Collaborator: Prof. D. Veneziano (CEE, MIT).
a. Distribution of population density in the Continental US at 1 km resolution. b. Results of multifractality test, the slope in log-log scale from the q moments of population density measured at different resolution n (symbols) compared with multifractal behavior (solid line). c. Detailed density of population of areas in which mobile phone data is available to perform a comparative study of trips.
The origin-destination matrix (OD), is a network of aggregated trips that allows one to test some ideas about the structure of human movement, there are many factors that control it: land use, location of industries and residential areas, accessibility, etc., and it seems difﬁcult to provide a general and simple enough model. Most of the studies are descriptive or empirical, i.e. they either present case studies or use regression analysis to quantify the inﬂuence on mobility characteristics of factors like neighborhood density, distance from the city center, measures of land use mix, street connectivity and socioeconomic factors. Fewer studies are theoretical, deriving mobility descriptors from assumed spatial distributions of trip origins and potential destinations and models for trip initiation and the choice of destination and transportation mode.
Impact: We will validate and calibrate multiplicative models by analyzing the spatial distribution of population (a surrogate for demand) inside metropolitan areas in different countries. We plan to make extensive analysis of population and supply data to support the models of S and D and its effect in trips. Using mobile phones we will compare trip length distributions and construct mobility networks and try to provide an uniﬁed framework to test OD models.