Gomi and Ide 1999 : The development of prototype autonomous transport vehicles for use on construction sites is described. Such vehicles are expected to be in high demand in the near future in countries where the aging of construction workers is becoming a serious problem. Two prototypes have been built so far and have undergone extensive testing. Vision systems used in the very rough operational environment of construction sites is discussed, as well as other aspects of the vehicle. A unique vision-based navigation operated well under extremely dynamic conditions. When completed in the near future, the project is expected to create a vehicle which would lessen the burden of workers on construction sites