Shared control is a control framework in which control action is shared between a human driver and an automation. In this work, the shared control is studied based on game theoretical approach of distributed model predictive control (DMPC). The solution of cooperative game is derived under DMPC framework, and then realistic driving situation is studied in cooperative game framework. Shared control strategy for fully mixed driving authority is proposed considering collision probability based on TTC (time to collision) and tracking error. Simulations were conducted using Matlab/Simulik in cooperative driving. The simulation scenarios consist of safety critical situation and non-safety critical situation. In safety critical situation, an automation takes more control authority to avoid a collision, and in non-safety critical situation a human driver takes more control authority. The simulation results show that the control authority is shared continuously by the proposed shared control strategy.