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This project assessed current or proposed protocols for improving the usability of LATCH (Lower Anchors and Tethers for Children). LATCH hardware in the left second-row position of 98 2011 or 2010 model-year vehicles was evaluated using ISO and SAE LATCH usability rating guidelines. Child restraint/vehicle interaction was assessed using ISO and NHTSA proposed procedures. ISO ratings of vehicle LATCH usability ranged from 41% to 78%, while vehicles assessed using the SAE draft recommended practice met between 2 and all 10 of the recommendations that apply to all vehicles. There was a weak relationship between vehicle ISO usability ratings and the number of SAE recommended practices met by a vehicle. Twenty vehicles with a range of vehicle features were assessed using the ISO vehicle-child restraint form and 7 child restraints; ISO vehicle-child restraint interaction scores ranged from 14% to 86%.

Using 1988-95 data from the Fatality Analysis Reporting System, risk of death was compared among front- and rear-seated passengers ages 12 and younger involved in fatal crashes, controlling for restraint use, passenger airbags, and other variables. Among children sitting in the rear, risk of death was reduced about 35 percent in vehicles without passenger airbags and about 50 percent in vehicles with passenger airbags (difference was not statistically significant). Rear seats were protective for both restrained and unrestrained children. Children were about 10-20 percent less likely to die in rear center than in rear outboard positions.

Anthropometric test devices (ATDs) instrumented with potentiometers and accelerometers are used regularly to assess thoracic injury risk in side impact crash tests. Measurements from these sensors are compared with injury assessment reference values (IARVs) for lateral loading to establish the risk of injury for humans subjected to similar impacts. In crash tests, the deflections and deflection rates derived from these two types of sensors (potentiometers vs. accelerometers) have varying degrees of agreement. In some cases, differences can be relatively large. In the past, it was unclear whether the reason for the differences was off-axis loading that misaligned the accelerometers used in the calculation, an inherent inability of the potentiometer to capture high deflection rates under certain conditions, or some other phenomenon.

The Insurance Institute for Highway Safety installed a variety of infant, toddler, and booster restraints in vehicles subjected to high-speed frontal offset crash tests to assess the effects of severe crashes on the structural integrity of the restraints and their associated hardware (harnesses, buckles, clips, etc.). The child restraints were inspected before and after each test, and all damage was recorded. In some of the tests, forces and accelerations were recorded on the appropriate size child dummy properly secured in the child restraint. After a single severe crash, most restraints had sustained some damage, albeit minimal. Repeated tests indicated that these child restraints could withstand the forces of an additional crash with only minor additional damage. Dummy injury results suggest that current injury risk curves overstate the risk of neck injury to most properly restrained children.

The knee and ankle joint pivots of the Hybrid III dummy's leg are positioned in approximately the same orientation as the knee and ankle joint rotation centers of a human in a normal driving posture. However, the dummy's leg assembly is not simply a straight member between these two pivots. It is a zigzag-shaped solid link composed of one long straight section in the middle and short angled sections at either end, which form the pivots. The upper and lower tibia load cells are mounted on the straight middle section, making the upper tibia load cell location anterior to the line between the ankle and knee pivots and the lower tibia load cell location slightly posterior to the line between the pivots. Hence, an approximately vertical force on the foot can act along the line behind the upper tibia load cell and in front of the lower tibia load cell, creating bending moments.

This study, which is an extension of an earlier study, examined an additional 64 frontal crashes of airbag-equipped vehicles in the 1997-98 National Automotive Sampling System Crashworthiness Data System (NASS/CDS) in which the driver died. The principal cause of death in each case was determined based on an examination of the publicly available case materials, which primarily consisted of the crash narrative, the injury/source summary, and photographs of the crashed vehicle. Results were consistent with the earlier analyses of the 1990-96 NASS/CDS files. In the combined data set (1990-98), gross deformation of the occupant compartment was the leading cause (42 percent) of driver deaths in these 116 frontal crashes. The force of the deploying airbag (16 percent) and ejection from the vehicle (13 percent) also accounted for significant portions of the driver deaths in these frontal crashes. There continues to be little or no evidence that airbags deploy with too little energy.

The current study estimates about 5 percent of the U.S. female population sits closer than 10 inches from the steering wheel; 35 percent for the smallest 10 percent of the female population. Of the females sitting closer than 10 inches, 66 percent sit within 9-10 inches, and 17 percent sit within 8-9 inches. In a separate study, drivers sitting within 9-10 inches were able to increase this distance to 10 inches or more and still drive comfortably in a number of cars by making a few minor seating adjustments.

The purpose of this study was to assess, by use of computer simulations, the effectiveness of motorcycle helmets in reducing head and neck injuries in motorcyclist impacts. The computer model used was the MVMA Two-Dimensional Crash Victim Simulator. The study investigated a wide variety of impact conditions in order to establish a broad overall view of the effectiveness of helmets. It was found that helmet use invariably reduces dynamic responses which have a role in producing head injury and, in addition, almost always reduces the severity of neck response as well. For no configuration or condition does the helmet greatly increase the likelihood of neck injury. Thus, these simulations of a wide spectrum of motorcyclist impacts provide further evidence that helmet use significantly reduces the likelihood and severity of both head and neck injuries. This study was supported by the Insurance Institute for Highway Safety.

Laws requiring seat belt use have had some limited success in reducing occupant fatalities. However, fatality reductions have been considerably less than expected from the reported increases in belt use rates because belt use by those in crashes has not increased to the same extent. Occupants most likely to be in serious crashes are least likely to increase their use of belts in response to laws. In addition, many involuntary belt users comply with belt use laws by wearing their belts incorrectly, in ways that greatly reduce their effectiveness, and many in front seats who wear belts in response to laws are susceptible to being impacted in crashes by unbelted rear seat occupants. The incomplete success of belt use laws does not reduce their importance as a countermeasure, but does reinforce the importance of providing automatic (“passive”) protection to vehicle occupants as an alternative or supplementary countermeasure.

The Maryland State Police, in cooperation with Saint-Gobain Vitrage and the Insurance Institute for Highway Safety, installed anti-lacerative Securiflex Inner Guard windshields in a number of their new vehicles. The exposure and visibility characteristics of these windshields have been monitored and compared to the experience of standard HPR windshields of similar vehicles in the fleet. The performance of the Securiflex windshields has shown visibility properties similar to standard windshields. More importantly, the superior safety characteristics of the Securiflex windshield prevented a Maryland State trooper from recieving lacerative injuries as the result of a collision in which his vehicle struck the rear of another vehicle.

This paper examines the effects that downsizing has had on occupant injury. Statistical models are derived which demonstrate the relative risks associated with downsized cars and restraint use. Then actual occupant injuries are analysed to show how the total pattern of occupant injuries changes with downsizing. Each additional thousand pounds of vehicle mass decreases the odds of a driver injury in a crash by 34 percent when the driver is not restrained. For restrained drivers, this decrease is 25 percent per thousand. Restraint use further decreases the odds of a driver injury by two-thirds. To gain the same reduction in injury odds afforded the belted driver of a 2500 pound passenger car, the unbelted driver requires a 4325 pound car. For unrestrained occupants, the instrument panel, steering assembly and windshield (in frontal impacts) are the most frequent sources of injury.

Data on deaths of car occupants during the calendar year 1975 were obtained from the National Highway Traffic Safety Administration's Fatal Accident Reporting System, and national vehicle registration counts were obtained from R. L. Polk National Profile as of July 1, 1975. Occupant deaths per 10,000 registered cars in the 1971 through 1974 model years were examined by vehicle size. Occupant death rates generally increase as car size decreases. The relationship between smaller cars and increased deaths is especially pronounced in frontal crashes, and in car into other vehicle crashes. Because of this, increased occupant crash protection in frontal crashes-such as provided by air bags and passive seat belts-could substantially reduce much of the disadvantage presently faced by occupants of small cars.

Seat belt use laws in New York, Michigan, New Jersey, and Illinois reduced front seat occupant fatalities by an estimated 16, 10, 6 and five percent respectively, during the months in 1985 they were in effect. Only the reduction for New York was statistically significant, but the similarity between the pattern of fatality reductions and the pattern of increases in seat belt use lends credibility to the estimates. Each reduction was less than expected given the known effectiveness of seat belts and the observed rates of use in noncrash populations, suggesting again that seat belt use laws are less successful in increasing belt use among those who are more likely to be in crashes. Pedestrian fatalities were unaffected by the laws, indicating that “risk compensation” was not a factor modifying the success of the laws.

Using data from the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) for1995-96, this study updates previous analyses of driver fatalities in airbag-equipped vehicles in the NASS/CDS database for 1989-93 and 1989-94. A total of 59 cases of frontal crashes of airbag-equipped vehicles with driver fatalities were identified in these 8 years of NASS/CDS data, but in 9 cases the fatalities were not related to the impacts (e.g., fire, medical condition). Vehicle intrusion was the cause of the fatal injuries in 27 cases, and 7drivers died from injuries sustained when they were either partially or totally ejected from their vehicles. There was one case in which the airbag did not deploy, although the crash conditions indicated it should have. One driver died from contact with a nonintruding vehicle surface, and the causes of the fatal injuries in 5 cases were unknown.

Automobile safety has improved since the 1960s, mostly because of improved vehicle structures and restraint systems. Another round of revolutionary change is promised by advanced information technologies, but it's unlikely that all of these will improve safety. In particular, many of these technologies change the driving task, and it's critical to understand how drivers respond to the changes because the responses may enhance or counteract any potential safety benefits. This paper will discuss what is necessary to predict driver response.

Pedestrian protection evaluations have been developed to encourage vehicle front-end designs that mitigate the consequences of vehicle-to-pedestrian crashes. The European New Car Assessment Program (Euro NCAP) evaluates pedestrian head protection with impacts against vehicle hood, windshield, and A-pillars. The Global Technical Regulation No. 9 (GTR 9), being evaluated for U.S. regulation, limits head protection evaluations to impacts against vehicle hoods. The objective of this study was to compare results from pedestrian head impact testing to the real-world rates of fatal and incapacitating injuries in U.S. pedestrian crashes. Data from police reported pedestrian crashes in 14 states were used to calculate real-world fatal and incapacitating injury rates for seven 2002-07 small cars. Rates were 2.17-4.04 per 100 pedestrians struck for fatal injuries and 10.45-15.35 for incapacitating injuries.

In 2012, the Insurance Institute for Highway Safety (IIHS) began a 64 km/h small overlap frontal crash test consumer information test program. Thirteen automakers already have redesigned models to improve test performance. One or more distinct strategies are evident in these redesigns: reinforcement of the occupant compartment, use of energy-absorbing fender structures, and the addition of engagement structures to induce vehicle lateral translation. Each strategy influences vehicle kinematics, posing additional challenges for the restraint systems. The objective of this two-part study was to examine how vehicles were modified to improve small overlap test performance and then to examine how these modifications affect dummy response and restraint system performance. Among eight models tested before and after design changes, occupant compartment intrusion reductions ranged from 6 cm to 45 cm, with the highest reductions observed in models with the largest number of modifications.

A BioRID (biofidelic rear impact dummy) representing a 50th percentile adult male was seated in the front passenger seat of six new vehicle models in a series of low-speed crash tests. The neck injury criterion (NIC) and other dummy responses that may indicate whiplash injury risk were recorded. Both front-into- rear and rear-into-barrier tests with an average velocity change of 11 km/h were conducted. Head restraints were tested in both adjusted (up) and unadjusted (down) positions. Damage to all models was minor, and longitudinal vehicle accelerations were low (less than 7 g). Neck extension angles and bending moments were much less than injury assessment reference values (IARV) (80 degrees and 57 Nm, respectively), indicating low risk of hyperextension injuries. Neck tension and transverse forces also were less than IARVs used to indicate the risk of more serious neck injuries.

The Insurance Institute for Highway Safety (IIHS) is investigating small overlap crash test procedures for a possible consumer information program. Analysis of real-world small overlap crashes found a strong relationship between serious head and chest injuries and occupant compartment intrusion. The main sources of serious head injuries were from the A-pillar, dash panel, or door structure, suggesting head trajectories forward and outboard possibly bypassing the airbag. Chest injuries mainly were from steering wheel intrusion and seat belt loading. In developing this program, two test dummies were evaluated for predicting occupant injury risk: midsize male Hybrid III and THOR. In the collinear small overlap crash tests conducted here, results from the two dummies were similar. Both predicted a low risk of injury to the head and chest and sometimes a high risk of injury to the lower extremities. Head and torso kinematics also were similar between dummies.

Current requirements for rear underride guards on large trucks are set by the National Highway Traffic Safety Administration in Federal Motor Vehicle Safety Standards (FMVSS) 223 and 224. The standards have been in place since 1998, but their adequacy has not been evaluated apart from two series of controlled crash tests. The current study used detailed reviews of real-world crashes from the Large Truck Crash Causation Study to assess the ability of guards that comply with certain aspects of the regulation to mitigate passenger vehicle underride. It also evaluated the dangers posed by underride of large trucks that are exempt from guard requirements. For the 115 cases meeting the inclusion criteria, coded data, case narratives, photographs, and measurements were used to examine the interaction between study vehicles. The presence and type of underride guard was determined, and its performance in mitigating underride was categorized.