A topic guide explains one subject across cities — what the technology actually is, what the documented record supports, and the questions to ask before buying it. For the complete computed sets — every failure, every evidence grade, every operator — see the track record; for a reading order through hand-picked entries, take a curated tour.

Getting around

How people and vehicles move — the biggest slice of the atlas, from adaptive signals to driverless metros.

Water, energy and waste

The networked utilities: what a city pumps, powers, lights and collects.

Climate, health and the street

Where cities measure their environment — and what a reading is allowed to trigger.

The data layer

The plumbing behind everything else: sensor networks, registers and models — and the districts where cities test the whole stack at once.

Government, participation and watching

Digital government, who takes part in it — and who is allowed to check the cameras.

The six categories

A topic is a thread that runs across the atlas, and a project can carry several. A category is the one domain each project belongs to, so these six cover the corpus exactly once.