On the key features in human mobility: Relevance, time and distance

Our era of increased people mobility requires a better understanding of how people move, how many are the places that a person commonly visits, how people move among them. In our previous work we have shown that the number of visited points of interest (PoIs) of each person is regulated by some laws that are statistically similar among individuals, and we gave some classification of them in terms of their relevance. We investigate here the variables that characterize the way humans move among PoIs, and in particular the spatial and temporal distances between PoIs and the PoIs relevance. With this respect, most of the existing work on mobility, especially on its modeling, is based only on spatial distance, while we argue here that for human mobility the temporal distance and the PoIs relevance are essential factors. Also, by comparing the geographical and temporal distances between consecutive PoIs, we observe a smoother and more linear trend in the temporal case. The results suggest that the time, rather than physical distance, could represent a better measure of distance among PoIs, mainly due to the transportation facilities. We present here our analysis of this aspect, considering two different datasets, to show the validity of our results independently of the nature of the dataset under consideration, and to extract considerations on different scenario scales. We argue that these results can be seminal to novel mobility research.