1. A vehicle crash avoidance control apparatus comprising: an existence probability data generating section for calculating an existence probability in current and future space-time of a first vehicle from positional data associated with a position of the first vehicle and position error data to create existence probability data; an inter-vehicle communication section for transmitting said positional data and said existence probability data of the first vehicle and receiving positional data associated with a position of a second vehicle and said existence probability data; a collision probability calculating section for calculating the probability of the first vehicle colliding with the second vehicle and for calculating a spatiotemporal position at which a potential collision will occur based on said positional data and the existence probability data of the first and second vehicles; and an avoidance direction sending section for directing the first vehicle to avert a collision in accordance with said crash probability and said spatiotemporal position at which the collision will occur.