How do vehicles protect occupants in side impacts?

Side impact protection uses multiple strategies: Reinforced door structures with impact beams, B-pillar reinforcement with high-strength steel, padded interior surfaces to reduce head injury, side airbags and curtain airbags, seat-mounted pelvic airbags, and robust rocker/sill structures. Since side impact intrusion distance is limited (no crumple zone like frontal), the focus is on strong structures to prevent intrusion and airbags to cushion occupant contact with intruding surfaces.