Signalen: Open-Source Public-Space Reporting Platform
A classifier reads each complaint and routes it to a department. A year before it went live, the city's own audit office found that reports marked handled were not always actually resolved.
123 documented projects · Explore all 123 Artificial intelligence projects →
"AI in cities" is rarely one technology. In the documented record it is four distinct jobs: watching, sorting, forecasting and scheduling. Separating them matters, because they differ completely in maturity, in evidence quality and in how much trouble they can cause.
This guide covers more than 40 documented entries across more than 30 cities in over 20 countries. The oldest is not recent at all: Los Angeles has run algorithmic signal control since 1984. Cities have automated decisions for forty years. What changed is the label, the scope — and the number of cameras.
Four distinct jobs recur across the documented record:
| Job | Examples | State of the evidence |
|---|---|---|
| Watching — cameras that classify what they see | Ho Chi Minh City, Kuala Lumpur, Warsaw | Outputs counted (violations, detections); outcomes rarely tested |
| Sorting — routing citizen reports and requests | Amsterdam, Buenos Aires | Measurable, modest, and the least contested |
| Forecasting — floods, leaks, load | Chennai, Barcelona, Beijing | Promising; almost all figures operator-reported |
| Scheduling — signals, heat, terminals | Pittsburgh, Copenhagen, Tianjin | The clearest efficiency gains, on narrow scopes |
Of the AI-tagged entries in the atlas that carry an evidence grade, the overwhelming majority are graded official — the operator's or the city's own account. Exactly one is peer-reviewed. That is the single most important fact on this page, and it is not an accusation: vendors and agencies publish what they measure, and nobody has funded the independent evaluations.
It does mean the well-known numbers should be read with their source attached. Hangzhou's City Brain reports roughly 15% higher travel speeds and halved emergency-response times — Alibaba's figures, not independently audited. Tianjin's automated terminal reports 60% fewer staff and 17%+ less energy — the operator's and Huawei's. A State Grid pilot cut blackout repair time from six-to-ten hours to about three seconds — state media, self-reported. Every one of those entries says so on its own page.
The sorting layer — routing citizen reports — is the boring, working part. Amsterdam's Signalen is the most instructive AI deployment in the atlas precisely because it is unglamorous. It auto-categorises public-space reports at a macro F1-score of 0.88 — and anything the classifier is less than 40% confident about goes to a human. The design states its own error rate and builds the fallback into the workflow.
Buenos Aires' Boti makes the complementary point about channels rather than models: launched on WhatsApp in 2019 rather than as a municipal app, it went from ~600,000 monthly conversations in 2020 to over 26 million in a single quarter by 2022. Its documented lesson is that meeting residents in the app they already use beat building a better one.
On trust, not accuracy. The largest AI-adjacent failure in the atlas was never switched on. Sidewalk Toronto was cancelled before construction, and the independently documented reason was unresolved data-privacy governance, not technical feasibility. Technology-first urbanism without public trust is dead on arrival.
Kuala Lumpur's record shows the live version of the same problem. Officials report street crime down sharply and credit the camera-and-AI network — self-reported figures — while the rollout outran the country's data-protection safeguards, from which government bodies are exempt, leaving facial-recognition oversight contested. And Hangzhou's own recorded lesson is the blunt one: big gains are available when a single platform gets all the data, at a privacy price most democracies will not pay.
The counter-move exists and is also in the atlas. Amsterdam's algorithm register — launched with Helsinki in 2020, absorbed into the Dutch national register in 2025 — publishes which systems the administration runs, for what purpose, on what data. Sensor registers and privacy registers extend the same idea. Cities that deploy AI without one are asking for trust they have not offered a way to check.
The practical takeaway: the AI that works in cities today is narrow, scheduled and boring — routing reports, timing signals, predicting leaks and load. The ambitious versions fail on governance rather than mathematics. Buy the narrow one, publish what you run, and treat any unaudited percentage as a claim until somebody outside the contract checks it.
Four distinct jobs, not one technology: watching (cameras that classify what they see), sorting (routing citizen reports and requests), forecasting (floods, leaks and energy load) and scheduling (traffic signals, district heating, port terminals). The record is older than the label — Los Angeles has run algorithmic signal control since 1984. The clearest efficiency gains come from narrow scheduling systems; the most contested deployments are camera networks.
The headline numbers are real but rarely independent. Hangzhou's City Brain reports roughly 15% higher travel speeds and halved emergency-response times — Alibaba's figures, not independently audited. Pittsburgh's decentralised Surtrac signals cut travel times about 25% and idling over 40% in the original nine-intersection pilot — research-team figures, with around 50 intersections running the system today.
On governance and trust, not on mathematics. The largest AI-adjacent failure in the atlas, Sidewalk Toronto, was cancelled before construction — the independently documented reason was unresolved data-privacy governance, not technical feasibility. Kuala Lumpur shows the live version of the same problem: its camera-and-AI rollout outran the country's data-protection safeguards, from which government bodies are exempt, leaving facial-recognition oversight contested.
A public list of which automated systems a city administration runs, for what purpose and on what data. Amsterdam launched one with Helsinki in September 2020, among the first city-level registers of their kind; Amsterdam's standalone register merged into the Dutch national Algorithm Register in 2025, which now lists 81 Amsterdam algorithms. Sensor registers and privacy registers extend the same idea.
Each of these reports impressive figures, and in each case the figure describes the system's own activity rather than the thing the system was bought to change. That is not dishonesty — it is what an operator can measure about itself — but it is the first question to ask of any of them.
| Project | Since | Status | Outcome | Evidence | Run by | Cost | What the reported number is about |
|---|---|---|---|---|---|---|---|
| Off-Site Environmental Supervision & Precision Enforcement PlatformNanjing, 🇨🇳 | 2023 | Live | Ongoing | Official | City government | not public | The enforcement process. Fewer site visits, more online ones, a higher detection rate — all real operational facts that say nothing about whether emissions fell, as the entry itself notes. |
| 'Open Doors, Fix Congestion' — Chengdu traffic police's AI signal and drone campaignChengdu, 🇨🇳 | 2024 | Live | Ongoing | Official | City government | not public | Individual corridors, because that is how the police report it. A citywide figure would hide that some streets improved sharply and most were untouched. |
| Bengaluru Adaptive Traffic Control SystemBengaluru, 🇮🇳 | 2024 | Live | Ongoing | Media | City government | not public | Upgraded corridors only — and the counter-fact is in the same entry: citywide rush-hour speed fell over the same period. |
| Amman AI Traffic Camera NetworkAmman, 🇯🇴 | 2025 | Live | Ongoing | Official | Utility or public operator | not public | A two-week baseline the operator set itself, before any fines were issued. Three quarters of the cameras never fine anyone at all. |