Figure 2

The distribution of five motifs (dot colours) after twice convolutions, and selected 2 km-radius subareas with travel time performance (circles coloured by \({l}_{\tilde{t}}\)). Distributions of different motifs reflect the varied local PT system performances of subareas. The dot colour represents the accessibility of each node. The circle colour - for travel efficiency within a subarea - is different from the dot colour. The main figure demonstrates the whole distribution of motifs after convolutions. Each motif corresponds to a node’s function in its local context. In the legend “high” to “low” indicates its functional performance. Subfigures (A–E) are five sampled areas to demonstrate the association between motifs and the observed PT performance (designated by circle colour as different performance categories). The first three are typical patterns of each efficiency cluster whereas the rest two are unusual samples.