At what cost? How planned collisions with pedestrians may save lives.

At what cost? How planned collisions with pedestrians may save lives. Accid Anal Prev. 2020 Apr 16;141:105492 Authors: Robinson MD, Beal CE, Brennan SN Abstract Pedestrian avoidance algorithms often tacitly assume that the maneuver which minimizes collisions will also be the safest maneuver. This work shows that this is not always the case when considering pedestrian fatalities. Given the unavoidable uncertainty in vehicle motion, environmental parameters, and pedestrian behavior, emergency avoidance maneuvers often involve some chance of a collision. Maneuvers that aim to keep the vehicle as far away from the pedestrian as possible will theoretically minimize collisions; but if this strategy is followed and a collision occurs nonetheless, it will often be at a higher speed than would occur with alternative strategies. This is a result of the tires' friction ellipse which enforces a constraint between steering versus braking; for collision avoidance, braking must be reduced if pedestrian clearance is to be maximized. This work shows that in some common pedestrian collision situations, the net effect of this increase in vehicle speed for pure avoidance offsets the benefits of reducing collisions. Pedestrians, if hit, would be hit at higher speeds leading to a net reduction in pedestrian survivability for collision-minimizing maneuvers. First, this trend is demonstrated and explained using a simplified point-mass model of a vehicle, wh...
Source: Accident; Analysis and Prevention. - Category: Accident Prevention Authors: Tags: Accid Anal Prev Source Type: research