In recent years, AEBS (Autonomous Emergency Braking System) has been put to practical use by various automotive companies. This system detects the front obstacle by using a camera or a laser and then brakes an automotive automatically. However, the load on the occupants is not considered in the current AEBS. On the other hand, increase of aged drivers has become an issue to be considered in the effort of enhancing safety performance of vehicle collision avoidance system. In order to solve this issue, we proposed a control system design model that can take into account the driver behavior during braking. Although, the new problem that the collision avoidance performance deteriorates so as to close an obstacle by the deceleration control using stationary LQR (Linear Quadratic Regulator) has been confirmed. Therefore, this study verifies an effectiveness of the vehicle deceleration control system using the time-varying feedback control. Moreover, we compared the performance of four methods for the load on driver and braking distance. The simulation results show that the proposed method can reduce the load on the driver and improve the collision avoidance performance.