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Far-side occupants are not addressed in current government regulations around the world even though they account for up to 40% of occupant HARM in side impact crashes. Consequently, there are very few crash tests with far-side dummies available to researchers. Sled tests are frequently used to replicate the dynamic conditions of a full-scale crash test in a controlled setting. However, in far-side crashes the complexity of the occupant kinematics is increased by the longer duration of the motion and by the increased rotation of the vehicle. The successful duplication of occupant motion in these crashes confirms that a sled test is an effective, cost-efficient means of testing and developing far-side occupant restraints or injury countermeasures.

The energy dissipated by the fracture of wooden utility poles during vehicle impacts is not currently well documented, is dependent upon non-homogenous timber characteristics, and can therefore be difficult to quantify. While there is significant literature regarding the static and quasi-static properties of wood as a building material, there is a narrow body of literature regarding the viscoelastic properties of timber used for utility poles. Although some theoretical and small-scale testing research has been published, full-scale testing has not been conducted for the purpose of studying the vehicle-pole interaction during impacts. The parameters that define the severity of the impact include the acceleration profile, vehicle velocity change, and energy dissipation. Seven full-scale crash tests were conducted at Exponent's Arizona test facility utilizing both moving deformable and non-deformable barriers into new wooden utility poles.

Low-speed collisions between tractor-semitrailers and passenger vehicles may result in large areas of visible damage to the passenger vehicle, but often produce limited damage to the tractor-semitrailer. Despite this, such accidents may lead to assertions of serious injury to the tractor driver and/or sleeper compartment occupant. Research regarding the impact environment and resulting injury potential of the occupants during these types of impacts is limited. This research investigated driver and sleeper compartment occupant responses to relatively low-speed and low-acceleration impact events. Five crash tests involving impact between a tractor-semitrailer and a passenger car were conducted. The test vehicles were a van semitrailer pulled by a tractor and three identical mid-sized sedans. The occupants of the tractor included a human driver and an un-instrumented Hybrid III 50th-percentile-male anthropomorphic test device (ATD).

The average body weight of the US population has increased over time. This study investigates the effect of increasing weight on seat and occupant responses in 15-18 km/h and 42 km/h rear sled tests. The effect of initial occupant posture is also discussed. Seven tests were conducted with lap-shoulder belted ATDs (anthropometric test device) placed on older and modern driver seats. Four tests were conducted with a 50th percentile male Hybrid III, two with 95th percentile male Hybrid III and one with a BioRID. The ATDs were ballasted to represent a Class I or II obese occupant in three tests. The tests were matched by seat model and sled velocity. The effect of occupant weight was assessed in three matches. The results indicated an increase in seatback deflection with increasing occupant weight.

Occupant protection in rear crashes is complex. While seatbelts and head restraints are effective in rear impacts, seatbacks offer the primary restraint component to front-seat occupants in rear impacts. Seatback deflection due to occupant loading can occur in a previous rear crash and/or in multiple-rear event crashes. Seatback deflection will in-turn affect the plastic seatback deformation and energy absorption capabilities of the seat. This study was conducted to provide information on seatback deflection and seat energy consumption in low and high-speed rear impacts. The results can be used to examine seatback deflection and energy consumed in a previous rear impact, or in collisions with multiple rear impacts. Prior seatback deflection and energy absorption can affect the total remaining energy absorption and seat performance for a subsequent rear impact.

Interest in rear-seat occupant safety has increased in recent years. Information relevant to rear-seat occupant interior space and kinematics are needed to evaluate injury risks in real-world accidents. This study was conducted to first assess the effect of size and restraint conditions, including belt misuse, on second-row occupant kinematics and to then document key clearance measurements for an Anthropomorphic Test Device (ATD) seated in the second row in modern vehicles from model years 2015-2020. Twenty-two tests were performed with non-instrumented ATDs; three with a 5th percentile female Hybrid III, 10 tests with a 10-year-old Hybrid III, and 9 tests with a 6-year-old Hybrid III. Test conditions included two sled bucks (mid-size car and sport utility vehicle (SUV)), two test speeds (56 and 64 km/h), and various restraint configurations (properly restrained and improperly restrained configurations). Head and knee trajectories were assessed.

A significant portion of real-world passenger vehicle side impacts occur at lower speeds than testing conducted by the National Highway Traffic Safety Administration (NHTSA) or the Insurance Institute for Highway Safety (IIHS). Test data from low- to moderate-speed side impacts involving late-model passenger vehicles is limited, making the evaluation of vehicle impact response, occupant loading, and injury potential challenging. This study provides the results of low- to moderate-speed impact testing involving a late-model mid-size sedan. Two full-scale Non-Deformable Moving Barrier (NDMB) side impact crash tests were conducted at speeds of 6.2 mph (10.0 kph) and 13.4 mph (21.6 kph). Instrumentation on the late-model sedan used for the test series included tri-axis accelerometers and seat belt load cells.

As a result of the development of Event Data Recorders (EDR) and the recent FMVSS regulation 49 CFR 563, today’s automobiles provide a limited subset of electronic data measurements of a vehicle’s state before and during a crash. Prior to this data, the only information available about the vehicle movements before or during a collision had come from physical evidence (e.g. tire marks), witnesses, aftermarket camera systems on vehicles, and ground-based cameras that were monitoring vehicle traffic or used for security surveillance. Today’s vehicles equipped with Advanced Driver Assistance Systems (ADAS) have vehicle-based sensors that measure information about the environment around a vehicle including other vehicles, pedestrians, and fixed wayside objects.

Studies of rollover accidents have reported crash attributes such as the number of rolls, rollout distance, initial over-the-ground speed, average roll rate, average over-the-ground deceleration, magnitude of roof deformation, cumulative damage, time and post-crash headroom. While these more general attributes are related to the repeated vehicle-to-ground impacts during a rollover, it has been previously shown [1] that a specific ground impact during a rollover and its consequences can be studied in more detail by using its acceleration time history (crash pulse or impulse) and energy loss. These two quantities are particularly meaningful to use when studying impact mechanics, however, they are limited to circumstances where the data exists, which means real-world on-road crashes cannot be used directly. Acceleration and energy data have been collected and previously published for three Subaru Forester dolly rollover tests, and have been studied in more detail in this writing.

Rear-end impacts are the most common crash scenario in the United States. Although automated vehicle (AV) technologies, such as frontal crash warning (FCW) and automatic emergency braking (AEB), are mitigating and preventing rear-end impacts, the technology is only gradually being introduced and currently has only limited effectiveness. Accordingly, there is a need to evaluate the current state of passive safety technologies, including the performance of seatbacks and head restraints. The objective of this study was to examine trends in head and neck loading during rear impact testing in new vehicle models over the prior decade. Data from 601 simulated rear impact sled tests (model years 2004 to 2018) conducted as a part of the Insurance Institute for Highway Safety (IIHS) Vehicle Seat/Head Restraint Evaluation Protocol were obtained.

Seatback strength and injury potential in moderate to high-speed rear-end collisions were investigated in a series of 12 HYGE sled tests. The test methodology included the use of instrumented Hybrid-III anthropomorphic test devices (ATDs). Four tests employed a 95th percentile male ATD ballasted to a total weight of 300 lbs and subjected to approximate 15 mph Delta-V impacts. The remaining tests employed an unmodified 50th percentile male ATD with impacts of approximately 25 mph Delta-V, and three ATD positions, including two "out of position" postures corresponding to leaning forward ("forward" position), and leaning forward and inboard ("radio" position). Seats from three different vehicles were tested, representing a range of strength values. Upper neck values for N were less than 1.0 in all cases. Lower neck N values sometimes exceeded 1.0 with the 50th percentile male ATD out of position, and these values did not trend with seatback strength.

This study reports pedal activation forces and typical acceleration and deceleration rates during everyday driving activities. Twenty subjects of varying ages, height and weight participated in the study. Each subject was asked to drive a four-door sedan along 2.3 miles of roadway in DuPage County, Illinois. Vehicle speed, acceleration, and position were measured using a global positioning system that was synchronized with force data collected from load cells rigidly mounted on the vehicle's accelerator and brake pedals. Pedal forces and vehicle behavior were measured during common driving tasks such as, shifting the transmission into reverse, backing out of a parking spot, and, making a right hand turn from a stop sign. Our data suggests that simple vehicle dynamic tasks produced in experimental settings may not reliably reproduce vehicle and occupant behavior.

Many published studies have characterized walking and running speeds of young children. However, there is a paucity of data on the cycling speeds of very young children (4 to 5 years old). The purpose of this study was to obtain an estimate of cycling speed for boys and girls both who are learning to ride bicycles (i.e., younger children who still ride with training wheels) and who have already learned to ride bicycles (i.e., slightly older children who no longer use training wheels). A sample of 32 child riders (17 boys, 15 girls; 17 four-year-olds who still ride with training wheels, 15 five-year-olds who do not) were asked to ride a short pre-defined distance at their usual speed when riding, and again at their highest speed. We found that while age and experience can differentiate riders, there were only small differences between boys’ and girls’ speeds in either age group.

This study was conducted to assess the effects of differing rear impact pulse characteristics on restraint performance, front-seat occupant kinematics, biomechanical responses, and seat yielding. Five rear sled tests were conducted at 40.2 km/h using a modern seat. The sled buck was representative of a generic sport utility vehicle. A 50th percentile Hybrid III ATD was used. The peak accelerations, acceleration profiles and durations were varied. Three of the pulses were selected based on published information and two were modeled to assess the effects of peak acceleration occurring early and later within the pulse duration using a front and rear biased trapezoidal characteristic shape. The seatback angle at maximum rearward deformation varied from 46 to 67 degrees. It was lowest in Pulse 1 which simulates an 80 km/h car-to-car rear impact.

Assessment of the physical evidence on a seat belt restraint system provides one source of data for determining an occupant’s seat belt use or non-use during a motor vehicle crash. The evidence typically associated with loading from a restrained occupant has been extensively researched and documented in the literature. However, evidence of loading to the restraint system can also be generated by other means, including the interaction of an unrestrained occupant with a stowed restraint system. The present study evaluates physical evidence on multiple stowed restraint systems generated via interaction with unrestrained occupants during a full-scale dolly rollover crash test of a large multiple passenger van. Unbelted anthropomorphic test devices (ATDs) were positioned in the driver and right front passenger seats and in all designated seating positions in the third, fourth, and fifth rows.

The biomechanical injury assessment for an occupant in a planar vehicle-to-vehicle collision often requires a kinematic analysis of impact-related occupant motion. This analysis becomes more complex when the collision force is eccentric to the center of gravity on a struck vehicle because the vehicle kinematics include both translation and potentially significant yaw rotational rates. This study examines the significance of vehicle yaw on occupant kinematics in eccentric (off-center) planar collisions. The paper describes the calculation of the instantaneous center of rotation (ICR) in a yawing vehicle post-impact and explores how mapping this quantity may inform an occupant’s trajectory when using a free particle “occupant” analysis. The study initially analyzed the impact-related occupant motion for all the outboard seat positions in a minivan using several hypothetical examples of eccentric vehicle-to-vehicle crash configurations with varying PDOF, delta-V, and yaw rate.

This research examines the effects of impactor characteristics on the calculated structural stiffness parameters A and B for the struck sides of late-model vehicles. This study was made possible by crash testing performed by the National Highway Traffic Safety Administration involving side impacts of the same vehicle line with both a rigid pole and with a moving deformable barrier. Twenty-nine crash test pairs were identified for 2018 model-year vehicles. Of 60 total tests, 49 were analyzed. Test data for 19 vehicles impacted in both modes resulted in A and B values considered to be valid. Classifying these 19 vehicles according to the categories defined by Siddall and Day, only Class 2 multipurpose vehicles were represented by enough vehicles (10) to search for trends within a given vehicle category. For these vehicles, more scatter in the results was observed in both A and B values for the MDB impacts compared to the pole impacts.

By their nature as chaotic, high-energy events, rollovers pose a high risk of injury to unrestrained occupants, in particular through exposure to projected perimeter contact and ejection. While seat belts have long been accepted as a highly effective means of retaining and restraining occupants in rollover crashes, it has been suggested that technologies such as laminated safety glazing or rollover-activated side curtain airbags (RSCAs) could alternatively provide effective occupant containment. In this study, a full-scale dolly rollover crash test was performed to assess the occupant containment capability of laminated side glazing and RSCAs in a high-severity rollover event. This allowed for the analysis of unrestrained occupant kinematics during interaction with laminated side glazing and RSCAs and evaluation of failure modes and limitations of laminated glazing and RSCAs as they relate to partial and complete ejection of unrestrained occupants.

This study assesses vehicle and occupant responses in six vehicle-to-vehicle high-speed rear impact crash tests conducted at the Exponent Test and Engineering Center. The struck vehicle delta Vs ranged from 32 to 76 km/h and the vehicle centerline offsets varied from 5.7 to 114 cm. Five of the six tests were conducted with Hybrid III ATDs (Anthropometric Test Device) with two tests using the 50th male belted in the driver seat, one test with an unbelted 50th male in the driver seat, one test with a 95th male belted in the driver seat, and one with the 5th female lap belted in the left rear seat. All tests included vehicle instrumentation and three tests included ATD instrumentation. The ATD responses were analyzed and compared to corresponding IARVs (injury assessment reference values). Ground-based and onboard vehicle videos were synchronized with the vehicle kinematic data and biomechanical responses.

In rear-end collisions, the seatback provides primary occupant restraint during initial rearward motion of the occupant relative to the vehicle interior as the vehicle is accelerated forward by collision forces. When properly used, seat belts contribute to limiting occupant excursion and loading by working in concert with the seatback, as well as managing forward excursion on rebound after rear-end impacts. A lack of data evaluating the role of seat belt restraint component technology in limiting occupant motion and loading during high-severity rear-end impacts has been identified. This knowledge gap is particularly apparent for occupants who are not seated normally, in position, at the time of impact. Previous static pretensioner deployment tests suggest that different combinations of latch plate design and pretensioner deployment strategies might have different effects on occupant restraint.