The self-propelled vehicle system includes a drive line, a start marker, and a self-propelled vehicle. The self-propelled vehicle includes a plurality of drive line sensors arranged, in a direction intersecting with the travel direction of the self-propelled vehicle, at a wider range than a width of the drive line, a marker sensor that detects the start marker, and a control unit. After the start marker is detected by the marker sensor, the control unit nullifies the detection output of one group of the drive line sensors out of a plurality of groups that are formed by dividing all the drive line sensors, and in accordance with the detection output of another of the groups, the control unit makes the travel direction of the self-propelled vehicle follow the drive line branched towards a side of the another group, which is one of the two drive lines branched into two directions.