3: COLOR BOOTH EXPERIMENT .............................................................7 Method ........................................................................................................................7 Results.........................................................................................................................8 Summary of Findings..................................................................................................8 CHAPTER 4: DARK-ROOM REAR-PROJECTION SCREEN EXPERIMENT ......18 Method ......................................................................................................................18 Results.......................................................................................................................22 Response Time Analysis.....................................................................................27 Summary of Findings................................................................................................27 CHAPTER 5: FIELD EXPERIMENT .............................................................................28 Method ......................................................................................................................28 Pavement Marking Materials....................................................................................30 Subjects .....................................................................................................................30 Apparatus ..................................................................................................................30 Experimental Design.................................................................................................30 Experimental Procedure............................................................................................31 Results.......................................................................................................................32 Conclusions...............................................................................................................38 CHAPTER 6: FIELD MEASUREMENTS ......................................................................41 Identification of the Instruments Capable of Making Field Measurements .............41 Development of a Protocol for Characterizing and Calibrating the Field Instruments.......................................................................................................42 Development of a Protocol for Validating the Field Instruments.............................50 Selection of States for Field Measurements..............................................................57 Execution of the Test Plan in NTPEP Test Decks....................................................57

v Daytime Measurements ............................................................................................58 Nighttime Measurements ..........................................................................................69 Lead and Lead Free Measurements ..........................................................................77 CHAPTER 7: DISCUSSION AND CONCLUSIONS .....................................................79 Recommendations.....................................................................................................82 REFERENCES....................................................................................................................85 APPENDIX A: SURVEY ...................................................................................................86 APPENDIX B: COLOR BOOTH EXPERIMENT DATA .............................................99 APPENDIX C: REAR-PROJECTION EXPERIMENT DATA ..................................108 APPENDIX D: FIELD EXPERIMENT .........................................................................123

vi LIST OF FIGURES Figure 1. Percentage of Yellow Classification under Nighttime Foveal Viewing Conditions adjusted for Illuminant A .......................................................................10 Figure 2. Percentage of White Classification under Nighttime Foveal Viewing Conditions adjusted for Illuminant A .......................................................................11 Figure 3. Percentage Yellow Classification under Daytime Foveal Viewing Conditions adjusted for Illuminant D-65 ..................................................................12 Figure 4. Percentage White Classification under Daytime Foveal Viewing Conditions adjusted for Illuminant D-65.....................................................................................13 Figure 5. Percentage of Yellow Classification under Nighttime Peripheral Viewing Conditions adjusted for Illuminant A .......................................................................14 Figure 6. Percentage of White Classification under Nighttime Peripheral Viewing Conditions adjusted for Illuminant A .......................................................................15 Figure 7. Color Classification under Daytime Peripheral Viewing Conditions adjusted for Illuminant D-65. ..................................................................................................16 Figure 8. Percentage of White Classification under Daytime Peripheral Viewing Conditions adjusted for Illuminant D-65. .................................................................17 Figure 9. A sample output of POV-Ray with high roadway luminance and high pavement marking luminance at ambient 0.5 cd/m2. ...............................................19 Figure 10. Selected Pavement Marking Color Configurations on CIE 1931 Standard 20 Observer Chromaticity Diagram...............................................................................21 Figure 11. Magnified Illustration of Initial and Final Chromaticities........................................22 Figure 12. Yellow Response Percentages Overlaid on The CIE 1931 Chromaticity Diagram.....................................................................................................................24 Figure 13. A Magnified View of the Yellow Response Percentages Overlaid on the CIE 1931 Chromaticity Diagram .....................................................................................25 Figure 14 Experimental layout administered in the field experiment............................................29 Figure 15. Percentage of yellow responses for each material at each distance, grouped by distance. ....................................................................................................................33 Figure 16 Percentage and number of yellow responses for each material at each distance, grouped by material type. .........................................................................................34 Figure 17. Normalized percentage of yellow responses for HID and TH headlamps for each material at each distance...................................................................................35 Figure 18. Material Chromaticity as a Function of Headlamp Type, Material Type, and Viewing Distance......................................................................................................37 Figure 19 Chromaticity trajectories of each pavement marking material as a function of distance under TH and HID illumination on the CIE 1976 u’ v’ color space..........................................................................................................................38

vii Figure 20. A schematic of the diffuse/30-m viewing geometry shows that a specular (bold line) and retroreflecting (dashed line) component that is collected by the detector................................................................................................................42 Figure 21. The ceramic tiles were placed in the nighttime instrument approximately normal to the illumination and observation axis.......................................................43 Figure 22. The nighttime instrument source was measured at a normal geometry....................45 Figure 23. The illumination spectral power distribution of the nighttime instrument compared to CIE illuminant A..................................................................................45 Figure 24. The SIRRCUS facility is composed of lasers and sphere sources used to illuminate the portable instrument. ...........................................................................46 Figure 25. The relative response of the nighttime instrument is plotted versus wavelength. ...............................................................................................................47 Figure 26. The relative responsivity of the nighttime instrument multiplied by the nighttime instrument illuminant compared to CIE illuminant A multiplied by the CIE color matching functions. ............................................................................48 Figure 27. The d/30m instrument source was measured in the sample plane. ...........................49 Figure 28. The illumination spectral power distribution of the d/30m instrument compared to CIE D65. ..............................................................................................49 Figure 29. The relative responsivity of the d/30m instrument multiplied by the d/30m instrument illuminant compared to CIE D65 multiplied by the CIE color matching functions....................................................................................................50 Figure 30. The nighttime instrument averages of a range of entrance and observation angles. .......................................................................................................................51 Figure 31. The ratio between the cone of retroreflected light and diffusely scattered light changes with observation distance. ..................................................................51 Figure 32. The shift in the chromaticity coordinates for the angles corresponding to viewing distances of 10 m, 20 m, 30 m, 60 m, 75 m and 90 m along with the ASTM nighttime color boxes....................................................................................53 Figure 33. The shift in the chromaticity coordinates for a 30-m viewing geometry with actual distances of 3.65 m, 5 m, 10 m, 15 m, 20 m and 25 m along with the ASTM nighttime color boxes....................................................................................54 Figure 34. Shown is the comparison of the CHARRM measurements versus the nighttime instrument. ................................................................................................56 Figure 35. Spectral reflectance curves measured at NIST for three color chips. .......................99 Figure 36. The blue line is the spectral power distribution of the booth in D65 mode and the red line is the booth in Illuminant A mode multiplied by a factor of 50.............................................................................................................................101 Figure 37. Reflectance curves for 2.5 P9/2 and 10 Y8/10. ......................................................104 Figure 38. Transmission factor for the diffuser........................................................................105

viii Figure 39. The top surface reflectance of the diffuser is plotted versus wavelength. ..............106 Figure 40. Error plot for the response times as a function of response for chromaticity- 0...............................................................................................................................118 Figure 41. Error plot for the response times as a function of response for chromaticity- 1...............................................................................................................................119 Figure 42. Error plot for the response times as a function of response for chromaticity- 2...............................................................................................................................119 Figure 43. Error plot for the response times as a function of response for chromaticity- 3...............................................................................................................................120 Figure 44. Error plot for the response times as a function of response for chromaticity- 4...............................................................................................................................120 Figure 45. Error plot for the response times as a function of response for chromaticity- 5...............................................................................................................................121 Figure 46. Error plot for the response times as a function of response for chromaticity- 6...............................................................................................................................122 Figure 47. Error plot for the response times as a function of response for chromaticity- 7...............................................................................................................................122 Figure 48. Percentage of “yellow” responses for Ennis ThermoplasticY++ vs. Ennis Thermoplastic Y+ as a function of pavement marking location.............................125 Figure 49. Percentage of “yellow” responses for Ennis ThermoplasticY++ vs. Ennis Thermoplastic Y as a function of pavement marking location. ..............................127 Figure 50. Percentage of “yellow” responses for Ennis ThermoplasticY++ vs. Flint Trading Thermoplastic as a function of pavement marking location. ....................129 Figure 51. Percentage of “yellow” responses for Ennis ThermoplasticY++ vs. Latex Paint as a function of pavement marking location..................................................131 Figure 52. Percentage of “yellow” responses for Ennis ThermoplasticY++ vs. Latex Paint as a function of pavement marking location and headlamp type...................132 Figure 53. Percentage of “yellow” responses for Ennis ThermoplasticY+ vs. Ennis Thermoplastic Y as a function of pavement marking location. ..............................134 Figure 54. Percentage of “yellow” responses for Ennis Thermoplastic Y+ vs. Flint Trading Thermoplastic material as a function of pavement marking location. ......135 Figure 55. Percentage of “yellow” responses for Ennis ThermoplasticY+ vs. Latex Paint as a function of pavement marking location..................................................137 Figure 56. Percentage of combined “yellow” responses under HID and TH headlamp illumination for the combined data of the two materials Ennis Thermoplastic Y+ and Latex Paint as a function of pavement marking location...........................138 Figure 57. Percentage of “yellow” responses for Ennis ThermoplasticY+ vs. Latex Paint as a function of pavement marking location and headlamp type...................139

ix Figure 58. Percentage of “yellow” responses for Ennis Thermoplastic Y vs. Flint Trading Thermoplastic material as a function of pavement marking location. ......141 Figure 59. Percentage of “yellow” responses for Ennis Thermoplastic Y vs. Latex Paint type material as a function of pavement marking location. ....................................142 Figure 60. The percentage of yellow responses for the two headlamps as a function of pavement marking type...........................................................................................143 Figure 61. Percentage of “yellow” responses for Ennis Thermoplastic Y vs. Latex Paint as a function of pavement marking location and headlamp type............................144 Figure 62. Percentage of “yellow” responses for Flint Trading Thermoplastic vs. Latex Paint type material as a function of pavement marking location............................145 Figure 63. The percentage of yellow responses for the two headlamps as a function of pavement marking location for the combined data of the two materials Flint Trading Thermoplastic and Latex Paint..................................................................146

x LIST OF TABLES Table 1. Recommended 05-18 Nighttime Yellow Color Boundary ................................................8 Table 2. Recommended 05-18 Nighttime White Color Boundary ..................................................9 Table 3. Number of “yellow” and “white” responses for the variable “eccentricity”. ...........26 Table 4. Number of “yellow” and “white” responses for the variable “Road Surface Type”.........................................................................................................................26 Table 5. Number of “yellow” and “white” responses for the variable “Pavement Marking”. ..................................................................................................................26 Table 6. The color difference of the NIST scale minus the 0/45 instrument value. ...............43 Table 7. color difference of the NIST scale minus the nighttime instrument value. ..............44 Table 8. The CHARRM scale minus the nighttime instrument scale.....................................55 Table 9. Recommended 05-18 Nighttime Yellow Color Boundary ..............................................82 Table 10. Recommended 05-18 Nighttime White Color Boundary ..............................................83 Table 10. Agency Survey Results .............................................................................................86 Table 11. Color response data for Chromaticity 0. .................................................................108 Table 12. Color response data for Chromaticity 1. .................................................................108 Table 13. Color response data for Chromaticity 2. .................................................................110 Table 14. Color response data for Chromaticity 3. .................................................................111 Table 15. Color response data for Chromaticity 4. .................................................................112 Table 16. Color response data for Chromaticity 5. .................................................................113 Table 17. Color response data for Chromaticity 6. .................................................................114 Table 18. Color response data for Chromaticity 7. .................................................................115 Table 19. Number and percentage of “yellow” responses broken down into horizon sky luminance and road surface type categories.....................................................116 Table 20. Number and percentage of “yellow” responses broken down into pavement marking type and road surface type categories.......................................................116 Table 21. Number and percentage of “yellow” responses, broken down into road surface type and initial chromaticity condition combinations. ...............................117 Table 22. Number and percentage of “yellow” responses, broken down into pavement marking type and initial chromaticity condition combinations. .............................117 Table 23. GEE Analysis Summary for the Binary Data Obtained in the Field Experiment..............................................................................................................123 Table 24. GEE Summary Table for the Pairwise Comparison between Ennis ThemoplasticY++ vs. Ennis Thermoplastic Y+. ....................................................124

xi Table 25. GEE Summary Table for the Pairwise Comparison between Ennis ThemoplasticY++ vs. Ennis Thermoplastic Y........................................................125 Table 26. GEE Summary Table for the Pairwise Comparison between Ennis ThemoplasticY++ vs. Flint Trading Thermoplastic. ..............................................127 Table 27. GEE Summary Table for the Pairwise Comparison between Ennis ThemoplasticY++ vs. Latex Paint. .........................................................................129 Table 28. GEE Summary Table for the Pairwise Comparison between Ennis Themoplastic Y+ vs. Ennis Thermoplastic Y. ........................................................133 Table 29. GEE Summary Table for the Pairwise Comparison between Ennis ThemoplasticY+ vs. Flint Trading Thermoplastic..................................................134 Table 30. GEE Summary Table for the Pairwise Comparison between Ennis Themoplastic Y+ vs. Latex Paint............................................................................136 Table 31. GEE Summary Table for the Pairwise Comparison between Ennis Themoplastic Y vs. Flint Trading Thermoplastic ...................................................140 Table 32. GEE Summary Table for the Pairwise Comparison between Ennis Themoplastic Y vs. Latex Paint. .............................................................................141 Table 33. GEE Summary Table for the Pairwise Comparison between Flint Trading Thermoplastic vs. Latex Paint.................................................................................144

xii ACKNOWLEDGEMENTS This research project is sponsored by the National Cooperative Highway Research Program (NCHRP) of the Transportation Research Board (TRB) of the National Academy of Science, under the project designation NCHRP 5-18. We would also like to thank to Federal Highway Administration (FHWA) for providing field instruments. The authors would like to thank the NCHRP 5-18 panel members for their support, encouragement, and input in this project.