A rear-road surface illumination apparatus is provided which includes: an avoidance determiner 30 to determine whether to provide a display to induce a following vehicle to avoid a vehicle, on the basis of vehicle information; and a controller 9 to cause an illumination light 10 to illuminate a rear road surface with light having illumination information that induces the following vehicle to avoid the vehicle when the avoidance determiner 30 determines to provide a display to induce the following vehicle to avoid the vehicle. Therefore, the rear-road surface illumination apparatus can indicate the existence of the vehicle to the following vehicle, to give the existence of the vehicle prominence, and can also make it easy to notify the driver of the following vehicle about what the driver of the vehicle desires the driver of the following vehicle to do.