What is not a proven reason why drivers may unintentionally steer in the direction of their gaze?

Drivers often have a tendency to steer in the direction in which they are looking, a behavior that can lead to unintentional lane departures or collisions. Emergency lighting is primarily designed to alert drivers to hazards, which can draw their attention. While it may influence driver focus and response to an incident, it does not inherently cause drivers to steer in a specific direction simply based on where they are looking.

On the other hand, road conditions can significantly impact how a vehicle handles and may change a driver's gaze to required focal points for navigation, thereby influencing steering. The emotional state of a driver affects their level of awareness and response to driving conditions, which can also lead to a gaze-induced steering reaction. Lastly, vehicle maneuverability refers to how easy it is for a vehicle to change direction, which could be affected by various factors including the driver’s focus.

Thus, among the choices provided, emergency lighting does not directly explain the propensity for drivers to steer toward their gaze, making it the least likely explanation for this behavior.