US Department of Transportation National Highway Traffic Safety Administration DOT HS 809 547 October 2003 An Experimental Evaluation of 26 Light Vehicles Using Test Maneuvers That May Induce On-Road, Untripped Rollover and a Discussion of NHTSA’s Refined Test Procedures Phases VI and VII of NHTSA’s Light Vehicle Rollover Research Program Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT HS 809 547 4. Title and Subtitle 5. Report Date An Experimental Examination of 26 Light Vehicles Using Test Maneuvers That May October 2003 Induce On-Road, Untripped Rollover and a Discussion of NHTSA’s Refined Test 6. Performing Organization Code Procedures - Phases VI and VII of NHTSA’s Light Vehicle Rollover Research Program NHTSA/NVS-312 7. Author(s) 8. Performing Organization Report No. Garrick J. Forkenbrock, NHTSA Bryan C. O’Harra and Devin Elsasser, Transportation Research Center Inc. 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) National Highway Traffic Safety Administration Vehicle Research and Test Center 11. Contract or Grant No. P.O. Box 37 East Liberty, OH 43319 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered National Highway Traffic Safety Administration Final Report 400 Seventh Street, S.W. 14. Sponsoring Agency Code Washington, D.C. 20590 15. Supplementary Notes 16. Abstract The National Highway Traffic Safety Administration (NHTSA) has been researching the area of light vehicle dynamic rollover resistance for nearly thirty years. In the past, repeatability, performability, and discriminatory capability issues compromised maneuvers that endeavored to assess rollover resistance. It was not until recently that NHTSA was able to isolate maneuvers capable of resolving such issues. This report discusses Phases VI and VII of NHTSA’s 2001 -2002 Light Vehicle Rollover Research Program. Phase VI was intended to be a comprehensive evaluation of many vehicles, using maneuvers and procedures developed during Phases IV and V. In Phase VI, performed during the spring through fall of 2002, the rollover resistances of a broad range of 26 light vehicles were assessed. The test vehicles were evaluated with one Characterization maneuver and two Rollover Resistance maneuvers, with up to two load configurations per vehicle. The Phase VI vehicle fleet was comprised of nine sport utility vehicles (SUVs), six pick-ups, five minivans, and six passenger cars, selected by vehicle classification, known single-vehicle rollover accident data, and static stability factor (SSF). A detailed description of the testing and results is presented. For the Rollover Resistance maneuvers, two-wheel lift is summarized and its repeatability discussed. Of the 26 vehicles tested, ten produced two -wheel lift. Phase VII was intended to improve and revise the maneuvers and procedures used in Phase VI. In Phase VII, a “Multi- Passenger” load configuration was defined (a revised version of the Maximum Occupancy configuration used in Phase VI), a means of reporting the occurrence of rim-to-pavement contact and/or debeading was discussed, and the concept of adjusting handwheel angles via scalars to improve rollover resistance maneuver severity was explored. The Multi- Passenger configuration used up to three water dummies placed in rear seating positions. This differed from the Maximum Occupancy configuration in that not in every rear seating position was occupied. Phase VII results indicate the Multi-Passenger loading may be less severe than the Maximum Occupancy configuration for some vehicles, but its use will retain NHTSA’s ability to evaluate the rollover resistance of vehicles at two severity levels with higher face validity. Phase VII results indicate steering scalar reductions can improve maneuver severity in cases where steering inputs are so large they saturated the vehicles’ tires; the authors recommend revising the test procedure of each maneuver to reflect the reduction of the steering scalars. The authors recommend that a test series be terminated if ri m-to-pavement contact is observed, and that this information be included as a supplement to the vehicle’s NCAP Rollover Rating. 17. Key Words 18. Distribution Statement Rollover, Dynamic Testing, J-Turn, Road Edge Recovery, Fishhook, Document is available to the public from TREAD Act The National Technical Information Service Springfield, VA 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified Form DOT F 1700.7 (8-72) Reproduction of completed page authorized i CONVERSION FACTORS Approximate Conversions to Metric Measures Approximate Conversions to English Measures Symbol When You Know Multiply by To Find Symbol Symbol When You Know Multiply by To Find Symbol LENGTH LENGTH in inches 25.4 millimeters mm mm millimeters 0.04 inches in in inches 2.54 centimeters cm cm centimeters 0.39 inches in ft feet 30.48 centimeters cm m meters 3.3 feet ft mi miles 1.61 kilometers km km kilometers 0.62 miles mi AREA AREA in2 square inches 6.45 square centimeters cm2 cm2 square centimeters 0.16 square inches in2 ft2 square feet 0.09 square meters m2 m2 square meters 10.76 square feet ft 2 mi2 square miles 2.59 square kilometers km2 km2 square kilometers 0.39 square miles mi2 ii MASS (weight) MASS (weight) oz ounces 28.35 grams g g grams 0.035 ounces oz lb pounds 0.45 kilograms kg kg kilograms 2.2 pounds lb PRESSURE PRESSURE psi pounds per inch2 0.07 bar bar bar bar 14.50 pounds per inch2 psi psi pounds per inch2 6.89 kilopascals kPa kPa kilopascals 0.145 pounds per inch2 psi VELOCITY VELOCITY mph miles per hour 1.61 kilometers per hour km/h km/h kilometers per hour 0.62 miles per hour mph ACCELERATION ACCELERATION ft/s 2 feet per second2 0.30 meters per second2 m/s 2 m/s 2 meters per second2 3.28 feet per second2 ft/s 2 TEMPERATURE (exact) TEMPERATURE (exact) �F Fahrenheit 5/9 (Celsius) - 32�C Celsius �C �C Celsius 9/5 (Celsius) + 32�F Fahrenheit �F DISCLAIMER This publication is distributed by the U.S. Department of Transportation, National Highway Traffic Safety Administration, in the interest of information exchange. The opinions, findings, and conclusions expressed in this publication are those of the author(s) and not necessarily those of the Department of Transportation or the National Highway Traffic Safety Administration. The United States Government assumes no liability for its contents or use thereof. If trade or manufacturers= names or products are mentioned, it is because they are considered essential to the object of the publication and should not be construed as an endorsement. The United States Government does not endorse products or manufacturers. iii NOTE REGARDING COMPLIANCE WITH AMERICANS WITH DISABILITIES ACT SECTION 508 For the convenience of visually impaired readers of this report using text-to-speech software, additional descriptive text has been provided for graphical images contained in this report to satisfy Section 508 of the Americans With Disabilities Act (ADA). iv TABLE OF CONTENTS TECHNICAL REPORT DOCUMENTATION PAGE........................................................................................................ i METRIC CONVERSION FACTORS .....................................................................................................................................ii DISCLAIMER ...............................................................................................................................................................................iii NOTE REGARDING COMPLIANCE WITH AMERICANS WITH DISABILITIES ACT SECTION 508.................................................................................................................................................................................iv TABLE OF CONTENTS ..............................................................................................................................................................v LIST OF FIGURES ...................................................................................................................................................................viii LIST OF TABLES ..........................................................................................................................................................................x ACKNOWLEDGEMENTS ......................................................................................................................................................xii EXECUTIVE SUMMARY ......................................................................................................................................................xiii 1.0 INTRODUCTION................................................................................................................................................................. 1 1.1 Scope of This Investigation.....................................................................................................................................1 1.2 Consumer Information on Rollover Resistance...................................................................................................2 1.3 Rollover Resistance Requirements of the TREAD Act .....................................................................................3 1.4 NHTSA’s 2001-02 Rollover Research Program.................................................................................................3 1.4.1 Phase IV: Maneuver Selection and Procedure