A traffic information providing system externally acquires traffic
information including information relating to the travel time of a link,
calculates a travel time for a non-provision link to which no travel time
is provided through estimate/complement operation. The
estimate/complement operation is carried out with use of travel times,
emergencies, travel times of links in the vicinity of the non-provision
link, and so on, obtained in the near past. The system stores and
statistically processes the externally-acquired traffic information, and
also estimates a travel time in the near future. When there is an
abnormality in the acquired traffic information, the system deletes the
abnormality, regards the information as a non-provision link, calculates
a probability distribution of travel times of links, calculates a
probability distribution of travel times of the entire route made up of a
plurality of links, and also calculates a probability for a specific
travel time range.