Fig. 1.

Reachable area in the dynamic traffic network from a typical site. Starting from a given site (e.g., Zhichun Road here) in Beijing (marked as a blue circle), the reachable area that one can access within a certain time (i.e., 15 min, 30 min, etc.) at a morning instance on (A) a holiday (October 1) and (B) a workday (October 15). (C) The size of the 30-min reachable area fraction (indicated by the number of reachable nodes divided by the total number of nodes in the road network) for a traveler from a given site in Beijing on the above holiday (squares) and workday (triangles). (D) Average path length at the boundary of the 30-min reachable area on the above holiday (squares) and workday (triangles). The results of (C and D) are averaged by 100 realizations (100 randomly chosen starting sites).