A travel time data processing apparatus configured to process data regarding a travel time that is a time period required for traveling on a road, the travel time data processing apparatus comprising: a road network data storage configured to store road network data that includes link data representing roads; a probe information storage configured to store probe information obtained from each apparatus traveling on the road; and a travel time data calculator configured to use the probe information and calculate statistical data on the travel time with regard to each road corresponding to each piece of the link data; a travel time data processor that is configured to, when a time zone of statistical data of one piece of link data has an insufficient number of probe information for calculating the travel time of the road represented by the one piece of link data, select another piece of link data that satisfies a predetermined condition relative to the one piece of link data, select a time zone of statistical data of the another piece of link data that is identical with the time zone of statistical data of the one piece of link data, the travel time data processor characterized by being further configured to search the statistical data of the another piece of link data for another time zone that has similar statistical data to the statistical data of the selected time zone and further select this time zone of the another piece of link data, and add the number of probe information in a time zone of statistical data of the one piece of link data corresponding to this further selected time zone of the another piece of link data to the number of probe information in the time zone of the one piece of link data that has an insufficient number of probe information for calculating the travel time of the road represented by the one piece of link data. a road network data storage configured to store road network data that includes link data representing roads; a probe information storage configured to store probe information obtained from each apparatus traveling on the road; and a travel time data calculator configured to use the probe information and calculate statistical data on the travel time with regard to each road corresponding to each piece of the link data; a travel time data processor that is configured to, when a time zone of statistical data of one piece of link data has an insufficient number of probe information for calculating the travel time of the road represented by the one piece of link data, select another piece of link data that satisfies a predetermined condition relative to the one piece of link data, select a time zone of statistical data of the another piece of link data that is identical with the time zone of statistical data of the one piece of link data, the travel time data processor characterized by being further configured to search the statistical data of the another piece of link data for another time zone that has similar statistical data to the statistical data of the selected time zone and further select this time zone of the another piece of link data, and add the number of probe information in a time zone of statistical data of the one piece of link data corresponding to this further selected time zone of the another piece of link data to the number of probe information in the time zone of the one piece of link data that has an insufficient number of probe information for calculating the travel time of the road represented by the one piece of link data.