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Lateral directional dynamic response properties and handling characteristics of All-Terrain Vehicles (ATVs) have been the subject of several investigations. Experimentally measured steady-state and transient handling response parameters of four ATVs are presented, reflecting two traditional automobile handling tests, the circle-turn and the J-turn test. Two three-wheel and two four-wheel ATVs were tested. One of the three-wheel and one of the four-wheel ATVs were equipped with conventional, but lockable differentials. The J-turn tests yielded transient response properties including lateral acceleration and yaw rate response times to step steer inputs, and steady-state response properties such as understeer coefficient, steering sensitivity and yaw response gain. ATV J-turn test results are compared to J-turn test results from selected automobiles.

As part of the National Highway Traffic Safety Administration’s (NHTSA) Light Vehicle Antilock Brake System (ABS) Research Program a study was conducted to examine driver crash avoidance behavior and the effects of ABS on drivers’ ability to avoid a collision in a crash-imminent situation. The test track study, described in detail in the SAE paper “Driver Crash Avoidance Behavior with ABS in an Intersection Incursion Scenario on Dry Versus Wet Pavement” [1], was designed to examine the effects of ABS versus conventional brakes, ABS brake pedal feedback level, and ABS instruction on driver behavior and crash avoidance performance. Exponent has obtained the electronic data collected by NHTSA in the dry pavement study and analyzed the steering inputs to better understand how drivers respond to emergency avoidance situations.

Testing techniques for creating rollovers have been a subject of much study and discussion, although previous work has concentrated on creating a repeatable laboratory test for evaluating and comparing vehicle designs. The two testing methodologies presented here address creating rollover tests that closely mimic a specific accident scenario, and are useful in accident reconstruction and evaluation of vehicle performance in specific situations. In order to be able to recreate accidents on off-road terrain, a test fixture called the Roller Coaster Dolly (RCD) was developed. With the RCD a vehicle can be released at speed onto flat or sloping terrain with any desired initial roll, pitch and yaw angle. This can be used to create rollover collisions from the trip stage on, including scenarios such as furrow trip on an inclined road edge.

Motorcycle stability during a variety of maneuvers is maintained through both rider steering input and body interactions with the seat, tank, footrests, and handlebars. Exploring how rider-vehicle interactions impact vehicle control is critical to creating a comprehensive understanding of motorcycle handling. The present study aims to understand how experienced motorcycle riders influence motorcycle dynamics by characterizing center of pressure (COP) location, force applied at the seat, rider lean angle and offset relative to the motorcycle, and steering angle for various maneuvers. A course was defined on Exponent’s Test and Engineering Center (TEC) track and skid pad that included sections of straight riding, navigating a banked curve, and sharp turning (low speed U-turns, 90 degree turn after a stop, and obstacle avoidance). The task influenced rider response and, in particular, lateral COP location at the seat.