Patent ID: 7248947

Claim:
An information-sharing system, comprising an on-board information terminal provided on a vehicle, said on-board information terminal transmits at least one or more types of information among an on-board program information to acquire vehicle information relating to user's own vehicle and a shared information useful for driving of said vehicle; an area information acquiring system for acquiring an area information, which is an information on traffic condition on a driving road of said vehicle and in the surrounding of said driving road; and an information-sharing server for acquiring number of vehicles and for calculating time function existing quantity based on time function including said acquired existing quantity according to at least one or more types of information among said area information received from said area information acquiring system and said vehicle information received from said on-board information terminal, said information-sharing server further calculates time function transmission quantity to be transmitted to adjacent area as time elapses based on time function including said calculated time function existing quantity, arranges the calculated time function existing quantity and the time function transmission quantity at a corresponding position on a finely divided map, and when said on-board program information is received from said on-board information terminal, map information of said map where said time function existing quantity and said time function transmission quantity are arranged is attached to said on-board program information and is transmitted to said on-board information terminal.