title: Understanding individual routing behaviour.
abstract: Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779-782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65-100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325-362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin-destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions.
authors.affiliation: Civil and Environmental Engineering Department, Massachusetts Institute of Technology, Cambridge, MA, USA antol@mit.edu.
authors.forename: Antonio
authors.identifier: http://orcid.org/0000-0002-4473-5311
authors.initials: A
authors.lastname: Lima
authors.affiliation: Telefonica Research, Barcelona, Spain.
authors.forename: Rade
authors.initials: R
authors.lastname: Stanojevic
authors.affiliation: Telefonica Research, Barcelona, Spain.
authors.forename: Dina
authors.initials: D
authors.lastname: Papagiannaki
authors.affiliation: Telefonica Research, Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodriguez
authors.affiliation: Civil and Environmental Engineering Department, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: Marta C
authors.initials: MC
authors.lastname: González
mesh_terms: D000203:Activities of Daily Living; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D014186:Transportation; D014505:Urban Population; D014506:Urban Renewal
keywords: city science; complex systems; human mobility; transportation