Vehicle control system and vehicle control method

A vehicle control method utilizing a vehicle control system, the vehicle control system including a vehicle capable of traveling in a measurement target area, a travel controller which controls travel of the vehicle, and a position measurement portion which measures a position of the vehicle within the measurement target area and positions of a plurality of interfering objects within the measurement target area, wherein the travel controller is configured to control travel of the vehicle based on position information of the vehicle in the measurement target area and position information of the plurality of the interfering objects, measured by the position measurement portion, wherein the position measurement portion is configured to manage the measurement target area by dividing the measurement target area into a plurality of section areas, and is configured to manage an intra-area interfering object number, which is the number of interfering objects in a section area, independently for each of the plurality of the section areas, the travel vehicle control method comprising the following steps that are performed by the travel controller:

• a travel control step in which travel of the vehicle is controlled in any one of a plurality of travel modes;
• a congested state determining step in which whether the section area is in a congested state, in which the intra-area interfering object number is greater than a set upper limit number, is determined independently for each of the plurality of section areas, based on the measurement information from the position measurement portion,
• wherein, in the travel control step, a normal travel mode is selected as the travel mode when the vehicle is about to be caused to travel in the section area that is determined to be not in the congested state, and a congested area travel mode is selected as the travel mode when the vehicle is about to be caused to travel in the section area that is determined to be in the congested state, and
• in the travel control step, in the congested area travel mode, an upper limit travel speed for the vehicle is set to a congestion upper limit travel speed which is less than an upper limit travel speed in the normal travel mode.