1. A branching and merging determination apparatus comprising: an image extraction unit having a processor that images an environment of an own vehicle and output an imaging result; a target object recognition unit having a processor that recognizes a target object present in front of an own vehicle, based on the imaging result, and outputs a recognition result; and a branching or merging road determination unit having a processor that determines, based on the recognition result, a presence or absence of branching or merging of roads, wherein the determination unit is configured to: estimate a traveling section where branching or merging of roads is probably present, and determine that no branching or merging of roads is present in a region in which there is a preceding vehicle traveling at a higher speed than the own vehicle, the region being a region of the estimated traveling section.