We wish to decrease traffic accidents and want to observe drivers' behaviors to find ways to drive safely. Observations at the real environment include many risks to have needless but critical accidents. Using a car driving simulator, we can observe drivers' behaviors in dangerous situations safely. We constructed an immersive car driving simulator. We conducted an experiment in this immersive environment. The task was that a driver turned a car to the right in the virtual course. The numbers of subjects were one in a real environment and six in a virtual environment. We observed a common behavior of a driver in both environment, two common behaviors of six drivers in virtual environment and two individual variations from six drivers in virtual environment. Our immersive car simulator worked as a simulation of a real driving situation.