Adaptive cruise control apparatus and method of operating adaptive cruise control in consideration of traffic condition

An adaptive cruise control apparatus, comprising:

• a sensor device for acquiring information on vehicles around a subject vehicle including information on a distance between a forward vehicle and the subject vehicle, and information on a speed of the forward vehicle and a speed of a nearby vehicle traveling in an adjacent lane to a lane of travel of the subject vehicle;
• and
• a controller for calculating an acceleration of the subject vehicle based on the information on vehicles around the subject vehicle, determining a traffic condition around the subject vehicle based on the information on vehicles around the subject vehicle, limiting the acceleration of the subject vehicle according to the determined traffic condition, and controlling a power train of the subject vehicle according to the limited acceleration,
• wherein the controller determines that the traffic condition around the subject vehicle is congested according to at least one method of a first method and a second method,
• wherein the first method is based on an average speed of the forward vehicle, a predetermined first reference speed, a number of times the forward vehicle stops, and a predetermined number of stops during a predetermined reference time, and
• wherein the second method is based on an average speed of the nearby vehicles around the subject vehicle and a first predetermined percentage of an average speed of the forward vehicle during the predetermined reference time.