A pedestrian struck by a car is not one collision. It is a sequence, and the order of the blows decides who lives.
The wrap
With an ordinary sedan, the bumper meets the legs first, below the body's center of mass. The legs are knocked out from under the person while the upper body rotates toward the car. The pelvis and thigh catch the leading edge of the hood, and the torso and head come down onto the hood or the windshield. That is the wrap, and the head striking the vehicle is often the most violent contact of the whole event. It is not always the last.
The ground
After the wrap, the body is thrown, and it meets the pavement. An unprotected head hitting asphalt behaves like a fall from a height, and that second impact is frequently the fatal one. It is why the ground, not the bumper, is so often where the death is written.
Height changes the sequence
A tall, blunt front end changes all of it. A pickup or a large SUV strikes at or above the center of mass, so the body does not ride up onto the hood. It is knocked down and forward, and the danger shifts to being carried under the vehicle and over the wheels. Same speed, different sequence, higher chance of death.
Speed is the multiplier
Speed does not add risk, it multiplies it. The energy of the strike and the distance the body is thrown climb with the square of the impact speed, and the survival curve is not a straight line. Risk rises slowly to about twenty miles per hour and then climbs steeply, so the difference between a twenty-five and a forty mile per hour strike is the difference between a hospital and a coroner.
Reading it backward
Because each stage leaves its own marks, a reconstruction can read the collision in reverse. The injuries on the body, the damage on the vehicle, and the distance the person was thrown let an expert estimate the impact speed and tell a wrap from a forward projection. The sequence is not a mystery. It is evidence.
The lesson
A pedestrian strike is not one moment. It is a chain, and knowing which link did the harm is the difference between a story and a case.
On impact speed and a pedestrian's risk of severe injury or death, see the AAA Foundation for Traffic Safety study. On front-end height and injury outcomes, see the peer-reviewed work on vehicle front-end geometry (PubMed). This is general information, not medical or legal advice.
