In trying to develop a model for driver behaviour we think it will be suitable to repersent the different features of a road environment as obstacles, which a driver needs to avoid in order to reach his destination safeley. Further, the driver would like to avoid these obstacles in such a manner, so that his speed is not impeded to a large extent.A subsidiary task is to develop a procedure which will suggest a feasible position on road for the driver.

The theory of robot motion planning based on potential field approach comes in extremely useful while trying to develop a model of driver behaviour on the lines described above. In this approach, a robot's path in an area strewn with obstacles is determined. The features of determination of such a path, which are relevant to the proposed principle of modelling driver behaviour are as follows:

Each obstacle is assumed to emit a repulsive force around it.This repulsive force is termed as a potential field and can be thought as a means of qualifying the threat posed by the obstacle to the movement of robot.
Any point in the area, where the robot can possibly move is assumed to possess a potential.This potential is the sum total of the potentials at that point due to all the obstacles in the area.
The robot selects the next point to move to by determining which of the points has the least potential.
The velocity of the robot depends on the potential of the position occupied by it. Higher is the potential, nearer the object is to the goal and hence lower should be its speed.
The Path of the robot is obtained by joining such paths.