TY  - JOUR
PY  - 2015//
TI  - Great cities look small
JO  - Journal of the Royal Society, Interface
A1  - Sim, Aaron
A1  - Yaliraki, Sophia N.
A1  - Barahona, Mauricio
A1  - Stumpf, Michael P. H.
SP  - 20150315
EP  - 20150315
VL  - 12
IS  - 109
N2  - Great cities connect people; failed cities isolate people. Despite the fundamental importance of physical, face-to-face social ties in the functioning of cities, these connectivity networks are not explicitly observed in their entirety. Attempts at estimating them often rely on unrealistic over-simplifications such as the assumption of spatial homogeneity. Here we propose a mathematical model of human interactions in terms of a local strategy of maximizing the number of beneficial connections attainable under the constraint of limited individual travelling-time budgets. By incorporating census and openly available online multi-modal transport data, we are able to characterize the connectivity of geometrically and topologically complex cities. Beyond providing a candidate measure of greatness, this model allows one to quantify and assess the impact of transport developments, population growth, and other infrastructure and demographic changes on a city. Supported by validations of gross domestic product and human immunodeficiency virus infection rates across US metropolitan areas, we illustrate the effect of changes in local and city-wide connectivities by considering the economic impact of two contemporary inter- and intra-city transport developments in the UK: High Speed 2 and London Crossrail. This derivation of the model suggests that the scaling of different urban indicators with population size has an explicitly mechanistic origin.<p />  <p>Language: en</p>
LA  - en
SN  - 1742-5689
UR  - http://dx.doi.org/10.1098/rsif.2015.0315
ID  - ref1
ER  -