Background and persistence of fibers on vehicle seat belts

Abstract

Examination of the fibers transferred to vehicle seats and seat belts makes it possible to establish links in cases of vehicle theft or road accidents. Unlike seats, seat belts often have fibers that are fused to them owing to the significant forces encountered in the event of an accident, fibers that can be evaluated for their persistence and significant probative value. The aim of the project is to determine the background fiber population naturally present on seat belts, as well as to carry out simulations to study the persistence of the fibers. These were determined using zonal samples from seat belts of ten different vehicles. For the experiments, drivers of the vehicles had to wear a luminescent T-shirt for a total of 30 min, then remove it and continue driving normally for variable periods of time. The results show that the persistence of fibers on seat belts is heavily influenced by the number of times the driver fastened/unfastened their seat belt. The background population of fibers is comparable to the literature but can show important deviations when specific clothes are worn by the driver (i.e., winter accessories).