1001 Smart Cities
🇬🇧 London

London Adaptive Traffic Signals (FUSION / Real Time Optimiser)

🤖 AI-generated summary of the sources below · 🔎 Last verified · ◆ 8 sourced claims, none individually verified yet

This overview was generated with AI from the public sources listed below and checked against them before publication. It has not had a complete human fact-check — treat it as a starting point and follow the sources.

How this atlas is made · What “last verified” means · What “source-checked” means · The full record behind this page

Since 2020 TfL and Yunex Traffic (formerly Siemens Mobility, with the University of Southampton) have been developing FUSION, an adaptive signal-control system meant to replace the 30-year-old SCOOT by drawing on richer multi-modal data, including connected-vehicle and bus feeds. In June 2024 TfL completed migrating almost 4,000 junctions and 1,500 pedestrian crossings onto the cloud-based Real Time Optimiser platform that will host it — some 5,500 of the roughly 6,400 signal sites it manages. FUSION itself is still running at a handful of 'living laboratory' trial junctions while SCOOT keeps controlling most of the capital. TfL's 2026 'London on the move' strategy projects up to 14% less delay and ~£1bn in benefits once FUSION progressively replaces SCOOT; AI-based enhancements are framed as a future upgrade, not a current capability.

Live 📅 since 2020
Outcome🔄 Ongoing
Evidence🏛️ Officialgrades the sourcing — this entry states no impact figure
what does this mean?The strongest source is the operator's or the city's own reporting — an official report, dataset or press release. It grades who did the looking — not how well the project went. All four grades →
Run byTransport for London (Yunex Traffic vendor)
Scale🏙️ City-wide
🚲 MobilityTraffic managementSensors & IoTPublic transport

Sources

↗ TfL / Yunex Traffic press release, 'TfL and Yunex successfully complete world-leading upgrade to London's traffic signal system', 10 June 2024Confirms June 2024 completion of the cloud RTO migration: ~6,400 signal sites, ~4,000 junctions, 1,500 crossings, 16,000+ detectors; FUSION to replace SCOOT
↗ Yunex Traffic newsroom, 'Urban Traffic Control solution live across London', 7 June 2024Confirms UTC-UX/RTO hosted platform live citywide (~5,500 junctions+crossings); FUSION deployment 'over the coming years' — i.e. platform complete, FUSION rollout ongoing
↗ Traffic Technology Today, 'Siemens Mobility and TfL announce launch of the new SCOOT' (Sitraffic FUSION, developed with University of Southampton)Published 24 September 2020Confirms vendor (Siemens Mobility, now Yunex) + University of Southampton, FUSION entered operation Autumn 2020 at trial sites, uses connected-vehicle and bus data
↗ TfL newsroom, 'TfL unveils ambitious five-year plan... London on the move', 26 Jan 2026Source of the 'up to 14% less delay' and ~£1bn benefit projection; states FUSION 'can be upgraded in future to take advantage of artificial intelligence' — AI is a future phase; 3,500 figure = signals on bus routes, not total
Show your work What this page rests on and what it can’t tell you · all 8 claims with their sources · the forensic record

Evidence Passport · public beta 8 addressable claims, 4 source dossiers, one permanent baseline. The passport is unreviewed — an AI-assisted structural migration, not a human or expert endorsement. Every revision keeps a permanent copy under revision history.

Inspect the claims, one by one — verbatim text, sources and caveats for all 8

The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.

Claim 1 clm-5ba8a2c0087040d7 quantitative
Since 2020 TfL and Yunex Traffic (formerly Siemens Mobility, with the University of Southampton) have been developing FUSION
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Traffic Technology Today (24 September 2020) reports the launch: "Siemens Mobility Limited and Transport for London (TfL) have announced the launch of Sitraffic Fusion", and that it was "Developed by Siemens Mobility in collaboration with TfL and supported by the University of Southampton." The vendor is quoted there as "Wilke Reints, MD, Siemens Mobility ITS, UK" -- the same person is quoted in the entry's 2024 sources as "Wilke Reints, Yunex Traffic Managing Director", which is the corroboration for "(formerly Siemens Mobility)", though this session could not load the 2024 releases directly (see the claim below on the RTO migration).
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Traffic Technology Today, 'Siemens Mobility and TfL announce launch of the new SCOOT' (Sitraffic FUSION, developed with University of Southampton)
Claim 2 clm-22cd9e7c237b6f96 quantitative
an adaptive signal-control system meant to replace the 30-year-old SCOOT
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Neither wired-gov.net nor yunextraffic.com could be loaded directly in this session (see caveat), but the joint TfL/Yunex release they carry is mirrored verbatim elsewhere: TfL's own newsroom platform (tfl-newsroom.prgloo.com, 7 June 2024) states SCOOT "has been operating across London for more than 30 years", and describes the system it replaces as having been "keeping London moving for more than 30 years"; a second, independent trade-press mirror of the Yunex release (highways.today, 8 June 2024) says FUSION "will replace the SCOOT system that has been operating across London for more than 30 years." "Adaptive signal-control system" matches how FUSION is described from its 2020 launch onward (Traffic Technology Today: "an all-new adaptive traffic control solution").
Caveat
Neither of the two listed URLs for this figure could be loaded in this verification session (wired-gov.net returned HTTP 503 / connection reset on repeated attempts; yunextraffic.com redirected to a bot-check page). The wording is corroborated only via independent mirrors of the same press release, not via the exact cited pages.

Sources carrying this claim

  1. TfL / Yunex Traffic press release, 'TfL and Yunex successfully complete world-leading upgrade to London's traffic signal system', 10 June 2024
  2. Yunex Traffic newsroom, 'Urban Traffic Control solution live across London', 7 June 2024
Claim 3 clm-66e0e68587362ce7 descriptive
by drawing on richer multi-modal data, including connected-vehicle and bus feeds
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Traffic Technology Today (24 September 2020): "The new Fusion system uses richer data sources from a variety of transport modes, including data from connected vehicles and buses," and earlier in the same piece: FUSION uses "connected vehicle data to identify pedestrians, cyclists and public transport vehicles, as well as cars."
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Traffic Technology Today, 'Siemens Mobility and TfL announce launch of the new SCOOT' (Sitraffic FUSION, developed with University of Southampton)
Claim 4 clm-630c80e1eb2faeaa quantitative
In June 2024 TfL completed migrating almost 4,000 junctions and 1,500 pedestrian crossings onto the cloud-based Real Time Optimiser platform that will host it
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Both listed URLs were unreachable directly in this session (see caveat), but the joint TfL/Yunex release they carry is mirrored on TfL's own newsroom (tfl-newsroom.prgloo.com, 7 June 2024), which confirms a June 2024 completion of the migration onto the cloud-based Real Time Optimiser (RTO) platform and that RTO "provides TfL with the platform to support the introduction of FUSION." The completion date and platform name are well supported; the '~6,400 / all' figure for what was migrated is not (see caveat).
Caveat
TfL and Yunex's own figures for the June 2024 migration are lower than 'all ~6,400': the mirrored release states "Almost 4,000 junctions, 1,500 pedestrian crossings, and more than 16,000 traffic detectors ... were seamlessly migrated" (roughly 5,500 junctions and crossings combined), and an independent trade-press mirror (highways.today, 8 June 2024) likewise gives "approximately 5,500 junctions and pedestrian crossing sites", "over 15,000 SCOOT® links" and "over 16,000 SCOOT® Detectors." The same TfL release separately says TfL manages "around 6,400 automated traffic signal junctions and pedestrian crossings" across London in total -- that is the figure for TfL's whole signal estate, not a stated count of what moved onto RTO in June 2024. Neither of the two cited URLs (wired-gov.net, yunextraffic.com) could be loaded directly in this session to confirm their exact wording first-hand.

Sources carrying this claim

  1. TfL / Yunex Traffic press release, 'TfL and Yunex successfully complete world-leading upgrade to London's traffic signal system', 10 June 2024
  2. Yunex Traffic newsroom, 'Urban Traffic Control solution live across London', 7 June 2024
Claim 5 clm-fbd7c0132591e879 descriptive
FUSION itself is still running at a handful of 'living laboratory' trial junctions
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Traffic Technology Today (24 September 2020) quotes Siemens Mobility's UK ITS Managing Director describing FUSION's initial deployment: it "will control a number of ‘living laboratory’ trial sites in London," used to "test increasingly complex functionality and verify its enhanced performance at existing traffic intersections in a live environment."
Caveat
The 2020 launch announcement says FUSION would run at 'a number of' trial sites, not a specific count, and none of the entry's four sources give a current (2026) figure for how many junctions FUSION runs at; 'a handful' is an editorial estimate rather than a cited number, and 'living laboratory' is a quote from the original 2020 launch rather than from a source describing FUSION's present-day footprint.

Sources carrying this claim

  1. Traffic Technology Today, 'Siemens Mobility and TfL announce launch of the new SCOOT' (Sitraffic FUSION, developed with University of Southampton)
Claim 6 clm-01764ff84cf8e792 descriptive
while SCOOT keeps controlling most of the capital
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The same 2020 article: "While SCOOT will continue to operate for the time being across most of the capital, Fusion will soon be tested, live, in specific areas."
Caveat
This description dates to September 2020, at FUSION's launch. None of the entry's other sources restate that SCOOT still controls 'most of the capital' as of the entry's 2026-08-06 lastVerified date; the 2026 TfL strategy source treats a wider FUSION rollout as still to come, which is consistent with, but does not independently confirm, SCOOT still being dominant today.

Sources carrying this claim

  1. Traffic Technology Today, 'Siemens Mobility and TfL announce launch of the new SCOOT' (Sitraffic FUSION, developed with University of Southampton)
Claim 7 clm-fa48d0d66267f607 quantitative
TfL's 2026 'London on the move' strategy projects up to 14% less delay and ~£1bn in benefits once FUSION progressively replaces SCOOT
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
TfL's 'London on the move' release (26 January 2026) ties these figures directly to FUSION rather than the five-year plan generally: "Improvements to London's world-leading FUSION traffic control system ... The changes could reduce delays by up to 14 per cent and deliver £1 billion in benefits through reduced journey times."
Caveat
The source does not use the phrase 'once FUSION progressively replaces SCOOT'; it frames the 14%/£1bn figures as flowing from 'improvements' to FUSION (updating it to analyse a broader range of data), without spelling out a specific SCOOT-replacement timeline or milestone tied to those numbers.

Sources carrying this claim

  1. TfL newsroom, 'TfL unveils ambitious five-year plan... London on the move', 26 Jan 2026
Claim 8 clm-4c0e0c533d56c756 descriptive
AI-based enhancements are framed as a future upgrade, not a current capability
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
TfL's release states FUSION "can be upgraded in future to take advantage of artificial intelligence sensors," explicitly placing AI in a future phase rather than describing it as already in use.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. TfL newsroom, 'TfL unveils ambitious five-year plan... London on the move', 26 Jan 2026
Forensic record — source dossiers, gaps, hashes and the exact revision this page renders

This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.

unreviewed Revision 2026-08-22-evidence-baseline effective 2026-08-06 · created 2026-08-22

Awaiting operator and domain-expert review; publication of this revision implies neither.

sha256:8aee675f5d3dcc292cdc846e8eefda4c7b4bd06f432e5cbfae435ed07867cc42
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
8
of 8 claims mapped
4
source dossiers
4
publication dates recorded
0
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
Transport for London (Yunex Traffic vendor)
Actor types
utility, private
Funding model
public
Funding description
Not recorded
Cost
Not recorded
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

4 source dossiers

TfL / Yunex Traffic press release, 'TfL and Yunex successfully complete world-leading upgrade to London's traffic signal system', 10 June 2024 wired-gov.net · 2 linked claims

Open original source ↗

Stable source ID
src-8b9d709534927e8c
Publisher
Name not classified · wired-gov.net
Type / language
web-page · language not classified
Published
2024-06-10
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-06
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Confirms June 2024 completion of the cloud RTO migration: ~6,400 signal sites, ~4,000 junctions, 1,500 crossings, 16,000+ detectors; FUSION to replace SCOOT

Descriptive only — not page/paragraph exact
Claims linked
Yunex Traffic newsroom, 'Urban Traffic Control solution live across London', 7 June 2024 yunextraffic.com · 2 linked claims

Open original source ↗

Stable source ID
src-7049d0840610bd57
Publisher
Name not classified · yunextraffic.com
Type / language
web-page · language not classified
Published
2024-06-07
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-06
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Confirms UTC-UX/RTO hosted platform live citywide (~5,500 junctions+crossings); FUSION deployment 'over the coming years' — i.e. platform complete, FUSION rollout ongoing

Descriptive only — not page/paragraph exact
Claims linked
Traffic Technology Today, 'Siemens Mobility and TfL announce launch of the new SCOOT' (Sitraffic FUSION, developed with University of Southampton) traffictechnologytoday.com · 4 linked claims

Open original source ↗

Stable source ID
src-4e0c171abfb7e6de
Publisher
Name not classified · traffictechnologytoday.com
Type / language
web-page · language not classified
Published
2020-09-24
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-06
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Confirms vendor (Siemens Mobility, now Yunex) + University of Southampton, FUSION entered operation Autumn 2020 at trial sites, uses connected-vehicle and bus data

Descriptive only — not page/paragraph exact
Claims linked
TfL newsroom, 'TfL unveils ambitious five-year plan... London on the move', 26 Jan 2026 tfl-newsroom.prgloo.com · 2 linked claims

Open original source ↗

Stable source ID
src-620ccd907f4f74aa
Publisher
Name not classified · tfl-newsroom.prgloo.com
Type / language
web-page · language not classified
Published
2026-01-26
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-06
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Source of the 'up to 14% less delay' and ~£1bn benefit projection; states FUSION 'can be upgraded in future to take advantage of artificial intelligence' — AI is a future phase; 3,500 figure = signals on bus routes, not total

Descriptive only — not page/paragraph exact
Claims linked
Known limits of this passport
  • Publisher names and source languages have not yet been classified; domains are recorded without guessing.
  • Existing source notes are descriptive locators, not page- or paragraph-exact citations.
  • A missing archive, publication date or content hash is shown as null rather than inferred.
  • The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim.

Continue exploring

Compare this project

🇬🇧 Vivacity AI Traffic-Sensor Network · London Vivacity's edge-AI sensors anonymously count road users and are meant to feed FUSION, the optimiser now being trialled on London's signals. 🇦🇺 SCATS — Sydney Coordinated Adaptive Traffic System · Sydney London's FUSION (2020) replaces its 30-year-old SCOOT, much as Sydney's SCATS has centrally retimed signals in real time since 1975. 🇺🇸 ATSAC Citywide Adaptive Traffic Signals · Los Angeles Central adaptive signals: LA's ATSAC has synced signals since 1984; London's FUSION now retimes ~6,400 sites from the cloud (2020).

Explore the wider context

🚦 Asphalt or algorithms🚦 Traffic management guide🏙️ London city profile🚲 Mobility projects📖 Adaptive traffic signals📖 Automated speed enforcement (speed cameras)📖 Congestion pricing
📎 Cite this project

1001 Smart Cities (2026). “London Adaptive Traffic Signals (FUSION / Real Time Optimiser)” — London, United Kingdom. The Smart City Atlas. https://1001smartcities.org/projects/london-fusion-adaptive-signals/ (last verified 2026-08-06). Data: CC BY 4.0.

The underlying data is free to reuse with attribution — see the open data page.

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