A method comprising: collecting a plurality of probe data from a plurality of probe points by a probing device, said probe data comprising at least positional information, a speed vector and a direction of travel of the probing device and a timestamp of recording the probe data at a probe point; and estimating a trajectory of the probing device between two consecutive probe points as a cubic Hermite spline having the positions of said two consecutive probe points as control points and the speed vectors of said two consecutive probe points as control vectors.