An object detection apparatus comprising: an input port adapted to receives target information including pieces of information associated with respective objects of a plurality of objects in surroundings of a vehicle and to receive traffic information representing a traffic environment in surroundings of the vehicle, the target information of the plurality of objects being detected by a sensor installed on the vehicle; a memory adapted to store the received target information and the received traffic information; in a case where the total amount of data of the target information is greater than a determined value, a controller adapted to determine, based on the target information and the traffic information, priority for each of the plurality of objects, the controller adapted to select pieces of information from the target information based on the priority; and an output port adapted to output the selected pieces of information to an in-vehicle apparatus that controls the vehicle, wherein the total amount of data is an amount of data of the target information, wherein the determined value is a product of a data output rate at the output port and a predetermined time period for outputting the target information to the in-vehicle apparatus, wherein information on each object detected by the sensor includes a plurality of items associated with the object, wherein the output port is adapted to output, to the in-vehicle apparatus, pieces of information belonging to a first group and pieces of information belonging to a second group being lower in priority than the first group, and wherein the number of items included in the first group is larger than the number of items included in the second group. an input port adapted to receives target information including pieces of information associated with respective objects of a plurality of objects in surroundings of a vehicle and to receive traffic information representing a traffic environment in surroundings of the vehicle, the target information of the plurality of objects being detected by a sensor installed on the vehicle; a memory adapted to store the received target information and the received traffic information; in a case where the total amount of data of the target information is greater than a determined value, a controller adapted to determine, based on the target information and the traffic information, priority for each of the plurality of objects, the controller adapted to select pieces of information from the target information based on the priority; and an output port adapted to output the selected pieces of information to an in-vehicle apparatus that controls the vehicle, wherein the total amount of data is an amount of data of the target information, wherein the determined value is a product of a data output rate at the output port and a predetermined time period for outputting the target information to the in-vehicle apparatus, wherein information on each object detected by the sensor includes a plurality of items associated with the object, wherein the output port is adapted to output, to the in-vehicle apparatus, pieces of information belonging to a first group and pieces of information belonging to a second group being lower in priority than the first group, and wherein the number of items included in the first group is larger than the number of items included in the second group. a controller adapted to determine, based on the target information and the traffic information, priority for each of the plurality of objects, the controller adapted to select pieces of information from the target information based on the priority; and an output port adapted to output the selected pieces of information to an in-vehicle apparatus that controls the vehicle, wherein the total amount of data is an amount of data of the target information, wherein the determined value is a product of a data output rate at the output port and a predetermined time period for outputting the target information to the in-vehicle apparatus, wherein information on each object detected by the sensor includes a plurality of items associated with the object, wherein the output port is adapted to output, to the in-vehicle apparatus, pieces of information belonging to a first group and pieces of information belonging to a second group being lower in priority than the first group, and wherein the number of items included in the first group is larger than the number of items included in the second group.