Cruise control device for a vehicle

A cruise control system for an automotive vehicle controls a speed of own vehicle estimating conditions not only when the own vehicle passes through the intersection but also when the preceding vehicle passes through the intersection, for permitting travel on the ordinary road with a given distance. The cruise control system includes traffic signal characteristics obtaining means (1) for obtaining characteristics Cs of a traffic signal ahead, road information obtaining means (2) for obtaining intersection information including a distance L to an intersection, intersection arrival time calculating means (3) for calculating arrival timing of the own vehicle and the preceding vehicle on the basis of a distance L to the intersection, an own vehicle speed and a preceding vehicle travelling condition, traffic signal condition estimating means (4) for estimating the condition of the traffic signal on the basis of the traffic signal characteristics Cs and the intersection arriving time and control content modifying means (5) for modifying a content of cruise control of the own vehicle depending upon the estimated traffic signal condition.