Zabol 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 Zabol plotted against Sistan and Baluchestan and Iran. The SNDi of new construction in Zabol was at its lowest in 1976-1990, compared to Sistan and Baluchestan which was at its lowest in 1991-2005 and Iran which rose steadily. Most recently, Zabol's incremental SNDi rose from 3.25 to 4.16 between 1991-2005 and 2006-2020. In terms of the aggregate network, Zabol ranked 7th out of 7 cities in Sistan and Baluchestan and 115th out of 169 in Iran as of 2020.

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

What about similarly populated cities?

• Kamrej, India
• Maicao, Colombia
• Epe, Nigeria
• Banjariya, Nepal
• Zhodzina, Belarus
• Sinchon, North Korea

In new street additions, Zabol and Banjariya both built increasingly connected streets from 1975 through 1976-1990, then shifted to more disconnected patterns, while Kamrej fluctuated in its street-construction patterns. For the full network, Zabol became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards, while Kamrej became progressively more disconnected and Banjariya became more connected from 1975 through 1976-1990, then grew more sprawly from 1976-1990 onwards. Zabol and Kamrej have been growing further apart in their street-network character since 1975.