Why are smart cities announced bigger than they get built?
Announced far larger than built — 20 documented cases in this atlas, each linked to its sources.
The test: Is the gap between what was promised and what stands the main fact about it?
These are the projects the phrase "smart city" is usually arguing about, and they are a minority of the failures in this atlas — worth saying plainly, because they dominate the coverage. The Line went from a 170 km linear city to a 2.4 km first phase and then to suspended construction inside three years. Masdar was billed at launch as the world's first zero-carbon city and had its target downgraded to low-carbon by 2050. Delhi built two 24-metre air-purifying towers; its pollution control committee later told the National Green Tribunal that cutting the city's pollution 17% this way would take about 40,000 of them. The gap does not always open at the announcement — Barcelona built four of a planned one-in-three green streets before a new administration ruled out the rest, and Madrid's participatory budget halved after a change of mayor. And the gap need not be physical: Amsterdam promised sixty fully described algorithms in its public register by the end of 2023, and its own court of audit counted twenty-nine.
Two labels, kept apart. 2 of these are recorded as failed — stopped, cancelled, or demonstrably not doing what it was built to do — and 18 as scaled back, which mostly means a service that still runs but delivered materially less than promised. An entry earns either label only where a named source says so.
✔ Every published entry is checked against the public sources it cites before publication.
The 20 documented cases
The other five patterns
The whole record
Every entry in the atlas that failed or was scaled back, all six patterns in one place, with the arithmetic behind the share: smart city project failures.