Each year, many cars (in Poland approximately three hundred) are adopted for disabled driver, to enable them to drive the car independently. The purpose of the paper is to assess the key factors which significantly influence the disabled driver behavior during a frontal crash and have the biggest impact on the safety factors. Methods: To achieve the purpose of the paper, the finite element method was used. The authors built the numerical model which includes operation of all safety systems operating in the real car (sensors, seat belts, airbag). Using this method, the authors simulated few different cases of the frontal crash of the car driven by a person with disabilities. Results: The obtained results were: displacements, velocities and accelerations of the head, pelvis and shoulders. Additional results were also loads in the neck. Based on the achieved results, several biomechanical parameters and criterions (HIC, Nij) were computed. Conclusions: Therefore, during car adaptation for disabled drivers using a four-point seat belts system, this parameter can be optimized to reduce forces acting on the driver chest. Higher values of the force limit reduce Nij and increase HIC and contact forces between the dummy and seatbelts. Therefore, during designing of the pyrotechnic four-point seat belts system, the pretensioner characteristics should be analyzed taking all the driver’s biomechanical parameters into account.