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Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2021. Principles and Guidance for Presenting Active Traffic Management Information to Drivers. Washington, DC: The National Academies Press. doi: 10.17226/25994.
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NCHRP Web-Only Document 286: Principles and Guidance for Presenting Drivers with Dynamic Information on Active Traffic Management Joonbum Lee Christian M. Richard John L. Campbell James L. Brown Liberty Hoekstra-Atwood Kelly Magee David M. Prendez Battelle Columbus, OH Jeremy L. Schroeder Athey Creek Consultants Tacoma, WA Contractor’s Final Report for NCHRP Project 03-124 Submitted February 2021 NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state departments of transportation (DOTs) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 initiated an objective national highway research program using modern scientific techniques—the National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration (FHWA), United States Department of Transportation, under Agreement No. 693JJ31950003. COPYRIGHT INFORMATION 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, FTA, GHSA, NHTSA, or TDC 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 opinions and conclusions expressed or implied in this report are those of the researchers who performed the research. They are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors. The information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, non- governmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. John L. Anderson is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.nationalacademies.org. The Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to provide leadership in transportation improvements and innovation through trusted, timely, impartial, and evidence-based information exchange, research, and advice regarding all modes of transportation. The Board’s varied activities annually engage about 8,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state transportation departments, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation. Learn more about the Transportation Research Board at www.TRB.org.

C O O P E R A T I V E R E S E A R C H P R O G R A M S CRP STAFF FOR NCHRP WEB-ONLY DOCUMENT 286 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs B. Ray Derr, Senior Program Officer Anthony Avery, Senior Program Assistant Eileen P. Delaney, Director of Publications Natalie Barnes, Associate Director of Publications Jennifer Correro, Assistant Editor NCHRP PROJECT 03-124 PANEL Field of Traffic—Area of Operations and Control Gene S. Donaldson, Delaware Department of Transportation, Smyrna, DE (Chair) Ingrid L. Birenbaum, Moffat & Nichol, Fort Lauderdale, FL Joel Cooper, Red Scientific Inc, Salt Lake, UT Neal R. Hawkins, Iowa State University, Ames, IA Reza Karimvand, Arizona Department of Transportation, Phoenix, AZ Mubeen S. Quadri, Ohio Department of Transportation, Columbus, OH Brian Philips, FHWA Liaison Richard A. Cunard, TRB Liaison

i Table of Contents Chapter 1: Introduction ......................................................................................................................... 1 Chapter 2: State of the Practice .......................................................................................................... 3 Use of Symbols in ATM Deployments and the MUTCD ........................................................................ 3 Multipurpose Overhead Lane Use Control Sign Deployments ......................................................... 5 Dynamic Lane Control and Dynamic Lane Reversal .......................................................................... 13 Dynamic Shoulder Lane Deployments .................................................................................................... 14 Dynamic Speed Limit Deployments .......................................................................................................... 18 Dynamic Junction Control Deployments ................................................................................................ 27 Dynamic Merge Control Deployments ..................................................................................................... 28 Dynamic Queue Warning Deployments .................................................................................................. 28 Static Signage in Advance of ATM Deployments ................................................................................. 30 International ATM Deployments ............................................................................................................... 32 In-Vehicle ATM Messaging ........................................................................................................................... 33 Chapter 3: Literature Review ........................................................................................................... 36 Methods for the Literature Search ............................................................................................................ 36 Literature Synthesis ........................................................................................................................................ 38 Conclusions ......................................................................................................................................................... 40 Chapter 4: Research Gaps .................................................................................................................. 41 Overview .............................................................................................................................................................. 42 Research Gap Descriptions ........................................................................................................................... 42 Conclusions ......................................................................................................................................................... 47 Chapter 5: Empirical Studies ............................................................................................................ 48 General Approach to Experiments 1 and 2 ............................................................................................ 49 Participants ................................................................................................................................................... 49 Apparatus: Battelle MiniSim™ Simulator .......................................................................................... 50 Apparatus: In-Vehicle ATM Device’s Interface and Operation ................................................. 50 Eye Tracker .................................................................................................................................................... 52 Experimental Design ................................................................................................................................. 53 Procedure ....................................................................................................................................................... 54 Experiment 1: Evaluating the Effects of Information Availability of Dynamic Lane Control on Driver Behavior and Distraction .............................................................................. 55 Overview ......................................................................................................................................................... 55 Methods........................................................................................................................................................... 57 Results ............................................................................................................................................................. 60 Discussion ...................................................................................................................................................... 72 Experiment 2: Evaluating the Effects of Information Modality and Information Type of Dynamic Speed Limit Displays on Driver Behavior and Distraction. ......................... 75 Overview ......................................................................................................................................................... 75 Methods........................................................................................................................................................... 76 Results ............................................................................................................................................................. 79 Discussion ...................................................................................................................................................... 90 Experiment 3: Examining How Agencies Approach the Deployment and Evaluation of ATM Applications. ................................................................................................................ 92 Overview ......................................................................................................................................................... 92 Results ............................................................................................................................................................. 93 Objectives for the Study ........................................................................................................................... 94

ii Chapter 6: Conclusions ..................................................................................................................... 101 Appendices ........................................................................................................................................... 106 Appendix A: Full Interview Responses & Follow-Up Survey Results ...................................... 107 Full Interview Responses ..................................................................................................................... 107 Follow-Up Survey Results .................................................................................................................... 132 Appendix B: List of Data Sources Given In-Depth Reviews ......................................................... 139 Appendix C: Research Question Evaluation Survey ........................................................................ 141 Appendix D: Research Gap Consensus Scores and Notes ............................................................. 147 Appendix E: References .............................................................................................................................. 150

iii List of Tables Table 1. Overhead dynamic lane control signage deployments and accompanying strategies in the United States. ..................................................................................................................................... 7 Table 2. Current and planned dynamic shoulder lane deployments in the United States. ......................... 15 Table 3. Current, planned, and discontinued dynamic speed limit deployments in the United States. ........................................................................................................................................................ 20 Table 4. Urban and congestion dynamic speed limit deployments in the United States. ........................... 23 Table 5. Weather dynamic speed limit deployments in the United States. ....................................................... 25 Table 6. Select dynamic speed limit deployments in work zones. ........................................................................ 26 Table 7. Temporary dynamic queue warning system deployments in the United States. ......................... 29 Table 8. International ATM strategy deployments....................................................................................................... 32 Table 9. Research synthesis matrix. .................................................................................................................................... 41 Table 10. Definitions for rating within the three scales. ............................................................................................ 45 Table 11. List of the key research questions and corresponding research gaps. ........................................... 46 Table 12. Final scores for the 13 research gaps. ........................................................................................................... 46 Table 13. Overview of the three experiments and research gaps. ........................................................................ 48 Table 14. Data sources for addressing research gaps in Experiment 1. ............................................................ 56 Table 15. Sources of ATM information for each experimental condition. ......................................................... 57 Table 16. Data sources for addressing gaps in Experiment 2. ................................................................................ 76 Table 17. Sources of ATM information, information modality, and availability of prescriptive warning for each experimental condition. ........................................................................................................... 77 Table 18. Stakeholders interviewed for Experiment 3. .............................................................................................. 93 Table 19. Deployment of ATM strategies among respondents’ agencies. .......................................................... 97 List of Figures Figure 1. Project sequence and tasks. ................................................................................................................................... 2 Figure 2. ATM lane control displays used by different deployment sites to convey information to drivers (WSDOT, MnDOT, CDOT, Caltrans, VDOT). ............................................................................................. 4 Figure 3. Dynamic speed limit signs in Maine, left, and Oregon, right (MaineDOT, Oregon DOT). ............ 5 Figure 4. Lane use control signage on US 36 in Denver (Google Maps). ................................................................ 8 Figure 5. Lane use control signage on I-25 southbound in Denver (Google Maps). ......................................... 8 Figure 6. Lane use control signage on the I-295 Delaware Memorial Bridge (Google Maps). ..................... 9 Figure 7. Lane use control signage on the I-90 Tollway northwest of Chicago (Google Maps)................... 9 Figure 8. Lane use control signage on I-93 in Boston (Google Maps). .................................................................... 9 Figure 9. Lane use control signage on I-35W in Minneapolis (Google Maps). ................................................. 10 Figure 10. Lane use control signage on US 290 in Austin (Google Maps). ......................................................... 10 Figure 11. Lane use control signage on I-66 in Northern Virginia (VDOT). ...................................................... 11 Figure 12. Lane use control signage on I-66 in Northern Virginia (VDOT). ...................................................... 11 Figure 13. Lane use control signage on I-5 in Seattle (Google Maps). ................................................................. 12 Figure 14. Lane use control signage on I-5 in Seattle (WSDOT). ........................................................................... 12 Figure 15. Arterial lane control signs on 5400 South in Taylorsville, Utah (Google Maps). ..................... 13 Figure 16. Arterial lane control signs in Montgomery County, Maryland (Google Maps). ......................... 13 Figure 17. Lane reversal deployment on I-595 HOT Lanes in Miami (Google Maps). ................................. 14 Figure 18. Lane reversal deployment on I-5 HOV Lanes in Seattle (Google Maps). ...................................... 14 Figure 19. Dynamic shoulder lane on I-70 East in Colorado (Google Maps). ................................................... 14 Figure 20. Dynamic shoulder lane on I-85 North near Atlanta (Google Maps). .............................................. 15 Figure 21. Dynamic shoulder lane on I-35W North in Minneapolis (MnDOT). ............................................... 16 Figure 22. Dynamic shoulder lane on the I-78 New Jersey Turnpike in Newark (FHWA). ........................ 16 Figure 23. Dynamic shoulder lane on I-66 in Northern Virginia (Google Maps). ........................................... 17 Figure 24. Previous static time of day shoulder lane on I-66 in Northern Virginia (FHWA). ................... 17

iv Figure 25. Dynamic shoulder lane on I-495 North in Northern Virginia (Google Maps). ........................... 18 Figure 26. Dynamic junction control on the SR 110 Arroyo Seco Parkway in Los Angeles (Caltrans). ................................................................................................................................................. 27 Figure 27. Dynamic junction control on I-94 in Minneapolis displaying guide signs for an exit with and without an exit only lane designation (Google Maps). .......................................... 27 Figure 28. Dynamic merge control to encourage a late merge at a work zone in Minnesota (MnDOT). ...................................................................................................................................................... 28 Figure 29. Typical, temporary dynamic queue warning system deployed for a work zone on I-35 in central Texas (Texas A&M Transportation Institute). .................................................... 30 Figure 30. Static sign in advance of dynamic speed limits on SR 520 in Seattle (Google Maps). ............ 31 Figure 31. Static sign in advance of dynamic speed limits on I-270 in St. Louis (Courtesy of Missouri Department of Transportation) .................................................................................. 31 Figure 32. Static sign to explain former dynamic shoulder lane symbols and hours on I-66 in Northern Virginia (FHWA). ......................................................................................................................................... 31 Figure 33. Static sign to explain lane control symbols currently in use on I-66 in Northern Virginia (VDOT). .......................................................................................................................................... 31 Figure 34. Static sign to explain dynamic shoulder lane symbols on I-495 in Northern Virginia (Google Maps). ................................................................................................................................................ 32 Figure 35. Static sign to explain dynamic shoulder lane symbols on I-85 near Atlanta (Google Maps). .................................................................................................................................................. 32 Figure 36. Example of an ATM deployment in the United Kingdom (Capita Real Estate and Infrastructure) .................................................................................................................................................................. 33 Figure 37. In-vehicle display for INC-ZONE dynamic merge control and dynamic speed limit applications during closed field test demonstration in Maryland (Battelle). ....................................... 35 Figure 38. In-vehicle display for INFLO dynamic queue warning and dynamic speed limit applications during demonstration test in Seattle on I-5 north (Battelle). ................................ 35 Figure 39. A smartphone was used as an in-vehicle display of information during the INC-ZONE and INFLO demonstrations (Battelle).............................................................................................. 35 Figure 40. Overview of Literature Review Activities. ................................................................................................. 36 Figure 41. Sample Document Summary Template (adapted from McCallum et al., 2006). ....................... 38 Figure 42. Final scores of the 13 research gaps in three dimensions (color represents expected methods to conduct studies). ................................................................................................................. 47 Figure 43. The smartphone was located to the right of the steering wheel (Battelle). ................................ 51 Figure 44. A screen capture from the smartphone application (Battelle). ........................................................ 52 Figure 45. Ergoneers head-mounted eye-tracker. ........................................................................................................ 53 Figure 46. Manually defined AOI (blue box) and drivers’ fixation point (red crossed circle) captured from the D-Lab software. ......................................................................................................................... 53 Figure 47. Road layout for Experiment 1. ........................................................................................................................ 58 Figure 48. Lane signal symbols. ............................................................................................................................................ 59 Figure 49. A sample image of overhead gantry with lane closure signs from Experiment 1 (Battelle). ............................................................................................................................................... 59 Figure 50. Provisional signs (highlighted in red boxes) from Experiment 1 (Battelle). .............................. 59 Figure 51. Percentage of time spent complying with lane closures. .................................................................... 60 Figure 52. Percentage of time in merge/close lanes. .................................................................................................. 61 Figure 53. Glance measurement summary statistics for Experiment 1. ............................................................. 62 Figure 54. Total glance time to the smartphone in seconds. ................................................................................... 63 Figure 55. Mean glance time to the smartphone in seconds. ................................................................................... 64 Figure 56. Ratings for importance of each ATM application’s purpose. ............................................................. 65 Figure 57. Ratings for usefulness of each ATM application. ..................................................................................... 65 Figure 58. Ratings for how well each ATM application communicates. ............................................................. 65 Figure 59. Ratings for level of comprehension of symbols used in each ATM application. ....................... 66 Figure 60. Usefulness ratings for overhead mounted sign and smartphone ATM applications. ............. 66 Figure 61. Preference ratings for overhead mounted signs and smartphone ATM applications. ........... 67 Figure 62. Preference ratings for all ATM applications.............................................................................................. 67 Figure 63. Preference rating for each ATM presentation mode. ............................................................................ 68

v Figure 64. Participants’ timing assessment of the smartphone application in just-in-time mode. ........ 68 Figure 65. Boxplots of participants responses on their strategy to use both ATM media. ......................... 69 Figure 66. Distraction ratings for sign presentation by smartphone application mode. ............................ 69 Figure 67. Annoyance ratings for sign presentation by smartphone application mode. ............................ 70 Figure 68. Overall distraction ratings for smartphone application. ..................................................................... 70 Figure 69. Participants’ self-reported likeliness to use the smartphone application to receive ATM information in the future. ............................................................................................................ 70 Figure 70. Percentage of participants who noticed reduced speed zone sign. ................................................ 70 Figure 71. Participants’ self-reported effectiveness of the provisional signs. ................................................. 71 Figure 72. Examples of provisional signs presented to participants (Battelle). ............................................. 71 Figure 73. Importance ratings for provisional signs. .................................................................................................. 72 Figure 74. Effectiveness ratings for provisional signs. ............................................................................................... 72 Figure 75. Ease of understanding ratings for provisional signs. ............................................................................ 72 Figure 76. Road layout for Experiment 2 (Battelle). ................................................................................................... 78 Figure 77. Sample image of dynamic speed limit information presented on gantries for Experiment 2 (Battelle). ............................................................................................................................................... 79 Figure 78. Percentage of speed compliance and average speed exceedance (delta speed) by experimental condition. ......................................................................................................................................... 79 Figure 79. Percentage of speed compliance. ................................................................................................................... 80 Figure 80. Speed exceedance. ................................................................................................................................................ 81 Figure 81. Summary glance statistics for Experiment 2. ........................................................................................... 81 Figure 82. Total glance time to the smartphone across experimental conditions. ........................................ 83 Figure 83. Mean glance time to smartphone across experimental conditions. ............................................... 84 Figure 84. Participants’ subjective ratings of effectiveness for three types of ATM media. ...................... 85 Figure 85. Participants’ ratings for how well three types of ATM media communicate. ............................ 86 Figure 86. Participants’ relative ratings of effectiveness for three ATM media by road type. ................. 87 Figure 87. Participants’ relative ratings of effectiveness for five ATM strategies by road type. ............. 87 Figure 88. Participants’ ratings for usefulness and preference between overhead signs and smartphone application as ATM media. ................................................................................................................ 88 Figure 89. Participants’ comparisons of the three ATM presentation modes in Experiment 2. .............. 89 Figure 90. Distraction ratings for the three smartphone application modes in Experiment 2. ............... 89 Figure 91. Participants’ preferred way to receive navigation instructions. ...................................................... 90 Figure 92. Participants’ self-reported likeliness to use the smartphone application to receive ATM information in the future. ................................................................................................................. 90

vi List of Acronyms and Abbreviations AASHTO ................ American Association of State Highway and Transportation Officials ADT ................................................................................................... Average Daily Traffic ATIS ....................................................................... Advanced Traveler Information System BES ................................................................................................ Best Evidence Synthesis CMS ............................................................................................ Changeable Message Sign CR ................................................................................................................. Contrast Ratios DOT ....................................................................................... Department of Transportation HFG............................................................................................. Human Factors Guidelines HPS ................................................................................................... High-Pressure Sodium IHSDM ............................................................... Interactive Highway Safety Design Model LCS ......................................................................................................Lane Control Signals LED ..................................................................................................... Light Emitting Diode MUTCD ......................................................... Manual on Uniform Traffic Control Devices NCHRP ................................................. National Cooperative Highway Research Program NLT .................................................................................................................. No Left Turn NRT................................................................................................................ No Right Turn PCC ............................................................................................. Portland Cement Concrete PCMS ............................................................................ Portable Changeable Message Sign RRPM ........................................................................ Raised Reflective Pavement Marking RSI ............................................................................... Level of Reported Sign Information RT .................................................................................................................. Reaction Time SAFETEA-LU .................................. Safe, Accountable, Flexible, Efficient Transportation Equity Act: Legacy for Users SRS ................................................................................................... Shoulder Rumble Strip SUV...................................................................................................... Sport Utility Vehicle SVB ......................................................................................................... Slow Vehicle Bays SVROR ..................................................................................Single Vehicle Run-Off-Road SYG..................................................................................................... Strong Yellow-Green TIM ....................................................................................... Tactical Incident Management TTC ........................................................................................................... Time-to-Collision VMS ................................................................................................ Variable Message Signs VPD............................................................................................................ Vehicles per Day VSL ..................................................................................................... Variable Speed Limit USSC.......................................................................................... United States Sign Council

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Active Traffic Management (ATM) strategies have become more common in the United States as state departments of transportation grapple with increasing congestion and fewer dollars available to add capacity to keep pace.

The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 286: Principles and Guidance for Presenting Active Traffic Management Information to Drivers develops and details principles and guidance for presenting drivers with dynamic information that can be frequently updated based on real-time conditions.

These principles and guidance should improve the effectiveness of ATM strategies, which include systems to manage congestion, incidents, weather, special events, and work zones.

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