W. Riley Garrott

Measured Vehicle Inertial Parameters- NHTSA's Data Through November 1998

This chapter, from a comprehensive text on occupant and vehicle responses in rollovers, consists primarily of a printed listing of the National Highway Traffic Safety Administrations (NHTSA) Light Vehicle Inertial Parameter Database which cover 496 vehicles. Part one of the listing contains vehicle description and configuration data, plus wheelbase, track width, roof height, weight, and test comments. Part two contains vehicle description and configuration data, C.G. position, moments of inertia, roll/yaw products of inertia, tilt table ratio, and static stability factor data. The authors also offer a brief discussion of the accuracy of inertial measurements, including selected graphs of quantities listed in the database for some of the 1998 model year vehicles tested. Electronic copies of the Light Vehicle Inertial Parameter Database, which also contain Vehicle Identification Numbers (VIN) for the vehicles tested, may be obtained by contact Dr. W.R. Garrott (riley.garrott@nhtsa.dot.gov).

An Experimental Examination of J-Turn and Fishhook Maneuvers That May Induce On-Road, Untripped Light Vehicle Rollover

In this chapter, from a comprehensive text about occupant and vehicle responses in rollovers, the authors report on an experimental examination of J-turn and fishhook maneuvers that may induce on-road, untripped, light vehicle rollover. This chapter is the first of two papers on the research used to develop dynamic maneuver tests for rollover resistance ratings. This research was part of the National Highway Traffic Safety Administrations (NHTSA) rollover research program (2001). In this phase of research, five characterization maneuvers and eight rollover resistance maneuvers were evaluated and assigned a rating of Excellent, Good, Satisfactory, Bad, or Very Bad. This chapter offers an analysis of one characterization maneuver (the Slowly Increasing Steer maneuver) and four Rollover Resistance maneuvers (the NHTSA J-Turn, Fishhook 1a, Fishhook 1b, and Nissan fishhook). Results determined that each of these maneuvers has a rating of satisfactory or better in each of the maneuver evaluation factors (objectivity and repeatability, performability, discriminatory capability, and appearance of reality). The authors rated Fishhook 1b the best overall; however, since the NHTSA J-Turn is the most basic of potential maneuvers, they feel it serves as a useful complement to Fishhook 1b.

INITIAL DRIVER AVOIDANCE BEHAVIOR AND REACTION TIME TO AN UNALERTED INTERSECTION INCURSION.

Initial driver avoidance behavior and reaction time to an unexpected intersection incursion was determined using a state-of-the-art motion-based driving simulator (Iowa Driving Simulator). The intersection used for the experiment was on a two-lane rural highway (55 mph speed limit) that controlled perpendicular (crossing) traffic by stop signs. The subject vehicle did not have to stop and had the right-of-way on the highway. At one of three possible start times, an intersecting vehicle began moving into the intersection in front of the subject vehicle. This incurring vehicle intersected from either the drivers left or right side. Ninety-six subjects participated in the study. Subjects in the shortest, most severe collision avoidance situation were significantly slower to react and equally likely to steer or release the accelerator pedal as the initial avoidance maneuver. Subjects in the longest, least severe collision avoidance situation often released the accelerator pedal and braked prior to steering. Gender differences are also discussed.

Hardware evaluation of heavy truck side and rear object detection systems

This paper focuses on two types of electronics-based object detection systems for heavy truck applications: those sensing the presence of objects to the rear of the vehicle, and those sensing the presence of objects on the right side of the vehicle

An investigation, via simulation, of vehicle characteristics that contribute to steering maneuver induced rollover

In this chapter, from a comprehensive text about occupant and vehicle responses in rollovers, the authors report on research undertaken to find vehicle characteristics which may contribute to steering maneuver induced rollover accidents. The research used the Vehicle Dynamics Analysis, Non-Linear (VDANL) computer simulation on 28 different steering induced maneuvers for each of 51 vehicles; a total of 292 directional response metrics were computed for each vehicle. Results showed that the vehicle directional response metrics were not good predictors of the observed rollovers per single vehicle accident rate for each make/model of vehicle. Instead, two of the significant variables describe the accident location (whether or not the accident occurred in a rural area and whether or not the accident occurred on a curved section of roadway). The other four significant variables were not obtained from directional response simulation runs. They were: tilt table ratio, the number of single vehicle accidents per thousand registered vehicles, whether or not the vehicles had front wheel drive, and whether or not the vehicle was a sport utility vehicle. The authors conclude that none of the directional response metrics, alone, are good predictors of rollover propensities.

An Experimental Examination of Double Lane Change Maneuvers That May Induce On-Road, Untripped, Light Vehicle Rollover

This paper gives an account of the research used to develop maneuver tests for rollover resistance ratings. The paper discusses test procedures and results for five characterization maneuver and eight rollover resistance maneuvers. Each rollover resistance maneuver was evaluated based on its objectivity and reliability, performability, discriminatory capability, and appearance of reality. The objective of this paper was to obtain the data needed to select a limited set of maneuvers capable of assessing light vehicle rollover resistance.

Human Performance Evaluation of Heavy Truck Side Object Detection Systems

This study examines the effect of right Side Object Detection Systems ( SODS) on the performance of commercial vehicle drivers as a means of assessing the impact of these systems on safety. SODS are collision warning systems which alert drivers to the presence of traffic alongside their vehicle within defined detection zones.

Results from NHTSA's experimental examination of selected maneuvers that may induce on-road untripped, light vehicle rollover

A main goal of the National Highway Traffic Safety Administration (NHTSA) is to reduce the number of fatalities and injuries due to rollover crashes. To achieve this goal, the NHTSA is conducting research programs both to reduce the number of rollover crashes that occur and to mitigate the adverse consequences when rollover crashes do occur. To reduce the number of rollover crashes, the NHTSA is working to develop either an information program, which will make consumers more aware of vehicle makes/models with high rollover rates, or a Federal Motor Vehicle Safety Standard (FMVSS), which would prevent the manufacture of vehicles that have too high a rollover propensity, or both. One key step in the development of either a rollover propensity consumer information program or a rollover propensity FMVSS would be to construct a methodology for determining a vehicles rollover propensity. This study focuses on the development of such a methodology.

A Comprehensive Light Vehicle Antilock Brake System Test Track Performance Evaluation

To determine if situations and/or conditions exist in which ABS-equipped vehicles do not perform as well as those without ABS, the braking performance of nine passenger vehicles was observed over a comprehensive array of driving conditions. For most maneuvers, on most surfaces, ABS-assisted stops yielded distances shorter than those made with the ABS disabled. The one exception was on loose gravel where stopping distances increased by an average of 27.2 percent overall. Additionally, the vehicular stability observed during testing was almost always superior with ABS. For the cases in which instability was observed, ABS was not deemed responsible for its occurrence.

Human Factors Evaluation of Existing Side Collision Avoidance System Driver Interfaces

This paper presents an assessment of the driver interface component of side collision avoidance systems. It looks at the design of the interfaces, and recommendations are presented regarding ergonomically desirable or undesirable features. A preliminary set of driver interface performance specifications are listed.