The front of a car has three feet to save you. The door has three inches.
Where the crush space is, and is not
A head-on crash meets the engine and the front structure, feet of steel engineered to fold and absorb energy before it reaches you. A crash into the side meets a door, a window, and a pillar, inches of space between the outside of the car and the person inside. Same closing speed, almost none of the cushion.
Why the turn across traffic is the classic setup
A left turn across oncoming traffic, or a failure to yield at an intersection, puts two vehicles into each other at an angle, and angled crashes load the side. The near-side occupant, the one on the struck side, takes the worst of it, because the door, the pillar, and the striking vehicle all reach the body nearly together. There is no fold, only intrusion.
The judgment behind the turn
Turning safely across a gap is a perception task done in about a second: estimating an oncoming vehicle's speed and distance and your own acceleration. That estimate leans on contrast and motion perception, and both fall off with age and with rain, glare, and dusk. Failed to yield and turned into the path of are often not recklessness but a misjudged gap.
What the injury pattern tells you
Because the force comes from the side, the injuries cluster there, the chest, the pelvis, the head against the intruding structure. That pattern is a fingerprint of direction, and it lets a reconstruction say where the force came from and how much.
The lesson
A side impact is not a lesser crash. It is the same energy meeting the one part of the car with nowhere to put it.
On side-impact injury, near-side occupants, and the limits of side protection, see Biomechanics of side impact (PMC). This is general information, not medical or legal advice.
