Ilishan in context: Street-network sprawl trends

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Ilishan plotted against Ogun and Nigeria. The SNDi of new construction in Ilishan rose steadily, compared to Ogun which rose steadily and Nigeria which followed a zig-zag trend with an overall increase. Most recently, Ilishan's incremental SNDi rose from 3.58 to 4.56 between 1991-2005 and 2006-2020. In terms of the aggregate network, Ilishan ranked 5th out of 16 cities in Ogun and 192nd out of 422 in Nigeria as of 2020.

Rankings go from most connected to most disconnected — rank 1 is the most connected.

What about similarly populated cities?

• 龙山镇, China
• Tafawa-Balewa, Nigeria
• Rajauli, India
• Tubu, China
• Scranton, United States
• Mekoni, Ethiopia

In new street additions, Ilishan built increasingly disconnected streets over time, while 龙山镇 built increasingly connected streets from 1975 through 1991-2005, then shifted to more disconnected patterns and Tubu fluctuated in its street-construction patterns. For the full network, Ilishan and Tubu both became progressively more disconnected, while 龙山镇 became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards. Ilishan and 龙山镇 have been converging in their street-network character since 1975.