Zanzibar City in context: Street-network sprawl trends

Zanzibar City in context

2.42.83.2<19751976–19901991–20052006–2020SNDi of street additions
2.42.83.2<19751976–19901991–20052006–2020SNDi of entire street network
Zanzibar CityMjini Magharibi (Region)Tanzania (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Zanzibar City plotted against Mjini Magharibi and Tanzania. The SNDi of new construction in Zanzibar City peaked in 1976-1990, compared to Mjini Magharibi which peaked in 1976-1990 and Tanzania which was at its lowest in 1976-1990. Most recently, Zanzibar City's incremental SNDi fell from 2.79 to 2.66 between 1991-2005 and 2006-2020. In terms of the aggregate network, Zanzibar City ranked 1st out of 1 cities in Mjini Magharibi and 26th out of 45 in Tanzania as of 2020.

New Street Additions (2006–2020)

SNDi value
2.66
Rank in Tanzania
26th of 45
Rank in Mjini Magharibi
1st of 1

Entire Network (Aggregate)

SNDi value
2.5
Rank in Tanzania
26th of 45
Rank in Mjini Magharibi
1st of 1

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

What about similarly populated cities?

1.522.53<19751976–19901991–20052006–2020SNDi of street additions
1.522.53<19751976–19901991–20052006–2020SNDi of entire street network
Zanzibar CityLvivCuliacan

While Lviv and Culiacán both built increasingly disconnected streets over time, Zanzibar City built increasingly disconnected streets from 1975 through 1976-1990, then improved in new street additions. For the full street network, though, all three cities follow the same trend. Zanzibar City and Culiacán have been converging in their street-network character since 1975.