The purpose of this study was to decrease the labor demands of vegetable harvesting by automatically controlling the vegetable carrier. We developed a prototype of a carrier that had a simple mechanism, but possessed enough functions to follow a vegetable harvester smoothly. The following system automatically controlled starting, acceleration, deceleration, and steering. It was able to follow a cabbage harvester up to a running speed of 0.4 m/s in a performance test on asphalt. It could follow a Welsh onion harvester at 0.02 to 0.04 m/s while providing an effective field capacity of 0.4 to 0.6 a/person?h. The effective field capacity was equal to that of conventional work, but with 20% fewer working hours (e.g., transferring and taking the harvest out). Additionally, the worker did not need to lift the harvest, and could transfer it by moving sidewise because this carrier was able to follow the Welsh onion harvester closely. Compared to a normal carrier without a following system, this carrier reduced the number of times and the distance the workers moved in the field.