France

What the record shows

The most distinctive instrument in the French record is not a sensor — it is the recount. When Montpellier made its trams and buses free, the Métropole reported ridership up by more than a third after the first full year; the Cour des comptes put the net rise at about 20% and recorded fare revenue falling from roughly a third of operating costs to 6%. Part of why two numbers can coexist: abolishing ticket validation abolished the ridership meter, so the operator now counts passengers with cells fitted in every tram and bus. The same court, auditing Nice's camera estate — 2,232 public-road cameras, the largest in its 58-commune sample — found "no overall correlation between the existence of video-protection systems and the level of crime committed in public places, or clearance rates". In France the operator's number is where the story starts, not where it ends.

The courts then drew the line between filming and computing. From 2020 an algorithm watched the cameras at 144 school entrances in Nice and raised an alert whenever a vehicle parked longer than five minutes — until the CNIL held the treatment unauthorised, and on 30 January 2026 the Conseil d'État confirmed that the law permitting street cameras "cannot, in its silence, be interpreted as authorising algorithmic treatments allowing systematic and automated analysis of the images collected". The ruling binds every French municipality, and the atlas keeps the entry as it is: suspended, and graded a failure.

Who holds the contract is the other running question, because France operates much of its urban machinery through delegates. Autolib', the Bolloré Group's electric car-share, could not make the economics close: Bolloré tallied a ~€293.6M accumulated deficit and demanded the public syndicate absorb most of it; the syndicate refused, cancelled the contract, and the service shut down on 31 July 2018 — killed by a balance sheet rather than a court. Vélib', launched by JCDecaux in 2007, barely survived its own handover: when operations passed to the Smovengo consortium in January 2018, only 64 of a planned ~1,460 stations worked by that March. The counter-current is the régie: Montpellier took its drinking water back in-house in 2016 after 25 years of delegation to Veolia, and now fits remote-read meters — while not yet publishing, three years in, how many actually transmit; Eau de Paris, the public utility, reports network efficiency near 91%, among the highest in France.

Water is where French instrumentation is oldest — and where cities deliberately keep a person between the reading and the consequence. Nice began gauging its coastal streams in 1983; Bordeaux's RAMSES centre has regulated the sewer network in real time since 1992, and the sharpest line in its file is a 2014 study arguing that hydraulic models miss the commonest floods — blockages, roots, grease — which live in the maintenance backlog, not the control room. Montpellier's Ville en Alerte is explicit that nothing is actuated automatically: a gauge crossing a threshold raises an SMS, and an agent goes to look at the river before mayors are told, because a karst catchment produces false rises. The newest water entry closes the loop the old ones hold open: the Seine bathing sites, reopened in 2025 after a roughly €1.4bn cleanup, open or close each day on the water-quality reading.

French open data runs on national rails, and the completeness is real: Nantes carried an open licence on every one of its 589 datasets, Nice on all 268, Bordeaux's DataHub on 549 of 562. Liveness, not licensing, is the French failure mode: Nantes's catalogue held 859 datasets in 2017 and 589 now — it shrank; Nice has created no new dataset since June 2023; and the national access point where transport authorities are obliged to publish shows Nantes's real-time feeds half-lit, the GTFS-RT feeds international journey planners actually consume dark since 4 July 2026, through 40 consecutive automated warnings. Paris opened its portal in January 2011, and since 2014 has put about 5% of its investment budget to an online resident vote — 142,938 voters and 121 funded projects in 2024 — with the entry's own caveat: a record turnout is still a small share of two million residents.

Some French instruments exist to answer a political question, and say so. Nantes suspended its 5G rollout in late 2020, put it to a citizen debate, and built a permanent electromagnetic-field observatory out of one commitment — more than 1.2 million readings published, a mean field strength of 0.91 V/m against legal limits of 37 to 61 V/m, and by design no reading that triggers anything. The Grand Paris low-emission zone compresses the whole national arc into one entry: phased in from July 2019 on Crit'Air stickers; generalised by the 2021 Climat et résilience law, which required such a zone before the end of 2024 in every metropolitan agglomeration above 150,000 inhabitants; then softened, with camera enforcement postponed into a sanction-free "pedagogical" period running to December 2026 and the national regime relaxed until only the Paris and Lyon agglomerations still sit under binding schedules; and finally rescued from a National Assembly vote to scrap the zones outright when the Conseil constitutionnel struck the suppression out of the 2026 simplification law — not on the merits, but as a legislative rider. The most French artifact may be Nantes's cycle-counting network, which publishes beside each day's counts the metropole's own estimate of whether each counter was broken — 7.5% of all loop-days flagged as probably faulty — and warns in the dataset itself which comparisons the numbers will not bear. If the entries below agree on one lesson, it is that trust is built exactly there: in the caveat published next to the number, and in the recount by an institution that does not run the system.

Sources beyond the atlas

Facts above that do not come from a linked entry rest on these:

• Légifrance — Loi n° 2021-1104 du 22 août 2021 (Climat et résilience), article 119 — the mandate: a low-emission zone is obligatory before 31 December 2024 in every metropolitan agglomeration above 150,000 inhabitants
• Ministère de la Transition écologique — Zones à faibles émissions (ZFE) — the relaxed two-tier regime: binding restriction schedules only where air-quality thresholds are still regularly breached (currently the Paris and Lyon agglomerations); the rest are "territoires de vigilance" with a single minimal restriction
• Conseil constitutionnel — Décision n° 2026-903 DC du 21 mai 2026 — censures the article of the simplification law that abolished the low-emission zones, as a legislative rider with no link to the original bill (art. 45 of the Constitution)