3D-model-based tracking offers one possibility to explicate the manner in which spatial coherence can be exploited for the analysis of image sequences. Two seemingly different approaches towards 3Dmodel-based tracking are compared using the same digitized video sequences of road traffic scenes. Both approaches rely on the evaluation of greyvalue discontinuities, one based on a hypothesized probability distribution function for step-discontinuities in the vicinity of model-segments, the other one based on extraction of Edge Elements (EEs) and their association to model-segments. The former approach could be considered to reflect a stronger spatial coherence assumption because the figureof-merit function to be optimized collects evidence from all greyvalue discontinuities within a tolerance region around visible model segments. The individual association of EEs to model-segments by the alternative approach is based on a distance function which combines differences in position and or...