Invariant statistical property throughout the road network evolution of Manila
We extract the road network information of the city of Manila, Philippines, for different periods, by georeferencing historical maps. The simplest metrical measures, the number and total lengths of nodes, show increasing trends, with a rapid increase between 1991 and 2019 for the number of roads. Topological measures, the number of nodes and edges, also show a sharp trend between these most recent data. On the other hand, the distribution of edge and road lengths show comparable behavior, with tails showing decreasing power-laws with an invariant scaling exponents 2.90. The results hint at complex and possibly mechanisms operating at the local scales in road network formation.