Fig. 4
From: Transport indicator analysis and comparison of 151 urban areas, based on open source data
Multi variant diagram of small cities. Congestion level (ADETT) over Road IA; Bubble size is proportional to the population density; filled color indicates Train IA, bubble border color indicates Cycle IA, color of starred city- labels indicate BRT IA. For color scaling, see Table.5. The dotted line represents the fitted exponential curve from Eq.(1)