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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%.

The Insurance Institute for Highway Safety (IIHS) evaluates autonomous emergency braking (AEB) systems as part of its front crash prevention (FCP) ratings. To prepare the test vehicles' brakes, each vehicle must have 200 miles on the odometer and be subjected to the abbreviated brake burnish procedure of Federal Motor Vehicle Safety Standard (FMVSS) 126. Other organizations conducting AEB testing follow the more extensive burnishing procedure described in FMVSS 135; Light Vehicle Brake Systems. This study compares the effects on AEB performance of the two burnishing procedures using seven 2014 model year vehicles. Six of the vehicles achieved maximum AEB speed reductions after 60 or fewer FMVSS 135 stops. After braking performance stabilized, the Mercedes ML350, BMW 328i, and Volvo S80 showed increased speed reductions compared with stops using brand new brake components.

The SAE J826 H-point machine was designed to measure occupant accommodation dimensions relative to a loaded seat. It has become an intrinsic part of various crash dummy set up processes, but it has never had a formal calibration procedure. Whilst H-point location appears to be consistent from one device to another, the weight hanger locations show greater variability, and this can consequently affect the height and backset measurements of head restraints taken with a head restraint measuring device mounted upon the weight hangers. This paper describes the development of a calibration procedure and jig to measure the location of the weight hangers so that adjustments can be made if necessary. This procedure and calibration tool will enable more consistent seat evaluations, dummy set up, and consistently effective anti-whiplash seat designs.

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.

A review of 39 driver fatalities in 1990-93 cars with air bags from the National Accident Sampling System indicated most of these fatalities were due to causes unrelated to frontal air bag performance. Two-thirds occurred in side-impact or rollover crashes, in which air bag effectiveness is limited; of 15 frontal crash fatalities, 6 died of causes unrelated to the frontal impact and 5 in cars with severe intrusion. The remaining four fatalities, three of whom were unbelted, were in moderate to high severity crashes which could have been survivable; however the deploying air bags, instead of protecting, probably contributed to the fatal injuries. A similar review of 12 fatalities of unbelted drivers in cars without air bags revealed 3 could have been prevented by air bags, but 4 were in crashes that could have put them in position to be injured by the air bag.

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.

The concepts of “cost-benefit” and “cost-effectiveness” are increasingly cropping up in debate over present and future motor vehicle standards. Often they are introduced to attack, or justify, a particular standard. Just as often, they are misunderstood and misused. Since a motor vehicle safety performance standard has no costs per se, it cannot be evaluated either in cost-benefit or cost-effectiveness terms. It is the particular design alternatives available to manufacturers to achieve the objectives of a standard that have societal costs. The various design alternatives can be evaluated. Cost-effective designs should be chosen to minimize societal costs, and until there is evidence that cost-effective designs have been chosen, cost-benefit studies are premature.

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.

After decades of focus on car designs that improve the crash protection of occupants in their own cars, some theorists have refocused their attention on vehicle aggressivity, or more generally, the compatibility of vehicles when they crash with each other. Real-world fatal crash data reveal important issues of compatibility related to the broad mix of types and sizes of vehicles in the fleet. However, these data also show that incompatibility among passenger vehicles has accounted for only a small proportion of crash fatalities on U.S. roads and that modifications of the more aggressive vehicles, though appropriate and necessary, will have relatively small effects. Interventions to curtail the development and sale of the largest and heaviest passenger vehicles would be ineffective.