The safety of buses is crucial due to its large proportion of the public transportation. To improve the bus safety level, especially avoiding the driver’s error which is the key factor of traffic accidents, an intelligent bus named iBus is designed. Unlike other self-driving vehicles which are either in manual driving mode or self-driving mode, a dual control mode is also available in iBus. The dual control authority between drivers and machines makes the control and fault tolerant problem more challenging. In this paper, a novel architecture of self-driving system is proposed to improve the robustness, such as to the failure of hardware, including sensors and controllers. The mechanism of online hot backup is designed to enhance the reliability of the control system. A software monitor is implemented to ensure all the software modules work properly. To validate the feasibility of the whole system, the real-world road tests were conducted. The experimental results showed the reliability and robustness of the iBus.