TThe in-crash model estimates occupant injury responses during a car-to-car collision. It considers factors such as the initial seating position (e.g., head position), collision configuration (impact speed, angle, and offset), and restraint system parameters, including airbag deployment timing and vent size, as well as seatbelt pretensioner timing and load limit. The surrogate model predicts key injury metrics such as the Head Injury Criterion (HIC) and chest deflection, providing a fast approximation of occupant safety performance under varying crash conditions.