Smart waste management is the data layer a city wraps around rubbish: sensors that report how full a bin is, scales and chips that price what a household throws out, GPS on the trucks — and, at the extravagant end, pipes that remove the truck altogether. It is also the field where the gap between how confidently it is sold and how little of it has been audited is widest.
This guide reads 24 verified projects in 23 cities, from Barcelona's 1992 vacuum network to Maidstone's enforcement drones. It is the companion to Pipes or pennies, our essay on what actually cuts municipal waste. Definitions: pneumatic waste collection and pay-as-you-throw.
Five mechanisms recur, and they are not equally proven:
| City | Instrument | What the record shows |
|---|---|---|
| Prague | Fill sensors, 7,000+ containers | Largest deployment here; no trip, fuel or emissions figure published |
| Melbourne | ~450 solar compacting bins | CBD collections fell from ~93,000 to ~14,500 a month (local press citing council data) |
| Rodgau | Solar compacting bins, ≈€5,000 each | Hotspots went from 2–3 emptyings a week to about one per six weeks (operator-reported) |
| Seoul | Per-kilogram RFID charging | 25% average cut across eight sites in the 2012 ministry pilot |
| Bergen | Pneumatic pipes, since 2015 | 10,000+ properties connected; no verified emissions or truck-trip figure |
| New York | On-street containers, no sensors | Rat-sighting complaints down 20.6% — but the fall began before containerisation |
Two things, neither of them the vendor's headline. Telemetry demonstrably stops needless emptying runs: Rodgau went from emptying busy squares two or three times a week to about once every six weeks, and Melbourne's CBD collections fell by around 85%. Both are real, and both come from bins that compact as well as sense: the saving is as much the press as the sensor.
The second is uncomfortable. No city here has published an audited business case for fill sensing at scale. Prague's 7,000 containers and Rome's 68 AMA bins report the hardware installed and nothing about the saving. As Pipes or pennies sets out, the only rigorous field evidence is a Coimbra trial finding 32–47% fewer collections — four bins, one street, flagged preliminary by its own authors — against a Valencia study that found sensors economically unjustified under that city's schedule.
The strongest numbers belong instead to price and process. Seoul's per-kilogram charging cut food waste an average 25% across eight pilot sites in 2012 (range 3–40%). Buenos Aires registered its cartoneros instead of policing them: 87,175 tonnes through its green centres in 2018, per peer-reviewed work. Shanghai and Beijing make the sequence explicit — the law came first, the digital layer afterwards. Shanghai now reports 7,927 tonnes of recyclables a day, 1.96 times its pre-regulation level, and a peer-reviewed evaluation found 83.6% of household food waste separated at 99.5% purity.
Rarely because the hardware broke. Hammarby Sjöstad's pipes are owned by property associations, not the city, and absorb 100–120 blockages a year from mis-sorted items at 1,500–3,000 SEK each; residents have lobbied Stockholm to take them over. Bergen's capital cost, and even its pipe lifetime, are locally disputed. Melbourne learned that solar compactors in shaded CBD canyons lose charge and stop pressing. Los Angeles scores every block for cleanliness but let publication thin to a dataset a year. Beijing's face-scanning bins were district pilots; some compounds abandoned theirs, and a national rule since June 2025 forbids face recognition as the only way to open one. Jakarta is the sharpest case: it has weighed every truck since 2015, and in March 2026 a waste slope collapsed and killed seven. Measuring a flow does not reduce it.
The practical takeaway: the wins here come from changing who pays or what the truck does — a per-kilogram fee, a press inside the bin, a container the loader arm can lift — not from instrumenting the bin and hoping. Telemetry earns its place by cancelling pointless trips; it has just never been asked, in public, to show the receipt.
No city in this atlas has published an audited answer. Prague runs the genre's largest network — more than 7,000 sensor-equipped containers — and Rome fitted 68 sensor bins from 2024; neither has released a trip, fuel or cost figure. The only rigorous field evidence is a Coimbra trial that found 32–47% fewer collections on four bins on one street, flagged preliminary by its own authors, against a Valencia study that found sensors economically unjustified under that city's existing schedule.
Underground vacuum pipes that carry waste from street inlets to a central terminal instead of sending trucks (full definition). Barcelona has run one since 1992, Hammarby Sjöstad since 2000 and Bergen since 2015 — where more than 10,000 properties are connected, but no independently verified emissions or truck-trip figure exists, the capital cost is locally disputed and the pipes' working life is genuinely contested. Hammarby adds the maintenance reality: 100–120 blockages a year from mis-sorted items, at 1,500–3,000 SEK each.
It has the strongest measured result in this corpus. A 2012 Korean ministry pilot at eight sites measured an average 25% cut in food waste, ranging 3–40% across sites, before Seoul's RFID weight-based fee went citywide in 2013 (what pay-as-you-throw means). The mechanism is a bill, not a sensor — which is also its political cost: a visible charge invites illegal dumping and a fairness argument a quiet sensor bin never has to survive.
No, and in China they may no longer rely on it alone. Beijing's face-scanning bins were a district pilot — a Xicheng compound from 2019 — and a swipe card or a button always opened them too; some compounds later abandoned the hardware. Under national rules in force since June 2025, face recognition may not be the sole verification method and an alternative must be offered.