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The research question investigated in this study is what are the key attributes of foot and ankle injury in the between-rail frontal crash? For the foot and ankle, what was the type of interior surface contacted and the type of resulting trauma? The method was to study with in-depth case reviews of NASS-CDS cases where a driver suffered an AIS=2 foot or ankle injury in between-rail crashes. Cases were limited to belted occupants in vehicles equipped with air bags. The reviews concentrated on coded and non-coded data, identifying especially those factors contributing to the injuries of the driver's foot/ankle. This study examines real-world crash data between the years 1997-2009 with a focus on frontal crashes involving 1997 and later model year vehicles. The raw data count for between-rail crashes was 732, corresponding to 227,305 weighted, tow-away crashes.

An evaluation of the four injury risk curves proposed in the NHTSA NCAP for estimating the risk of AIS≻=3 injuries to the head, neck, chest and AIS≻=2 injury to the Knee-Thigh-Hip (KTH) complex has been conducted. The predicted injury risk to the four body regions based on driver dummy responses in over 300 frontal NCAP tests were compared against those to drivers involved in real-world crashes of similar severity as represented in the NASS. The results of the study show that the predicted injury risks to the head and chest were slightly below those in NASS, and the predicted risk for the knee-thigh-hip complex was substantially below that observed in the NASS. The predicted risk for the neck by the Nij curve was greater than the observed risk in NASS by an order of magnitude due to the Nij risk curve predicting a non-zero risk when Nij = 0. An alternative and published Nte risk curve produced a risk estimate consistent with the NASS estimate of neck injury.

This study tracks vehicle design changes and frontal crash test performance in NHTSA's NCAP and IIHS consumer information tests since the mid-90s for the Honda Accord and Toyota Camry. The objective was to provide insights into how passenger cars have changed in response to frontal consumer information tests. The history of major design changes for each model was researched and documented. The occupant injury measures from both NHTSA and IIHS were computed and the ratings compiled for several generations of both vehicles. Changes in vehicle crash pulse and occupant injury measures from both NCAP and IIHS tests, and from Canadian low speed rigid barrier tests, when available, were used to assess driver frontal protection for various vehicle generations. Loading of the rigid barrier in NCAP tests was used to evaluate front end stiffness changes over the years.

The objective of the present study is to develop a better understanding of the reasons for airbag non-deployment in frontal crashes that produce serious injuries. The FARS data shows an increasing trend of fatal crashes involving airbag non-deployment with a higher fatality risk in recent model year vehicles. The reported number of fatalities in such crashes has increased by about 50 percent (from 500 per year to 780 per year) in the last five years. The percentage of fatalities with non-deployments has doubled in vehicles model year 1998 and later compared to earlier model years. Multiple impacts contribute to about 90 percent of the FARS frontal crashes with non-deployments. Crashes with a curb hit or guardrail impact as the first harmful event and a narrow impact crash with a tree or pole as a subsequent harmful event is the most frequent crash scenario in non-deployment related fatal crashes.

In this study, the level of protection offered to rear seat occupants in frontal crashes is investigated. The Fatality Analysis Reporting System (FARS) and National Automotive Sampling System Crashworthiness Data System (NASS CDS) databases were used for the analyses. The investigation focused on: 1- estimating the fatality protection effectiveness of the rear seat position relative to the right front seat position, using the double paired comparison method, 2- evaluating the effect of control group selection method on effectiveness predictions, and 3- identifying trends in rear seat occupant protection over model years of vehicles. By applying a uniform control group to the double paired comparison analysis of FARS data, this study suggests that all ages of occupants are safer in the rear seat than in the right front seat. Effectiveness estimates ranged from 5.9% to 82% for different age groups of occupants.

The National Automotive Sampling System’s Crashworthiness Data System (NASS CDS) was used to study rear occupant injuries in frontal crashes. The risks of injury for the rear passengers of different age groups were calculated and compared to the risks of injury for the front occupants. Furthermore, the risks of injury were investigated for the rear and front adult occupants over model years of vehicles. Distribution of injuries among body regions and vehicle contact points were also investigated for the rear adult occupants. While the rear occupants were more protected than the front occupants in most of the groups studied, an increasing trend was observed in the risk of injury of the rear adult occupants over the model years of the vehicles.

The purpose of this paper is to assess the vehicle environment that a child occupant, between the ages of seven and thirteen years old, is exposed to in a real world crash. The focus of analysis is on those child occupants that are seated at the struck side in a lateral collision. This study was based on data extracted from the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) between years 1991-2006. Analysis was based upon the evaluation of the projected consequence of injury to the child occupants. The societal costs generated as a result of occupant injuries were quantified. The societal cost, or Harm, acts as a measure of consequence of occupant exposure to the vehicle environment, when involved in a collision. The Harm was determined as a function of ΔV, principal direction of force, vehicle extent of damage, the pattern of damage to the vehicle, and the magnitude of intrusion based on the occupant seating position.

Vehicle stiffness is one of the three major factors in vehicle to vehicle compatibility in a frontal crash; the other two factors are vehicle mass and frontal geometry. Vehicle to vehicle compatibility in turn is an increasingly important topic due to the rapid change in the size and characteristics of the automotive fleet, particularly the increase of the percentage of trucks and SUVs. Due to the non-linear nature of the mechanics of vehicle structure, frontal stiffness is not a properly defined metric. This research is aimed at developing a well defined method to quantify frontal stiffness for vehicle-to-vehicle crash compatibility. The method to be developed should predict crash outcome and controlling the defined metric should improve the crash outcome. The criterion that is used to judge the aggressivity of a vehicle in this method is the amount of deformation caused to the vulnerable vehicles when crashed with the subject vehicle.

This paper creates a worksheet to thoroughly document vehicle damage during an incompatible vehicle-to-vehicle frontal crash. This data form serves as a supplement to the current and already established NASS inspection forms. It will assist biomechanics research by determining the extent by which incompatibility caused or changed occupants' injuries through structural analysis of the vehicles. This study identifies deficiencies in the current NASS inspection system for compatibility, and develops new measurable parameters to document the crash and associate injury to it.

Automatic Crash Notification (ACN) technology provides an opportunity to rapidly transmit crash characteristics to emergency care providers in order to improve timeliness and quality of care provided to occupants in the post crash phase. This study evaluated the relative value of crash attributes in providing useful information to assist in the identification of crashes where occupants may be seriously injured. This identification includes an indication of whether a crash is likely to require a level of emergency response with higher priority than is needed for most crashes reported by ACN Systems. The ability to predict serious injury using groupings of variables has been determined. In this way, the consequence of not transmitting each variable can be estimated. In addition, the incremental benefit of voice communication is shown.

One of the leading causes of death in automotive crashes is traumatic rupture of the aorta (TRA) or blunt aortic injury (BAI). The risk of fatality is high if an aortic injury is not detected and treated promptly. The objective of this study is to investigate TRA mechanisms using finite element (FE) simulations of reconstructed real-world accidents involving aortic injury. For this application, a case was obtained from the William Lehman Injury Research Center (WLIRC), which is a Crash Injury Research and Engineering Network (CIREN) center. In this selected crash, the case vehicle was struck on the left side with a Principal Direction of Force (PDoF) of 290 degrees. The side structure of the case vehicle crushed a maximum of 0.33 m. The total delta-V was estimated to be 6.2 m/s. The occupant, a 62-year old mid-sized male, was fatally injured. The occupant sustained multiple rib fractures, laceration of the right ventricle, and TRA, among other injuries.

In December 2003, fifteen participating Automobile Manufacturers announced the adoption of voluntary standards for geometric compatibility in frontal crashes. In an October 2003 report, Insurance Institute of Highway Safety (IIHS) estimated that an 8 to 28 percent fatality reduction might be achieved with better geometric and stiffness compatibility (O’Neill, 2003). This benefit was based on comparing the fatality risks of car occupants in car-to-car collisions and in car-to-SUV collisions. Reduced occupant compartment intrusion was cited as the principal advantage gained by compatibility improvements. However, the study did not actually examine the role that intrusion played in causing the fatalities. This study examines the magnitude of serious injuries in frontal crashes that could be addressed by reducing occupant compartment intrusion. Each frontal vehicle-to-vehicle case in William Lehman Injury Research Center (WLIRC) data was examined to determine the cause of each injury.

In the effort to understand and solve the frontal crash compatibility problem, one needs to use values of frontal stiffness. Various definitions of stiffness have been used in other studies based on measurements from NHTSA's 35mph frontal NCAP test. Those definitions varied from assuming a linear stiffness based on static crush to more refined ones that vary with time dependent crush. A major consideration in selecting a method is the amount of vehicle damage that occurs in an incompatible crash. To partially address this issue, a method was introduced based on the energy absorbed in a front to front crash at 25mph approach speed. Four alternative definitions of stiffness were studied.

Seventeen full-scale crash tests were conducted to evaluate technologies to reduce the vulnerability of sidesaddle tanks on full size GM pickup trucks manufactured during the period 1973-1987. These vehicles were alleged by the U.S. Department of Transportation to be vulnerable in severe side impacts. The test program was intended to evaluate designs that would reduce vulnerability in all crash directions. The best test results were obtained by two strategies that relocated the tank to less vulnerable locations. The two locations were: (1) in the cargo bed (bed mounted tank) and (2) underneath the bed, ahead of the rear axle and between the frame rails (center-mounted tank). Tanks mounted in these locations were subjected to a series of crash tests that simulated severe front, side, rear and rollover crashes. The crash environment for these tests was more severe than required by FMVSS 301 “Fuel System Integrity”.

In a side impact, the occupants on both the struck, or near side, of the vehicle and the occupants on the opposite, or far side, of the vehicle are at risk of injury. Since model year 1997, all passenger cars in the U.S. have been required to comply with FMVSS No. 214, a safety standard that mandates a minimum level of side crash protection for near side occupants. No such federal safety standard exists for far side occupants. The mechanism of far side injury is believed to be quite different than the injury mechanism for near side injury. Far side impact protection may require the development of different countermeasures than those which are effective for near side impact protection. This paper evaluates the risk of side crash injury for far side occupants as a basis for developing far side impact injury countermeasures. Based on the analysis of NASS/CDS 1993–2002, this study examines the injury outcome of over 4500 car, light truck, and van occupants subjected to far side impact.

The U.S. Department of Transportation-sponsored Crash Injury Research and Engineering Network (CIREN) program offers a reasonable look at the efficacy of second-generation air bags. This paper examines the data from the William Lehman Injury Research Center (WLIRC). The WLIRC data is a near census of crashes in the Miami-Dade region with occupants that appear to be severely injured. The percentage of deaths among trauma patients in the WLIRC data as a function of delta-V for first-generation air bags was higher than expected at lower delta-V's. There were nine driver fatalities at delta-V's of less than 20 mph (four involving short stature occupants, four with elderly occupants, and one due to significant intrusion and/or vehicle incompatibility). The data supported NHTSA's conclusion that first-generation air bags were too aggressive for occupants in close proximity to the deploying air bag and too aggressive for older persons.

Occupants exposed to far-side crashes are those seated on the side of the vehicle opposite the struck side. This study uses the NASS/CDS 1988–98 to determine distributions of serious injuries among restrained occupants exposed to far-side crashes and the sources of the injuries. Vehicle-to-vehicle crash tests were conducted to study dummy kinematics. The NASS/CDS indicated that the head accounted for 45% of the MAIS 4+ injuries in far-side collisions and the chest/abdomen accounted for 39%. The opposite-side interior was the most frequent contact associated with driver AIS 3+ injuries (26.9%). The safety belt was second, accounting for 20.8%. Vehicle-to-vehicle side impact tests with a 60 degree crash vector indicated that different safety belt designs resulted in different amounts of head excursion for the far side Hybrid III dummy. For all three point belt systems tested, the shoulder belt was ineffective in preventing large amounts of head excursion.

The URGENCY algorithm uses data from on-board crash recorders to assist in identifying crashes that are most likely to have time critical (compelling) injuries. The injury risks projected by using the NASS/CDS data are the basis for the URGENCY algorithm. This study applied the algorithm retrospectively to a population of injured occupants in the database from the University of Miami School of Medicine, William Lehman Injury Research Center (WLIRC). The population selected was adult occupants in frontal crashes that were protected by three-point belts plus an air bag. For the cases with greater than 50% predicted MAIS 3+ injury probability, 96% of the occupants in the study had MAIS 3+ injuries. For the cases with less than 10% predicted MAIS 3+ injury probability, 63% did not have MAIS 3+ injuries. Most of the of MAIS 3+ injuries not predicted involved injuries in multiple impact crashes, pole crashes or close-in occupants injured by air bag deployment.

Rollover crashes continue to be a serious and growing vehicle safety problem. Rollovers account for about 9% of passenger car crashes, and 26% of light truck crashes. Belt use in rollover crashes is about 51%, compared with 62% in planar crashes. Overall, 26.4% of the serious and fatal injuries to occupants exposed to crashes are in rollovers. Among this injured population 74.4% are unbelted. In light trucks, rollovers account for 47.4% of the serious or fatal injuries. Unbelted occupants suffer about 87% of the serious injuries and fatalities in light truck rollovers. The use of safety belts offers a dramatic reduction in injury rates for rollover crashes. For belted occupants of pickup trucks and utility vehicles in rollover crashes, the injury rates are about the same as for belted occupants of passenger cars in planar crashes. Improvementsts in safety belts offer large opportunities in safety.

Beginning in model year 1997, BMW introduced an innovative head protection system HPS called the Inflatable Tubular Structure (HPS). Tests indicate that the system dramatically reduces the severity of head impacts in side crashes. This investigation is an evaluation of casualty abatement benefits that are derived from applying injury measures based on the HPS test results to the population in US National Accident Sampling System (NASS/CDS). The results of component and vehicle crash tests are summarized. The procedures for estimating benefits are described along with the benefits in terms of injuries mitigated, maximum injuries to occupants mitigated, and fatalities prevented.