Alangulam 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 Alangulam plotted against Tamil Nadu and India. The SNDi of new construction in Alangulam rose steadily, compared to Tamil Nadu which rose steadily and India which followed a zig-zag trend with an overall increase. Most recently, Alangulam's incremental SNDi rose from 3.91 to 6.41 between 1991-2005 and 2006-2020. In terms of the aggregate network, Alangulam ranked 35th out of 121 cities in Tamil Nadu and 685th out of 1868 in India as of 2020.

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

What about similarly populated cities?

• Liu'erbao, China
• Quwo, China
• San Lorenzo, Argentina
• Móng Cái, Vietnam
• Dengkou, China
• Dhamdaha, India

In new street additions, Alangulam built increasingly disconnected streets over time, while Liu'erbao built increasingly connected streets from 1975 through 1976-1990, then shifted to more disconnected patterns and Móng Cái built increasingly connected streets from 1975 through 1991-2005, then shifted to more disconnected patterns. For the full network, Alangulam became progressively more disconnected, while Liu'erbao became progressively more connected and Móng Cái became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards. Notably, Alangulam had a more connected network than Liu'erbao in 1975 but the two have since reversed their relative ranking.