The invention relates to a method and apparatus for estimating a position of a vehicle, in particular an autonomously driven vehicle, by means of an apparatus for ascertaining a position of a vehicle. The invention proposes ascertaining a first absolute position by means of a conventional GNSS receiver. This should be compared with a second absolute position, which is ascertained in a protected safety unit or a protected ASIL-compatible chip, however, and is therefore always plausible.