Purnia 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 Purnia plotted against Bihar and India. The SNDi of new construction in Purnia rose steadily, compared to Bihar which followed a zig-zag trend with an overall increase and India which followed a zig-zag trend with an overall increase. Most recently, Purnia's incremental SNDi rose from 4.09 to 4.91 between 1991-2005 and 2006-2020. In terms of the aggregate network, Purnia ranked 67th out of 264 cities in Bihar and 1030th 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?

• Tongxiang, China
• Pabna, Bangladesh
• Dire Dawa, Ethiopia
• Ranghulu, China
• Wuzhou, China
• Chandrapur, India

In new street additions, Purnia built increasingly disconnected streets over time, while Tongxiang built increasingly disconnected streets from 1975 through 1991-2005, then improved and Ranghulu fluctuated in its street-construction patterns. For the full network, Purnia became progressively more disconnected, while Tongxiang grew more disconnected from 1975 through 1991-2005, then improved and Ranghulu fluctuated in connectivity. Purnia and Tongxiang have been converging in their street-network character since 1975.