Zone of Intrusion Envelopes Under MASH Impact Conditions for Rigid Barrier Attachments (2022)

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.

2022 N A T I O N A L C O O P E R A T I V E H I G H W A Y R E S E A R C H P R O G R A M NCHRP RESEARCH REPORT 1018 Zone of Intrusion Envelopes Under MASH Impact Conditions for Rigid Barrier Attachments Cody Stolle Jennifer Rasmussen Luis Rodriguez Robert Bielenberg Ronald Faller Nathan Dowler Midwest Roadside Safety Facility University of Nebraska-Lincoln Lincoln, NE Subscriber Categories Highways • Design • Safety and Human Factors Research sponsored by the American Association of State Highway and Transportation Ofcials in cooperation with the Federal Highway Administration

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 transporta- tion results in increasingly complex problems of wide interest to high- way 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 ini- tiated 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 Agree- ment No. 693JJ31950003. The Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine was requested by AASHTO to administer the research program because of TRB’s recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive com- mittee structure from which authorities on any highway transportation subject may be drawn; TRB possesses avenues of communications and cooperation with federal, state, and local governmental agencies, univer- sities, and industry; TRB’s relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of special- ists in highway transportation matters to bring the findings of research directly to those in a position to use them. The program is developed on the basis of research needs iden- tified by chief administrators and other staff of the highway and transportation departments, by committees of AASHTO, and by the FHWA. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&I’s recommendations are proposed to the AASHTO Board of Direc- tors and the National Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Academies and TRB. The needs for highway research are many, and NCHRP can make significant contributions to solving highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement, rather than to substitute for or duplicate, other highway research programs. Published research reports of the NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM are available from Transportation Research Board Business Office 500 Fifth Street, NW Washington, DC 20001 and can be ordered through the Internet by going to https://www.mytrb.org/MyTRB/Store/default.aspx Printed in the United States of America NCHRP RESEARCH REPORT 1018 Project 22-34 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-68751-5 Library of Congress Control Number 2022947651 © 2022 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trade- marks of the National Academy of Sciences. All rights reserved. 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, APTA, FAA, FHWA, FTA, GHSA, or NHTSA 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. NOTICE The research report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors. The Transportation Research Board does not develop, issue, or publish standards or speci- fications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications. The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturers’ names or logos appear herein solely because they are considered essential to the object of the report.

e 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. e 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. e 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. e 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. e 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. e Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. e 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. e 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. e 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 AUTHOR ACKNOWLEDGMENTS The research reported herein was performed under NCHRP Project 22-34 by the Midwest Roadside Safety Facility (MwRSF) at the University of Nebraska-Lincoln (UNL). Dr. Jennifer Rasmussen was the initial Project Director and Principal Investigator, but during the project, transferred leadership to Dr. Cody Stolle. Dr. Rasmussen completed her contributions to this project as co-Principal Investigator. The other authors of this report are Luis Rodriguez, M.S.M.E. and former MwRSF graduate research assistant; Robert (Bob) W. Bielenberg, Engineer II and chair of the MwRSF Pooled Fund Research Program; Dr. Ronald Faller, P.E., research full professor and MwRSF Director; and Nathan Dowler, M.S.M.E., former graduate research assistant. This work was completed utilizing the Holland Computing Center of the University of Nebraska, which receives support from the Nebraska Research Initiative. The authors would also like to acknowledge the staff of the Holland Computing Center for providing valuable support and guidance during the execution of the computer simulation suite. CRP STAFF FOR NCHRP RESEARCH REPORT 1018 Christopher J. Hedges, Director, Cooperative Research Programs Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program Sid Mohan, Associate Program Manager, Implementation and Technology Transfer, National Cooperative Highway Research Program Camille Crichton-Sumners, Senior Program Officer Traci Caldwell, Senior Program Assistant Natalie Barnes, Director of Publications Heather DiAngelis, Associate Director of Publications NCHRP PROJECT 22-34 PANEL Field of Design—Area of Vehicle Barrier Systems Ivy Y. Lane, ISL Engineering, Inc., West Linn, OR (Chair) Douglas J. Gabauer, Bucknell University, Lewisburg, PA Ali R. Hangul, Tennessee Department of Transportation, Nashville, TN Ahmed A. Ibrahim, University of Idaho, Moscow, ID James A. Mills, Pavement Analytics, LLC, Tallahassee, FL Derwood C. Sheppard, Jr., Florida Department of Transportation, Tallahassee, FL Eduardo Arispe, FHWA Liaison Kelly K. Hardy, AASHTO Liaison (continued on page vi)

NCHRP Research Report 1018: Zone of Intrusion Envelopes Under MASH Impact Condi- tions for Rigid Barrier Attachments provides state departments of transportation (DOTs) with updated zone of intrusion (ZOI) envelopes to account for crash impact events that estimate the bounds for the placement of roadside hardware appurtenances above or beyond the face of the barrier. The findings will be useful to practitioners responsible for roadway safety. Highway agencies often install safety countermeasures, such as pedestrian and bicycle railings, highway signage, high-protective screening fences, and luminaire poles, to the top or backside faces of crash-tested traffic barriers. These features may change the safety performance of the barrier systems. Thus, the ZOI concept was developed to help practition- ers address this issue. The ZOI is the area above and behind a barrier system that vehicle components may occupy during a crash impact event. ZOI envelopes provide parameters for the placement of roadside hardware appurtenances above or beyond the face of the barrier. Factors influencing the ZOI include the type of vehicle, crash speed, impact angle, and barrier geometry. Current ZOI guidance in the 4th edition of the AASHTO Roadside Design Guide was developed based on old crash testing standards. Under NCHRP Project 22-34, “Determination of Zone of Intrusion Envelopes under MASH Impact Conditions for Barrier Attachments,” the Midwest Roadside Safety Facility was asked to develop ZOI envelopes for a variety of rigid barriers under the Manual for Assessing Safety Hardware (MASH) criteria and guidance for state transportation agency practitioners along with documentation for consideration by AASHTO for inclusion in the Roadside Design Guide. NCHRP Research Report 1018 provides an updated, practical means to determine the ZOI and is intended for practitioners in state DOTs and local municipalities involved in the design and installation of roadside safety systems. The appendices (not included herein) and a presentation documenting the research process are available by searching on NCHRP Research Report 1018: Zone of Intrusion Envelopes Under MASH Impact Conditions for Rigid Barrier Attachments on the National Academies Press website (www.nap.edu). F O R E W O R D By Camille Crichton-Sumners Staff Officer Transportation Research Board

AUTHOR ACKNOWLEDGMENTS (Continued) The authors wish to acknowledge several sources that contributed to this project. First, the authors appreciate the contributions from the Texas A&M Transportation Institute, specifically Nauman Sheikh, Akram Odeh, Roger Bligh, and Lance Bullard for providing full-scale crash test video footage critical to the development of zone of influence envelopes and additional crash test data used to validate vehicle models. The authors also wish to acknowledge Chuck Plaxico and Roadsafe LLC for providing heavy truck models for evaluation. Finally, the authors want to specifically acknowledge current and former MwRSF personnel, including Harry Nguyen, Alex Russell, Nathan Asselin, Christopher Storf, Miguel Hinojosa, and Jacob DeLone for contributions to vehicle models, data collection, and summarization. Acknowledgment is also given to the following individuals who contributed to the completion of this research project. Midwest Roadside Safety Facility J.D. Reid, Ph.D., Professor (Retired) J.C. Holloway, M.S.C.E., Research Engineer and Assistant Director – Physical Testing Division K.A. Lechtenberg, M.S.M.E., Research Engineer S.K. Rosenbaugh, M.S.C.E., Research Engineer M. Asadollahi Pajouh, Ph.D., P.E., Research Assistant Professor A.T. Russell, B.S.B.A., Testing and Maintenance Technician II E.W. Krier, B.S., Construction and Testing Technician II S.M. Tighe, Construction and Testing Technician I D.S. Charroin, Construction and Testing Technician I R.M. Novak, Construction and Testing Technician I T.C. Donahoo, Construction and Testing Technician I J.T. Jones, Construction and Testing Technician I E.L. Urbank, B.A., Research Communication Specialist

1 Summary 3 Chapter 1 Introduction 3 1.1 Background 8 1.2 Research Objective 8 1.3 Research Scope 9 Chapter 2 Literature Review and Survey 9 2.1 ZOI Background and Development 12 2.2 Rigid Barrier Types 15 2.3 Minimum Barrier Height 16 2.3.1 MASH TL-2 16 2.3.2 MASH TL-3 17 2.3.3 MASH TL-4 20 2.3.4 MASH TL-5 21 2.4 Existing Rigid Barrier Simulations 27 2.5 In-Service Performance Data 27 2.5.1 Research Reports 28 2.5.2 Case Studies 31 2.5.3 Summary 31 2.6 Review of State DOT Standard Plans 32 2.7 Agency Survey 32 2.7.1 Overview 32 2.7.2 Discussion 33 2.8 Barrier Height Thresholds 33 2.8.1 MASH TL-2 33 2.8.2 MASH TL-3 34 2.8.3 MASH TL-4 34 2.8.4 MASH TL-5 35 Chapter 3 Rigid Barrier Crash Data Analysis 35 3.1 Rigid Barrier Crash Test Database 35 3.2 ZOI Measurement from Video 38 3.3 Preliminary ZOI Envelopes 39 3.4 Investigation of Vehicle and Rigid Barrier Interaction 39 3.4.1 Vehicle-Barrier Friction 40 3.4.2 Quarter Panel Crush Stiffness 41 3.4.3 Suspension Joint Strength and Failure Time 41 3.4.4 Vehicle Properties 44 3.4.5 Summary C O N T E N T S

45 Chapter 4 Simulation Calibration 45 4.1 Overview 45 4.2 Model Preparation 46 4.2.1 Vehicle Model Refinements 47 4.2.2 Evaluation Criteria 47 4.3 ZOI Measurement Procedure 48 4.4 Vehicle Model Calibration 48 4.4.1 RAM 49 4.4.2 F800 SUT 51 4.4.3 Tractor-Trailer 53 4.5 Summary of Calibrated Simulation Parameters 54 Chapter 5 Simulated ZOI Envelopes 54 5.1 Simulation Suite and Data Collection 54 5.1.1 Barrier Geometries 54 5.1.2 Barrier Mesh Sizes 54 5.1.3 ZOI Envelope Development 57 5.2 Concepts for Representing ZOI Envelopes 57 5.2.1 MASH TL-2 and TL-3 59 5.2.2 MASH TL-4 and TL-5 60 5.3 ZOI Envelope Simulation Results 60 5.3.1 MASH TL-2 67 5.3.2 MASH TL-3 73 5.3.3 MASH TL-4 84 5.3.4 MASH TL-5 94 5.4 Validation of ZOI Envelopes 94 5.4.1 Overview 96 5.4.2 MASH TL-2 100 5.4.3 MASH TL-3 100 5.4.4 MASH TL-4 109 5.4.5 MASH TL-5 118 Chapter 6 Recommended ZOI Envelopes 118 6.1 Determination of ZOI Envelope Dimensions 119 6.2 MASH TL-2 119 6.3 MASH TL-3 119 6.4 MASH TL-4 122 6.5 MASH TL-5 122 6.6 Discussion 130 Chapter 7 Future Research Needs 130 7.1 Median Barrier Sign Supports and Poles 130 7.2 Bridge Pier Protection 130 7.3 Guidelines for Mechanically Stabilized Earth (MSE) Walls 131 7.4 Noise Walls and Structural Barrier Attachments 131 7.5 Pedestrian Protection 131 7.6 MASH TL-6 Truck-Tank Trailer Combination Vehicle ZOI Guidelines 131 7.7 In-Service Performance Evaluations (ISPEs)

133 Chapter 8 Test Documentation and Modeling Improvements Recommendations 133 8.1 Overview 133 8.2 ZOI Measurements and Working Width 133 8.3 Camera Positioning for ZOI Measurement 135 8.4 View Calibration and Documentation Improvements 136 8.5 Large Truck Documentation Improvements 136 8.5.1 10000S Documentation 137 8.5.2 Tractor-Trailer Documentation 137 8.6 Considerations for Future ZOI Studies 138 8.7 RAM Model Improvements 138 8.7.1 Steering Mechanics 140 8.7.2 Front-End Connections 140 8.8 SUT Model Improvements 140 8.8.1 Vehicle Model Comparison to Test Vehicles 142 8.8.2 Mesh Density 143 8.8.3 U-Bolt Failure and Suspension Modeling 143 8.9 Tractor-Trailer Model Improvements 147 Chapter 9 Summary, Conclusions, and Recommendations 147 9.1 Summary 147 9.1.1 Background Data Collection 148 9.1.2 Agency Survey 148 9.1.3 Preliminary ZOI Envelopes 148 9.1.4 FEA Computer Simulation 149 9.1.5 Development of ZOI Envelope Recommendations 150 9.2 Conclusions 150 9.3 Recommendations 153 References