PROBLEM TO BE SOLVED: To obtain a system to update, expand and/or improve a geographical data base. SOLUTION: Each of data collection sensors is installed on individual plural vehicles 50 and provides outputs showing one or more features of regions. A computer program executes the feedback processing of a geographical data base 20 by utilizing the outputs of the data collection sensors. The 1st part of this feedback program compares data specifying a physical feature with the output of the data collection sensor and the comparison result is presented. The 2nd part of this feedback program responds to the result resulting the 1st part and judges the significance of the comparison. The 3rd part of the feedback program corrects the data of the geographical data base 20 based on the significance judged by the 2nd part of the program.