It is well-documented that when negotiating winding¹ roads, drivers tend to look at a specific, well-defined point on the lane marking — referred to as the tangent point（切点） . New research finds that the further drivers can look ahead, generally in left-hand curves, wide curves and when leaving a curve, the less they have to look at the tangent point. Alternatively, when drivers enter or maneuver²（机动，调遣） through a right-bound curve, where they see less roadway ahead, they will spend more time looking at the tangent point. These findings are reported in a recently published article, "Car drivers attend to different gaze targets when negotiating closed vs. open bends," in the Journal of Vision.

"The ultimate goal of the project is to build a device into cars that warns the driver if he is in danger of unintentionally（无意地） departing from the lane," says author Farid I. Kandil of the Department of Psychology³, University of Münster, Germany.

In the study, six drivers test-drove a car repeatedly through a series of 12 right- and left-hand bends, or curves, on real roads while their eye movements were recorded. The results confirmed that when moving into a curve, drivers rely heavily on using the tangent point before turning the steering⁴ wheel. The findings further revealed that a driver will look at the tangent point 80 percent of the time when there is a shorter sight distance, such as with sharp, right-hand curves. In open bends such as left-hand curves, and when leaving curves, drivers spent a third of their time looking at the end of the curve and the straight road that comes after.

The experiments were conducted in right-hand traffic as in continental⁵ Europe and the United States. According to the researchers, there are many hints suggesting that the results can also be used to predict how drivers negotiate curves in left-hand traffic.

"The system we envision will look out for（设法得到，留心） upcoming curves and retrieve⁶ information about the eye movements the driver normally performs," explains Kandil. "If the driver does not show his typical pattern of eye movements upon approaching a bend, then the system will assume that he has not seen it and will warn him in time."

The research team plans to conduct additional experiments, using a prototype to determine whether the warning system provides enough time for the driver to react properly.