Disclosed is a travel-time prediction apparatus that is capable of making a mid-term prediction of travel time accurately by combining present conditions and statistical information. The apparatus includes a travel-time transition pattern database storing travel-time transition patterns obtained by statistically processing past time-series data of each road link according to type of data. Upon accepting a travel-time transition pattern corresponding to a specified link and day type from the database, the apparatus calculates conversion parameters of a travel-time transition pattern for which an error between the travel-time transition pattern and a sequentially input travel-time time-series data will be reduced, and then makes a prediction using a prediction function obtained by converting the travel-time transition pattern by the calculated conversion parameters. The calculated predicted value and the conversion parameters are distributed as traffic information.