An apparatus for allocating a current measurement value for a geographical position to a map object of a geographical map, wherein the current measurement value originates from a series of adjacent measurement values for adjacent geographical positions, having a processor for determining a first probability measure indicating whether the current measurement value can be allocated to a first map object to which at least one adjacent measurement value of the series has already been allocated previously, and for determining a second probability measure indicating whether the current measurement value can be allocated to a second map object having an intersection with the first map object, if the first probability measure indicates that an allocation of the current measurement value to the first map object is unlikely.