Search Results

Despite efforts by industry to reduce the problem of injury in rear impacts, there continues to be a large number of such claims. This is true even in low speed impacts which result in little or no damage to the vehicles involved. Recent studies of such incidents have been described in the literature. These studies have concentrated primarily on simple bumper to bumper impacts where the front bumper of the striking vehicle contacts the rear bumper of the struck vehicle. Perhaps a more common type of rear impact is one in which the bumper of the striking vehicle rides over or under the rear bumper of the struck vehicle. The heavy truck to car rear impact is an example of an overriding impact. This paper describes several staged impacts of this type in which vehicle and occupant responses were measured using fully instrumented Hybrid III dummies or human volunteers.

A Computer Accident Simulation (CAS) is the application of dynamics to known physical evidence to yield a best approximation of the interactions of vehicles and other objects during the real world accident scenario. The simulation is based upon the reconstruction after an engineer's examination of the vehicles involved, the roadway (i.e., skid marks and gouges), and any substantiated evidence from witnesses. Examples of various cases are presented to illustrate the engineer's accident reconstruction and how the reconstruction is used to establish the computer simulation. The cases are used to explain the accuracy, features, advantages, and disadvantages of developing a computer accident simulation. During the interaction of the engineer and the graphics specialist, extra information such as witness viewpoint needs to be attained to make the computer simulation.

The discernment of whether a tire mark on a roadway is the result of a skidding tire or is the result of the rotation of the vehicle with unlocked wheels is important in vehicular accident reconstruction analysis. Resolution of the tire marks left by a vehicle after skidding and/or yawing on dry asphalt were experimentally studied for their similarities and differences under controlled test conditions. This paper analyses the results of this study and shows pictorially the differences for use by the accident reconstructionist. Analytical discussion are also presented that illustrate speed determination as estimated from yaw markings on the roadway.

The use of vehicle damage measurements has been proven to be an effective technique in the determination of impact energy and pre-collision speeds. However, as with any analytical technique, the quality of the speed estimate is highly dependent on the accuracy of the measurements. This relationship suggests a need to employ intricate and exacting measurement schemes to obtain useable data. This approach is often difficult to implement in a routine accident investigation where a tape measure may be the only available measuring device. In the current study, vehicle damage resulting from collisions with a known speed is measured with techniques of increasing sophistication and the results are compared. These measurements are then used in conjunction with the CRASH III computer program to estimate the pre-impact vehicle speeds. The analysis technique used by CRASH III is also reviewed to provide a summary understanding of how the crush measurements are used in the program.