Gangtok 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 Gangtok plotted against Sikkim and India. The SNDi of new construction in Gangtok followed a zig-zag trend with an overall decrease, compared to Sikkim which was at its lowest in 1976-1990 and India which followed a zig-zag trend with an overall increase. Most recently, Gangtok's incremental SNDi fell from 11.43 to 11.3 between 1991-2005 and 2006-2020. In terms of the aggregate network, Gangtok ranked 1st out of 1 cities in Sikkim and 1854th 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?

• Vallejo, United States
• Battagram, Pakistan
• Kishi, Nigeria
• Laoling, China
• Pilsen, Czechia
• Kolpino, Russia

In new street additions, Gangtok fluctuated in its street-construction patterns, while Vallejo built increasingly disconnected streets from 1975 through 1976-1990, then improved and Laoling fluctuated in its street-construction patterns. Looking at the full network, Vallejo and Laoling both became progressively more disconnected, while Gangtok became more connected from 1975 through 1976-1990, then grew more sprawly from 1976-1990 onwards.