Igangan 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 Igangan plotted against Oyo and Nigeria. The SNDi of new construction in Igangan peaked in 1991-2005, compared to Oyo which followed a zig-zag trend with an overall increase and Nigeria which followed a zig-zag trend with an overall increase. Most recently, Igangan's incremental SNDi fell from 3.32 to 3.04 between 1991-2005 and 2006-2020. In terms of the aggregate network, Igangan ranked 8th out of 15 cities in Oyo and 150th 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?

• Chinnamanur, India
• Kashiwazaki, Japan
• Morales, Guatemala
• Qızıltöbe, Kazakhstan
• Bridgend, United Kingdom
• Sakti, India

In new street additions, Igangan built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Chinnamanur built increasingly disconnected streets over time and Qızıltöbe fluctuated in its street-construction patterns. For the full network, Igangan and Chinnamanur both became progressively more disconnected, while Qızıltöbe grew more disconnected from 1975 through 1991-2005, then improved. Igangan and Chinnamanur have been growing further apart in their street-network character since 1975.