Comparison of population density distribution of empirical data and our model.

Panel (A) shows the Chicago land-use map. (B) displays the effective population density distribution from the Chicago OD survey data. Panels (C) and (D) shows the effective population density from our simulations with distance exponents σ = 1.5 and 2.5 respectively (the optimal value is in between—σ = 1.90±0.04). The resolution of the map (i.e. the dimensions of a grid cell) is 700m × 700m.