Vehicle speed calculator, and vehicle including same

A vehicle speed calculator comprising

• an image capturing unit attached to a vehicle, said image capturing unit captures an image of a road surface on which the vehicle is traveling;
• a traveled distance detection unit which detects a traveled distance per unit time of a feature point in a shooting range captured by the image capturing unit in a shot image;
• a vehicle speed calculation unit which calculates a vehicle speed of the vehicle relative to the road surface from the traveled distance detected by the traveled distance detection unit;
• a reference distance mark irradiation unit which irradiates, to the road surface, a reference distance mark formed in such a manner as to have a reference distance from the vehicle in a longitudinal direction of the vehicle in the shooting range in parallel with an optical axis of the image capturing unit;
• and
• an image reference distance detection unit which detects an image reference distance, which is the longitudinal length of the reference distance mark irradiated by the reference distance mark irradiation unit in the shot image;
• wherein the vehicle speed calculation unit calculates the vehicle speed from the traveled distance using the reference distance and the image reference distance detected by the image reference distance detection unit.