In a vehicle operation assist control system for assisting a vehicle operator to operate a vehicle, a distance to the obstacle and a width of the obstacle are detected by a radar or the like, and, when an obstacle is detected, the system determines an evasion path and accordingly modifies the map information available to the system. Therefore, the system, being aware of the situation, would not interfere with the vehicle operator taking an evasive action. The evasive path may be defined as a curvature which changes as a sinusoidal mathematical function of the position of the vehicle along the path. The control system may be based on a yaw rate control or a vehicle side slip angle control.