When a rider goes over a freeway wall, the wall is not what kills him. The ground below it is. The wall only decided which way he was facing when he left.
Start with what a barrier does to a car, because the contrast is the lesson. A car meets the wall with a bumper and a fender, low, and the wall’s sloped face lifts and turns it. The car’s mass is one mass; it tracks along the concrete, sheds speed against it, and comes back into the lane. The person inside is belted to that mass and rides it out. That is the event the wall was tested for, and in the test the person is a seat inside the cabin, never a body in the air.
A motorcycle meets the wall low too. The machine is stopped or deflected. The rider is not part of the machine. He is sitting on it, held there by nothing but his hands and his balance, with his hips at about the height of the top of the wall and his torso and head above it. When the machine stops, he does what every unrestrained object does in a crash: he keeps going, at the speed and in the direction he had a tenth of a second before. On a straight road that direction is along the wall, and he slides. On a curve the machine was turning and he was not yet, so the direction is across the wall, and he goes over. The research on barrier crashes is blunt about which is worse. A rider thrown from the machine after the impact has significantly higher odds of serious injury than one who stays with it.
Now the air. Once the body clears the wall it is a projectile, and a projectile does not care what it was doing before. It cares about two things: how far it falls and how it is oriented when it lands. Gravity adds speed every foot of the way down, roughly a sprinter’s pace after ten feet, a neighborhood speed limit after twenty, a city boulevard after forty, and that speed is added to whatever forward motion the body left the wall with. An elevated ramp in a Texas city stands well above the roadway or the parking lot beneath it, often twenty feet and more. The rider who left the wall at a survivable speed arrives at the ground at one that is not.
The landing is where the medicine is. A body that meets the ground from height stops in the space of a few inches, and everything inside it keeps moving until something stops it. The trauma literature on falls from height sorts patients by the distance they fell, and the pattern holds across every study: the higher the fall, the more the chest is involved. In one series, chest injury was present in about four of ten patients who fell from ten to twenty feet, and in more than eight of ten who fell from thirty feet or more, with pelvic fractures rising the same way and deaths several times more likely in the higher groups. Chest injury is one of the leading causes of death in trauma, and in a fall it is blunt: ribs that break and flail, lungs that bruise and fill, and the great vessel behind the heart that tears where its moving part is tied to its fixed part, the same deceleration injury described in The Third Collision. The head takes its share too, and a helmet that did its work against the wall is not designed for a second, harder impact against pavement.
Understand what this does to the usual argument, because it will be made. He was speeding. He hit the wall at seventy. Speed at the wall matters, and it will be counted against him in a Texas court. But speed at the wall is not what the autopsy records. The autopsy records the fall, and the fall was chosen by the height of the structure and the height of the wall on it, neither of which the rider chose. A rider who meets a wall at forty on level ground slides and often lives. The same rider, at the same forty, on a ramp thirty feet in the air, goes over and dies of the landing. The difference between those two outcomes is not in the rider. It is in the road.
So build it in order, as always. The reconstructionist gives you the speed and angle at the wall from the machine’s damage and the marks on the concrete, and the trajectory from where the body came to rest. The department’s plans give you the height of the structure and the wall. The medical examiner’s report gives you the injuries of the landing, chest and pelvis and head, and separates them from the abrasions of the wall. Put those side by side and the jury sees what the wall saw: a machine it stopped, and a person it never touched.
On the physics of falls, the fall-height groups, and the chest and pelvis figures, see Nau, Leiblein, Verboket, Hörauf, Sturm, Marzi and Störmann, Falls from Great Heights: Risk to Sustain Severe Thoracic and Pelvic Injuries Increases with Height of the Fall, Journal of Clinical Medicine 10(11):2307 (2021), whose groups were three to six meters, seven to nine, and above nine. On blunt chest trauma, flail chest, pulmonary contusion, and deceleration injury to the heart and aorta, see Jain and Waseem, Thoracic Trauma (StatPearls, National Library of Medicine, updated Feb. 2026). On rider ejection after barrier impact, see Daniello, Injury Mechanisms in Roadside Motorcycle Collisions (Virginia Tech, 2013). The engineering of the wall itself is in Redirect; the impact speeds from height are the ordinary free-fall figures, rounded. General information, not medical or legal advice.
