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Recent models of General Motors (GM) and selected Ford vehicles may be equipped with an event data recorder (EDR) that records information in the airbag sensing and diagnostic module (GM-SDM) or restraint control module (Ford-RCM). These systems have become a resource to the accident reconstructionist in the analysis of collisions involving data recorder equipped vehicles, as typically the data can be downloaded via the Vetronix Crash Data Retrieval (CDR) System. The purpose of this paper is to investigate the use of the CDR System in pedestrian accidents. A series of impacts using a pedestrian dummy and SDM equipped vehicles were performed. After each test, the SDM was downloaded via the CDR system and the data evaluated. The dummy and vehicle kinematics were documented and the vehicle impact response was compared with the SDM recorded velocity change and impact speed.

A search of the automotive collision trauma literature reveals that over the last 35 years shows that there have been less than ten published Society of Automotive Engineers (SAE) articles describing the collision effects and resulting human occupant kinematics in low speed side impact collisions. The aim of this study was to quantify the occupant response for both male and female occupants for a battery of low-speed side impacts with various impact speeds and configurations. Eight volunteers were used in a series of twenty-five staged side impact collisions with impact speeds ranging from approximately 2 km/h to 10 km/h and impact configurations to the front, middle and rear side portions of the vehicle. A NHTSA FMVSS 301 moving barrier was used as the impacting vehicle. A stiff bumper was constructed to fit the front of the barrier and was attached at a normal passenger vehicle bumper height. Occupant and vehicle responses were monitored by accelerometers and high-speed video.

Pedestrian crash kinematics have been well documented for automobile versus pedestrian collisions. However, there is not significant amount of data concerning impact of pedestrians with a high profile vehicle. A series of pedestrian crash tests using full-sized vans was performed to add to the existing database of forward projection pedestrian collisions and to compare the crash test data to existing forward throw equations. The aim of this study was to examine the trajectory behavior of the pedestrian in a forward projection impact and the effect of different friction-value surfaces when applying a pedestrian model to the data. In performing the tests, the pedestrian dummy was stabilized using an 18.2 kg tensile strength monofilament wire hanging from a cantilever beam. The impacting vans were instrumented with a triaxial accelerometer triggered at impact with the dummy. Several testing surfaces were used, ranging from dry asphalt to a skidpad with > 1/16th inch depth of water.

Pedestrian collisions are primarily a disease of urban streets and intersections, where both pedestrian and automobile traffic are in high volume. City engineers and planners are plagued with the problem of mitigating the number of pedestrian/vehicle collisions while maintaining traffic flow. In an attempt to study the problem in depth, city engineers in Helsinki, Finland placed a camera in a bus station clock tower overlooking a busy downtown intersection in February of 1991. The camera was placed at the intersection to study pedestrian and vehicle behavior at the intersection and to quantify the speeds of the respective parties. Since its installation, the camera has witnessed fifteen pedestrian/vehicle accidents. Detailed measurements of the intersection were taken for analysis of the accidents. The intersection was also calibrated with the camera in place for use of the digitizing system.

Considerable research has been conducted over the past decade on the response of both vehicles and occupants to low speed rear impacts. This research has employed various conditions of target vehicle braking and target occupant awareness. Relatively little effort has been devoted to quantitatively comparing vehicle and occupant responses under different braking and awareness. Given the variety of potential braking and awareness conditions in actual rear impacts, it is desirable to better understand the influence of these reactions on both vehicle and occupant dynamics. Low speed vehicle-to-vehicle rear end collisions were conducted with instrumented vehicles and an instrumented human subject. Six conditions were evaluated: 1) unaware occupant without braking, 2) aware occupant without braking 3) unaware occupant braking “normally”, 4) aware occupant full-braking, 5) unaware occupant with brakes mechanically fully applied, and 6) aware occupant with brakes mechanically fully applied.

After an accident has occurred, there are a minimal number of low speed crash tests to assist the accident reconstructionist/engineer in determining the speed of a vehicle from little or no visible vehicle damage. Injuries are being documented by individuals as occurring in relatively low speed collisions. Yet, the impact speeds that have been taught to cause little or no damage do not suggest that injuries should have occurred at these correspondingly low G-forces. No comparison of the injury versus vehicle speed will be done in this paper; that is left to the biomechanical engineers and physicians. The purpose of this paper is to examine the issue of low speed impacts and the corresponding damage or shock isolator movement to the vehicle. For the purpose of this paper a low speed collision is an in line impact at a speed below 6 m/s.

Accident investigators rely on a wide range of methods to measure or quantify vehicle braking deceleration. Generally, this information is applied to define a “drag factor” or “coefficient of friction” for a skidding vehicle. Methods employed can include everything from simple estimations based on past experience and individual expertise to testing using sophisticated devices. This paper is a compilation of data from a series of skid tests comparing some of the methods and equipment currently available. These tests were performed with an assortment of vehicles each equipped with or monitored by a selection of devices designed/applied to quantify some combination of time, distance and velocity. The devices tested include two models of “fifth wheels,” the Vericom VC2000, the g-analyst, a bumper detonator and shot timer, doppler RADAR, an infrared timer device, and a drag sled. The data from each of these skid tests is then provided for the reader's comparison and analysis.

A pedestrian involved traffic collision is generally less fully understood than the “typical” car-to-car broadside intersection collision. For this reason, the analysis of the pedestrian involved collision is, in many respects, more complicated and demanding. This paper addresses the typical sequence of events in a pedestrian involved collision and the movement of the vehicle and pedestrian body from pre-impact through the collision to their final points of rest. Methods for the analysis of the pedestrian involved collision, including a review of several different techniques for calculating vehicle impact velocity are also presented. A comparison of crash test data to different forms of analysis is provided as a frame of reference for the reader in evaluating these methods.

Determining the impact velocity of a striking vehicle in a bicycle-involved collision is arguably the most difficult part of preparing an analysis or reconstruction of such an event. To help the accident reconstructionist in this effort, a series of crash tests were conducted to relate the impact velocity of the striking vehicle to the throw distance for the cyclist. This series of tests was conducted using a 1984 four-door Toyota Corolla and an articulated dummy astride a group of similar bicycles. The dummy/bicycle arrangement was struck at velocities ranging from 16 to 27 mph (25 to 43 km/hD3) relative to the cyclist.