Pedestrian Speed from Vehicle Damage

More information

Main author

Colin Glynn; Denis P. Wood

Co-Authors

-

Type of media

PDF

Publication type

Lecture

Publication year

2015

Publisher

24. EVU Conference, Edinburgh

Citation

-

In car to pedestrian collisions the pedestrian speed can be a crucial determinant in the potential for the driver to carry out an avoidance manoeuvre. In many such collisions there is permanent contact damage to the vehicle due to the primary impact from the pedestrian’s leg/lower body and the secondary impact from the pedestrian’s head. It has been shown that a linear relationship exists between the ratio of the transverse to longitudinal vehicle damage offsets (H/L) and the ratio of the pedestrian speed to car speed (Vp/Vc). Madymo modelling has shown that the pedestrian stance (stage within the pedestrian gait cycle) has a strong influence on the movement of the pedestrian during the collision; with the struck leg leading the pedestrian will rotate such that the rear of the pedestrian is presented to the car while with the struck leg lagging the front of the pedestrian is presented. As such, it has been shown that the head contact location can be used to determine whether the pedestrian’s struck leg was leading or lagging. A Constant Inertial Property (CIP) pedestrian model has been applied in a Monte Carlo environment to develop linear relationships between Vp/Vc and H/L for the cases where the struck leg is leading, lagging or the struck leg position is unknown. Knowledge of the car speed allows the pedestrian speed to be estimated. The case where there is no transverse offset between primary and secondary damage locations, often incorrectly used as support for the conclusion that the pedestrian was stationary at impact, is analysed.

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