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Vehicle front-end geometry and stiffness characteristics have been shown to influence pedestrian lower extremity response and injury patterns. The goal of this study is to compare the lower extremity response and injuries of post mortem human surrogates (PMHS) tested in full-scale vehicle-pedestrian impact experiments with a small sedan and a large sport utility vehicle (SUV). The pelves and lower limbs of six PMHS were instrumented with six-degree-of-freedom instrumentation packages. The PMHS were then positioned laterally in mid-stance gait and subjected to vehicle impact at 40 km/h with either a small sedan (n=3) or a large SUV (n=3). Detailed descriptions of the pelvic and lower extremity injuries are presented in conjunction with global and local kinematics data and high speed video images. Injured PMHS knee joints reached peak lateral bending angles between 25 and 85 degrees (exceeding published injury criteria) at bending rates between 1.1 deg/ms and 3.7 deg/ms.

The injury outcome of a front-front two-vehicle crash will be a function of crash-specific, vehicle-specific, and occupant-specific parameters. This paper focuses on a preliminary methodology that was used to evaluate the potential for benefits in making vehicle-specific changes to improve the compatibility of light vehicles across the fleet. In particular, the effect on injury rates of matching vehicle frontal stiffness was estimated. The front-front crash data for belted drivers in the lighter vehicles in the crash from ten years of NASS-CDS data were examined. The frontal stiffness of each vehicle was calculated using data taken during full frontal rigid barrier tests for the U.S. New Car Assessment Program (NCAP), and only crashes coded in the CDS as “no override” were considered.

Head injuries are the most common injuries sustained by children in motor vehicle crashes regardless of age, restraint and crash direction. Previous research identified the front seat back as relevant contact point associated with head injuries sustained by restrained rear seated child occupants. The objective of this study was to conduct a test series of headform impacts to seat backs to evaluate the energy management characteristics of relevant contact points for pediatric head injury. A total of eight seats were tested: two each of 2007 Ford Focus, Toyota Corolla, 2006 Volvo S40, and 2008 Volkswagen Golf. Five to six contact points were chosen for each unique seat model guided by contact locations determined from real world crashes. Each vehicle seat was rigidly mounted in the center track position with the seatback angle adjusted to 70 degrees above the horizontal.

A kinematic analysis of the head-neck unit has been conducted in 37 simulated traffic accidents in order to investigate correlations between neck response and injuries. Belted fresh human cadavers in the age range 18 to 74 years have been used as front and rear-seat passengers. The analysed data included 23 frontal collisions, impact velocity 30 km/h, 50 km/h and 60 km/h, barrier impact and 14 90°-car to car lateral collisions with near-side passengers (6 cases) as well as far-side rear-seat passengers with an in-board upper anchoring point for the shoulder belt (8 cases). The head bending angle depended on the type of the collision. At the frontal collision, the mean head bending maxima amounted 79°, the evaluated mean angular velocity maxima and angular acceleration maxima corresponded to 41 rad/s and 2208 rad/s2, the mean maximum velocity in trajectory of the head was 10 m/s, the mean maximum acceleration along the path amounted 23 g.

This analysis is part of a retrospective real accident study of 670 occupants in 428 cars. In most cases the real accidents were reconstructed from police reports by means of photographs, accident drawings and descriptions of the damaged cars. In fatal crashes the cars, and in most cases the sites of the accidents were examined. Among 272 occupants involved in car side collisions, we found 41 belt protected near side front passengers, whose cars were impacted by another car with main impact points at the front passengers' doors and B-pillars. The analysis of the correlation between technical parameters of the real accidents and injuries of the passengers showed a high significant discrimination between MAIS and some regional AIS 0-3 on one hand, and MAIS and some regional AIS 4-6 on the other hand already for each of the technical variables EES, delta v and maximum deformation.

Recently there has been a greater awareness of the increased risk of certain injuries associated with air bag deployment, especially the risks to small occupants, often women. These injuries include serious eye and upper extremity injuries and even fatalities. This study investigates the interaction of a deploying air bag with cadaveric upper extremities in a typical driving posture; testing concentrates on female occupants. The goals of this investigation are to determine the risk of upper extremity injury caused by primary contact with a deploying air bag and to elucidate the mechanisms of these upper extremity injuries. Five air bags were used that are representative of a wide range of air bag ‘aggressivities’ in the current automobile fleet. This air bag ‘aggressivity’ was quantified using the response of a dummy forearm under air bag deployment.

The number of passenger cars equipped with side air bags is steadily increasing. With the aim of investigating the mechanical responses and the injuries of the arm under the influence of a side air bag, tests in probably higher injury risk configurations with dummies and cadavers were performed. The air bag was installed at the outer side of the seat back, with the subject seated in the driver or front passenger seat of a passenger car. During the inflation of the air bag, the left or right forearm of the subject was positioned on the arm rest while the upper arm made contact with the seat back edge. The volume of the thorax air bag was 15 litres and for the thorax-head air bag 28 litres. The dummy was instrumented at the thorax c.g. shoulder, elbow and wrist with triaxial accelerometers. In the cadaver, triaxial accelerations in three orthogonal directions were measured at the upper and the lower humerus, the upper radius and the lower radius and the first thoracic vertebrae.

This paper discusses the consumer and news media perceptions about air bags that had to be taken into account by the National Highway Traffic Safety Administration in making rulemaking decisions in 1997. Addressing these perceptions was a major concern as the agency made preparations to allow identifiable groups of people at risk from an air bag deployments to have on-off switches installed in their vehicles.

The protection of a vehicle occupant in a frontal crash is a combination of vehicle front structural design and occupant restraint design. Once chosen and manufactured, these design features must interact with a wide variety of structural characteristics in potential crash partners. If robust, the restraint design will provide a high level of protection for a wide variety of crash conditions. This paper examines how robust a given restraint system is for occupant self-protection and how frontal design can improve the restraint performance of potential crash partners, thus improving their restraint robustness as well. To examine restraint robustness in self protection, the effect of various vehicle deceleration characteristics on occupant injury potential is investigated for a given restraint design. A MADYMO model of a 1996 Taurus interior and its restraint system with a Hybrid III 50th percentile male dummy are simulated and subjected to 650 crash pulses taken during 25 years of U.S.

Based on a long recognized need, the National Highway Traffic Safety Administration (NHTSA) has begun to reexamine the potential for international harmonization of side impact requirements. To this end, NHTSA, as directed by the U.S. Congress, has recently submitted a report to the Congress on the agency plans for achieving harmonization of the U.S. and European side impact regulations. The first phase of this plan involves crash testing vehicles compliant to FMVSS 214 to the European Union side impact directive 96/27/EC. This paper presents the results to date of this research. The level of safety performance of the vehicles based on the injury measures of the European and U.S. side impact regulations is assessed.

Diffuse brain injuries are very common in side impacts, accounting for more than half of the injuries to the head. These injuries are often sustained in less severe side impacts. An English investigation has shown that diffuse brain injuries often originate from interior contacts, most frequently with the side window. They are believed to be mainly caused by quick head rotational motions. This paper describes a test method using a Hybrid III dummy head in a wire pendulum. The head impacts a simulated side window or an inflatable device, called the Inflatable Curtain (IC), in front of the window, at different speeds, and at different impact angles. The inflated IC has a thickness of around 70 mm and an internal (over) pressure of 1.5 bar. The head was instrumented with a three axis accelerometer as well as an angular velocity sensor measuring about the vertical (z) axis. The angular acceleration was calculated.

In crashes between heavy trucks and light vehicles, most of the fatalities are the occupants of the light vehicle. A reduction in heavy truck stopping distance should lead to a reduction in the number of crashes, the severity of crashes, and consequently the numbers of fatalities and injuries. This study made use of the National Advanced Driving Simulator (NADS). NADS is a full immersion driving simulator used to study driver behavior as well as driver-vehicle reactions and responses. The vehicle dynamics model of the existing heavy truck on NADS had been modified with the creation of two additional brake models. The first was a modified S-cam (larger drums and shoes) and the second was an air-actuated disc brake system. A sample of 108 CDL-licensed drivers was split evenly among the simulations using each of the three braking systems. The drivers were presented with four different emergency stopping situations.

Since 1994, the New Car Assessment Program (NCAP) of the National Highway Traffic Safety Administration (NHTSA) has compiled upper neck loads for the belt and air bag restrained 50th percentile male Hybrid III dummy. Over five years from 1994 to 1998, in frontal crash tests, NCAP collected upper neck data for 118 passenger cars and seventy-eight light trucks and vans. This paper examines these data and attempts to assess the potential for neck injury based on injury criteria included in FMVSS No. 208 (for the optional sled test). The paper examines the extent of serious neck injury in real world crashes as reported in the National Automotive Sampling System (NASS). The results suggest that serious neck injuries do occur at higher speeds for crashes involving occupants restrained by belts in passenger cars.

On-board Camera/Video Imaging Systems (C/VISs) for heavy vehicles display live images to the driver of selected areas to the sides, and in back of the truck's exterior using displays inside the truck cabin. They provide a countermeasure to blind-spot related crashes by allowing drivers to see objects not ordinarily visible by a typical mirror configuration, and to better judge the clearance between the trailer and an adjacent vehicle when changing lanes. The Virginia Tech Transportation Institute is currently investigating commercial motor vehicle (CMV) driver performance with C/VISs through a technology field demonstration sponsored by the National Highway Traffic Safety Administration (NHTSA) and the Federal Motor Carrier Safety Administration (FMCSA). Data collection, which consists of recording twelve CMV drivers performing their daily employment duties with and without a C/VIS for four months, is currently underway.

This paper presents the details of the model for the physical steering system used on the National Advanced Driving Simulator. The system is basically a hardware-in-the-loop (steering feedback motor and controls) steering system coupled with the core vehicle dynamics of the simulator. The system's torque control uses cascaded position and velocity feedback and is controlled to provide steering feedback with variable stiffness and dynamic properties. The reference model, which calculates the desired value of the torque, is made of power steering torque, damping function torque, torque from tires, locking limit torque, and driver input torque. The model also provides a unique steering dead-band function that is important for on-center feel. A Simulink model of the hardware/software is presented and analysis of the simulator steering system is provided.

Mathematical models in combination with mechanical tests were used to develop a frontal crash sensing system and algorithm. The required sensor closure time for the initiation of driver side airbag deployment was estimated by means of multi body dynamics occupant models. The crash sensing system and algorithm were developed using predictions from a finite element model of the front structure of a passenger vehicle. All models were validated by means of mechanical tests. Generally good agreement was obtained between the predictions from the models and the results from the mechanical tests. In the sensor closure time analysis two occupant sizes were used, the 50%-ile male and the 5%-ile female occupant. Two restraint conditions were evaluated, no belt and a belt system incorporating a pretensioner. A number of crash pulses of various severity were used.

The National Highway Traffic Safety Administration and the University of Michigan Transportation Institute are investigating truck design countermeasures to provide safety benefits during collisions with light vehicles. The goal is to identify approaches that would best balance costs and benefits. This paper outlines the first phase of this study, an analysis of two-vehicle, truck/light vehicle crashes from 1996 through 1998 using several crash data bases to obtain a current description and determine the scope of the aggressivity problem. Truck fronts account for 60% of light vehicle fatalities in collisions with trucks. Collision with the front of a truck carries the highest probability of fatal (K) or incapacitating (A) injury. Truck sides account for about the same number of K and A-injuries combined as truck fronts, though injury probability is substantially lower than in crashes involving the front of a truck.

The National Highway Safety Administration (NHTSA) is collecting crash data relating to large trucks. Two data collection programs are specified. One is a crash causation study to investigate the cause of fatal and serious large truck crashes over two years. The other study is a continuous effort collecting data on large truck motor carrier crashes in each state, as coded on police accident reports.

This paper describes ongoing research conducted by the National Highway Traffic Safety Administration (NHTSA) to evaluate the potential of safety restraints on large school buses. School bus transportation is one of the safest forms of transportation in the United States. Large school buses provide protection because of their visibility, size, and weight, as compared to other types of motor vehicles. Additionally, they are required to meet minimum Federal Motor Vehicle Safety Standards (FMVSS) mandating compartmentalized seating, emergency exits, roof crush and fuel system integrity, and minimum bus body joint strength.

This paper provides an overview of a cooperative research program between General Motors Corporation and the National Highway Traffic Safety Administration to conduct a field operational test of a rear-end collision warning system. A description of the system architecture is also presented.