Tongxin 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 Tongxin plotted against Ningxia Hui and China. The SNDi of new construction in Tongxin peaked in 1991-2005, compared to Ningxia Hui which peaked in 1976-1990 and China which followed a zig-zag trend with an overall increase. Most recently, Tongxin's incremental SNDi fell from 5.42 to 4.69 between 1991-2005 and 2006-2020. In terms of the aggregate network, Tongxin ranked 14th out of 15 cities in Ningxia Hui and 1227th out of 1843 in China as of 2020.

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

What about similarly populated cities?

• Samitah, Saudi Arabia
• Pehowa, India
• Phúc Yên, Vietnam
• Rubio, Venezuela
• Bahma, Egypt
• Qaryat Salah al Din, Egypt

In new street additions, Tongxin built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Samitah built increasingly connected streets from 1975 through 1991-2005, then shifted to more disconnected patterns and Rubio built increasingly disconnected streets over time. For the full network, Tongxin and Rubio both became progressively more disconnected, while Samitah became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards. Notably, Tongxin had a more connected network than Samitah in 1975 but the two have since reversed their relative ranking.