A plurality of instances of probe data are received. Each instance of probe data corresponds to travel of a vehicle apparatus along a first segment, comprises an indication of at least one parameter characterizing the travel of the vehicle apparatus along the first segment. The at least one parameter is extracted from the instances of probe data to generate a distribution of parameters. One or more clusters of instances of probe data are identified based on the distribution of parameters. Responsive to identifying two or more clusters, a representative at least one parameter is determined for each cluster, and an element of a data structure is modified based thereon for each cluster. Responsive to identifying only one cluster of instances of probe data, the data structure is not modified based on the cluster. A navigation application is configured to use the data structure to perform a navigation function.