The trajectories of pedestrians, motorcycles, motorcyclists, etc., following a road accident

Searle, John A.<sup>1</sup>; Searle, Angela<sup>1</sup>

Affiliations

Abstract

For many years accident investigators have been faced by the problem of estimating the projection velocity associated with a given trajectory. The most recent contributions to this topic were two papers at the 1981 AAAM but these, like earlier work, deal only with the aerial part of the trajectory, until the object first lands. In most accidents however the point of first landing cannot be determined and it is the point at which the object comes to rest which is recorded.

The present paper derives an equation for the projection velocity associated with a given total trajectory. Using this equation it is possible to bracket the limits within which the projection velocity must lie, even when the angle of projection is unknown. In order to facilitate the use of this approach, data have been obtained on the frictional coefficients.

This information is compared with existing field data on pedestrian trajectories. It is found that these pedestrian trajectories correspond to only a percentage of the full velocity of the vehicle. This percentage is large for children struck by vehicles with high front ends, approaching 100%,but is significantly less for adults and for vehicles with low fronts.

Links

DOI: 10.4271/831622

SAE: 831622

Cited By (6)

Year	Entry
2005	Depriester J-P, Perrin C, Serre T, Chalandon S. Comparison of several methods for real pedestrian accident reconstruction. In: Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 6-9, 2005; Washington, DC.
2015	Guillaume A, Hermitte T, Hervé V, Fricheteau R. Car or ground: which causes more pedestrian injuries? In: Proceedings of the 24th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 8-11, 2015; Gothenburg, Sweden.
1985	Costanzo A. General problems concerning car-pedestrian collision. In: Proceedings of the 10th International Technical Conference on Experimental Safety Vehicles (ESV). July 1-4, 1985; Oxford, England.943-948. SAE 856109.
1995	Anderson RWG, McLean AJ, Farmer MJB, Lee BH, Brooks CG. Vehicle travel speeds and the incidence of fatal pedestrian crashes. In: Proceedings of the 1995 International IRCOBI Conference on the Biomechanics of Impact. September 13-15, 1995; Brunnen, Switzerland.107-117.
2012	Piantini S, Grassi D, Mangini M, Pierini M, Spina R, Peris A. Pilot study of an integrated accident research system based on a medical and engineering data in the metropolitan area of Florence. In: Proceedings of the 2012 International IRCOBI Conference on the Biomechanics of Injury. September 12-14, 2012; Dublin, Ireland.10-21.
2023	Halari MM. The Significance of Injuries and Anatomical Patterns of Trauma in Pedestrian and Cyclist Fatalities and Their Association With Motor Vehicle Collision Dynamics and Post-Collision Kinematics [PhD thesis]. University of Western Ontario; 2023.