To rapidly and reliably measure a road surface property using measurement results and determination results of a road surface in the past. A vehicle mounted with a road surface property acquiring device is guided to a specified point on a road and measurement is carried out. The past road surface data on a past road surface property is acquired, a present position of the vehicle is acquired, and a past road surface property image representing a feature amount of the road surface property in a range including the present position created based on the past road surface data is displayed; and the vehicle is guided from the present position to a specified area while measuring a state of the road surface with the road surface property acquiring device.
展开▼