Green Wave for Cyclists (Grøn Bølge)
Time the lights to 20 km/h and a cyclist goes from as many as six red-light stops to zero or one. The same signals cost buses on those streets 27 to 50 seconds.
Smart cycling infrastructure is the data layer a city wraps around the bicycle: counting riders, timing signals for them, registering bikes against theft and regulating shared fleets by data feed rather than by ban. The bicycle itself needs none of it — which is why this record is unusually honest about what the technology adds and what only asphalt can do.
This guide connects the plain-language green wave definition with 39 documented projects in 30 cities. Who pays for and owns bike-share is covered in the shared mobility guide and our ownership essay; this page stays on the infrastructure side — the counters, signals, registers and fences.
Four mechanisms recur across the documented record:
| City | Instrument | What the record shows |
|---|---|---|
| Copenhagen | Green wave, since 2007 | Cyclist speed rose ~15→20 km/h, red-light stops fell from up to six to 0–1 — buses lost 27–50 seconds |
| Paris | Open counter network | Hourly counts published daily; the growth case for new lanes is publicly checkable |
| London | AI vision sensors | 1,000+ cameras, ~97% verified accuracy, no facial recognition; feeds signal control |
| Bogotá | Mandatory bike register | 552,920 bikes registered — but that is 41% coverage, and the sanction is a warning |
| Beijing | Data mandates + geofences | 1.144 billion shared-bike trips reported for 2024 — operator data, no independent audit |
Sometimes — and the strongest evidence points away from the gadgets. The single peer-reviewed win in this corpus is Beijing's green-travel incentive scheme, where a 2024 quasi-experiment found participants' subway trips rose 33.5% and car trips fell 14.1% — but cycling rose just 4.2%, the smallest shift of any mode. Copenhagen's green-wave numbers come from the city's own evaluation, which published the bus cost alongside the cyclist gain. Vienna's Supergrätzl shows discipline before data exists: its evaluation runs to September 2026, and no outcome numbers are claimed yet.
The register tells the same story from the other side. Bogotá recovered about one in five reported-stolen bikes in early 2026 — but of the bicycles recovered between 2021 and early 2024, roughly three quarters had never been registered. A database closes the loop only for objects that are on it.
No entry in this record failed because the technology stopped working. Copenhagen's Bycyklen — GPS and a tablet on every handlebar — grew from 169,000 to 933,000 rides in one year, went bankrupt in 2022 when the subsidies were withdrawn, and was never replaced. Bike Santiago shrank from 14 comunas to 5; with no public subsidy, the operator left the city's densest district via an in-app message, with no public decision taken. São Paulo pays its operator in advertising space — the promised e-bikes never arrived. Cairo's scheme collapsed twice in its first year, while roughly two of fifteen planned kilometres of protected lane were built. In Bogotá, trips fell 23% year-on-year and 110 of about 300 stations were vandalised. The pattern across all five: funding, contracts and street space decide outcomes; sensors and apps only report them.
The practical takeaway: instrument the street before you gadget the bike. The counter, the signal plan and the data clause outlast any app — every failure in this record was one of money or street space, faithfully recorded by technology that could not prevent it.
A run of traffic signals timed so cyclists riding at a steady speed hit consecutive green lights (full definition). Copenhagen has timed key corridors to 20 km/h since 2007: a city evaluation found average cyclist speed rose from about 15 to 20 km/h and red-light stops fell from as many as six to zero or one — at a cost of 27–50 seconds of added delay for buses on the same streets.
Two instruments dominate the documented record: permanent counters and computer vision. Paris publishes hourly counts from a network of permanent Eco-Compteur sensors as open data, refreshed daily. London draws on over 1,000 edge-AI camera sensors that classify road users on-device and discard the video within milliseconds; Transport for London independently verified their accuracy at around 97%.
Only for bikes that are on them. Bogotá runs Colombia's only municipal register — 552,920 bicycles by April 2026, which the city itself puts at 41% of its bikes. About one in five reported-stolen bikes was recovered in early 2026, but of the bicycles recovered between 2021 and early 2024, roughly three quarters had never been registered.
It varies more than cities expect. New York, Chicago and Boston publish open trip datasets from their bike-share systems. Santiago and Bogotá get only a real-time availability feed that sits on the operator's platform and declares no licence. Beijing inverts the relationship: dockless operators must stream fleet, parking and trip data to a municipal platform as a condition of deploying at all.
Counting bicycles is the easy part, and every one of these does it well. The ladder runs from a number nobody acts on to a signal plan that hands the cyclist the green light.
| Project | Since | Status | Outcome | Evidence | Run by | Cost | What happens to the count |
|---|---|---|---|---|---|---|---|
| Plan Vélo Digital Infrastructure MeshParis, 🇫🇷 | 2021 | Live | Ongoing | Official | City government | not public | Published. Permanent counters feed hourly totals into the open data portal on a rolling window, so anyone can audit whether the new lanes moved anything. |
| Vivacity AI Traffic-Sensor NetworkLondon, 🇬🇧 | 2018 | Live | Ongoing | Official | City government, Private company | not public | Classified on the device and the video thrown away — a deliberate privacy design, and a count split across two dozen boroughs that each bought their own. |
| Traffic Pilot — City-Wide Signal PredictionFrankfurt am Main, 🇩🇪 | 2022 | Live | Ongoing | Official | City government | not public | Handed back as advice: the app reads live signal phases and tells the rider what speed catches the green wave. |
| Green Wave for Cyclists (Grøn Bølge)Copenhagen, 🇩🇰 | 2007 | Live | Succeeded | Official | City government | not public | Built into the signal plan itself. The lights are timed to the cyclist rather than the cyclist to the lights — and the buses on those streets wait for it. |