1. A method of pre-processing probe data, the method comprising: examining a sequential dataset for a route of travel between two points; identifying at least one anomaly in the sequential dataset; and identifying at least a first and a second datum of the sequential dataset, wherein said first datum occupies a sequential position adjacent to the identified at least one anomaly; and. inserting at least one non-anomalous datum to occupy a sequential position of the identified at least one anomaly in the sequential dataset, the at least one non-anomalous datum being determined based on one of extrapolation, smoothing and interpolation of the at least first and second datum.