Mexico City has been attaching legal force to measurements for longer than almost anywhere. Its air-monitoring network has run automatically since 1986, and a reading of 155 ppb of ozone still shuts building sites, caps a refinery and doubles the driving ban — the oldest such trigger in this atlas. The trouble is what the trigger reaches for. Hoy No Circula, in force since 1989, is the most-studied driving restriction anywhere, and three peer-reviewed evaluations have failed to find that it cleaned the air; households simply bought a second, older car. The city's clearest wins were bought with hardware rather than data: Metrobús cut commuters' pollutant exposure by replacing the buses, and Cablebús cut travel times by climbing hills.
The atlas documents 8 projects in Mexico City, the earliest dating to 1986: 1 with a documented success, 7 still running without a verdict. Every entry carries an evidence grade — the strongest here is peer-reviewed (5 entries) — and links its sources.
Three entries that show what Mexico City is actually doing.
Computed from the 8 entries below — a profile, not a score.
Instrumentation came first and it came early. Manual air sampling began in 1966, and in 1986 the automatic RAMA network started reporting ozone, carbon monoxide, sulphur dioxide and nitrogen oxides hourly from 25 stations. Hoy No Circula followed in November 1989 after an ozone emergency and became permanent the next year, with a compulsory emissions test twice a year deciding, via a hologram stuck to the windscreen, how hard the ban bites on each car. Two of the three layers the city still runs — a measurement, a legal consequence and a test that grades who is exempt — were in place before the phrase 'smart city' existed.
The 2000s bought the results the data layer never delivered. Metrobús opened on Avenida Insurgentes on 19 June 2005, and a peer-reviewed before-and-after study measured commuter exposure falling by up to 45 percent for carbon monoxide, 54 percent for benzene and 30 percent for fine particles — bought by swapping roughly 260 minibuses and 90 buses for about 98 articulated vehicles on one avenue. The GPS feed came thirteen years later. In 2009 the Ciudad Segura contract put 8,088 camera masts across the city, each carrying a loudspeaker, a strobe and a panic button wired to a district control desk; the same speakers now relay the national earthquake alert from about 13,900 poles.
From 2010 the city started building the softer layers. Ecobici opened that year and is now Latin America's largest bike share. Sectorisation of the water network began in 2019, cutting the distribution system into roughly 830 metered zones so leaks could be isolated — 484 were finished by August 2022, the 2024 completion target was missed, and a promised public dashboard of the readings never appeared. The Movilidad Integrada card arrived in October 2019 and swallowed the mode-specific cards; Cablebús lines opened in July and August 2021, climbing into the hillside neighbourhoods of Gustavo A. Madero and Iztapalapa.
Since 2024 the fare gate has opened and the evidence has hardened. The Metro withdrew the magnetic paper ticket it had sold since 1969 on 1 March 2024, and by 16 October that year an ordinary contactless bank card opened every turnstile in the network at the same five pesos — a fare unchanged since December 2013. Meanwhile the assessments arrived: ITDP and the Inter-American Development Bank measured Cablebús cutting travel times by almost 45 percent and running at 8.73 pesos per passenger, cheaper than the Metro or the buses; and Data Cívica and R3D found that about 60 percent of the city's crimes happen within 200 metres of a C5 camera while police use the footage in under 1 percent of investigations.
On a time axis, by the year each one started — 1986 to 2021. Pick a dot to read what it was.
✔ Every published entry is checked against the public sources it cites before publication.
Editorial links between Mexico City's own entries — the city as a system, not a list.
Plans and announced trajectories — not yet documented results.
Three questions are open, and each is about whether a measurement gets used. The C5 network is heading for roughly 119,000 cameras before the 2026 World Cup, and nothing about that expansion addresses the finding that prosecutors almost never pull the tape; a facial-recognition upgrade announced in 2019 has still never been independently confirmed as running, while officials say the cameras store no biometric data. The water utility was reconstituted as Segiagua in December 2025 with a budget up 26.7 percent and a plan to triple leak repairs and survey 800 kilometres of buried pipe by satellite and ground radar — against losses the utility itself puts at around 40 percent, and a promised measurements portal that is now four years overdue. And the oldest question stands unanswered: the ozone trigger has only ever been tightened, from 180 to 150 IMECA points in 2016, but the lever it pulls is a driving ban that the peer-reviewed record says does not work.
Where Mexico City appears in the atlas's own analysis.
Three cities the atlas reads next to Mexico City — the reason first, then the entries it rests on. Chosen by hand from the Mexico City threads below, not counted out of them.
The oldest plate rationing in the atlas and one of the least examined, side by side: Mexico City's has been evaluated repeatedly and found wanting, Manila's never at all — and both put money on a card that can quietly expire.
The densest pair in the atlas: cable cars up comparable hillsides, an electrified bus fleet against a bike-share, and two air thresholds that bind — Mexico City's by itself, Bogotá's only once a committee agrees.
Latin America's two long-running plate bans and its two largest camera estates: no study finds either ban made the air cleaner, and both cities own far more cameras than they ever open a case with.
Every editorial link from Mexico City's entries into another city, strongest first. Each one is a statement about two projects, not about two cities — the three above are the ones the atlas is willing to make at city level.
1001 Smart Cities (2026). “Smart-city projects in Mexico City, Mexico.” The Smart City Atlas. https://1001smartcities.org/cities/mexico-city/ (last verified 2026-08-27). Data: CC BY 4.0.
The underlying data is free to reuse with attribution — see the open data page.