One way to estimate the degree of realism of the simulator is to run experiments that have been performed in the real world and compare the results. Experiments recording eye movements of human drivers [Land94] show that for the task of road following, humans rely particularly on the tangent point on the inside of each curve, fixating it 1-2 seconds before issuing the steering command and constantly returning the gaze to it during the maneuver. The main reason for this is that the lateral position of the tangent point with respect to the current heading of the vehicle gives a good indication of the curvature of the road ahead, and therefore it can be used directly in the steering control loop.
Another finding was that humans are switching among several tasks (eg. to fixate other relevant places in the visual field), which is essential for driving in complex environments such as city streets.
A similar behavior was noticed for human subjects in our driving simulator. In the following videos, the white circle in each frame indicates the gaze direction.