Gusau in context: Street-network sprawl trends

Gusau in context

2.12.83.54.2<19751976–19901991–20052006–2020SNDi of street additions
2.12.83.54.2<19751976–19901991–20052006–2020SNDi of entire street network
GusauZamfara (Region)Nigeria (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Gusau plotted against Zamfara and Nigeria. The SNDi of new construction in Gusau peaked in 1991-2005, compared to Zamfara which peaked in 1976-1990 and Nigeria which followed a zig-zag trend with an overall increase. Most recently, Gusau's incremental SNDi fell from 2.56 to 2.48 between 1991-2005 and 2006-2020. In terms of the aggregate network, Gusau ranked 4th out of 9 cities in Zamfara and 119th out of 422 in Nigeria as of 2020.

New Street Additions (2006–2020)

SNDi value
2.48
Rank in Nigeria
76th of 422
Rank in Zamfara
5th of 9

Entire Network (Aggregate)

SNDi value
2.43
Rank in Nigeria
119th of 422
Rank in Zamfara
4th of 9

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

What about similarly populated cities?

1.62.43.24<19751976–19901991–20052006–2020SNDi of street additions
1.62.43.24<19751976–19901991–20052006–2020SNDi of entire street network
GusauHeyuanPetrolina

In new street additions, Gusau built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Heyuan built increasingly connected streets from 1975 through 1976-1990, then shifted to more disconnected patterns and Petrolina fluctuated in its street-construction patterns. For the full network, Gusau and Petrolina both became progressively more disconnected, while Heyuan became progressively more connected. Gusau and Heyuan have been converging in their street-network character since 1975.