Colachel 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 Colachel plotted against Tamil Nadu and India. The SNDi of new construction in Colachel was at its lowest in 1976-1990, compared to Tamil Nadu which rose steadily and India which followed a zig-zag trend with an overall increase. Most recently, Colachel's incremental SNDi rose from 5.36 to 5.93 between 1991-2005 and 2006-2020. In terms of the aggregate network, Colachel ranked 106th out of 121 cities in Tamil Nadu and 1418th 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?

• Shahajadpur, Bangladesh
• Glasgow, United Kingdom
• Samarinda, Indonesia
• Ta'izz, Yemen
• Kananga, Democratic Republic of the Congo
• Honghuagang, China

While Shahajadpur and Ta'izz both fluctuated in its street-construction patterns, Colachel built increasingly connected streets from 1975 through 1976-1990, then shifted to more disconnected patterns in new street additions. For the full network, Colachel became more connected from 1975 through 1976-1990, then grew more sprawly from 1976-1990 onwards, while Shahajadpur fluctuated in connectivity and Ta'izz became progressively more disconnected. Colachel and Shahajadpur have been growing further apart in their street-network character since 1975.