1001 Smart Cities

Permanent project revision

All-Biomethane City Bus Network

Revision 2026-08-28-tartu-baseline · effective 2026-08-28

Current revision. This is the snapshot used by the live entity page.

unreviewed

Created the first structured Evidence Passport with 17 claims and 10 source dossiers.

sha256:5d855b7672cf88c8e1438c82d4ee7f6d7c1503eb1f2a68420ecf6db8b16cc51c
All revisions → Current entity page →

Change set

  • add /evidencePassport — Added claim-level evidence mapping and source dossiers.
  • add /revisionHistory — Established a permanent, hash-addressed baseline revision.
17
of 17 claims mapped
10
source dossiers
8
publication dates recorded
0
archives linked
0
exact locators
0
content captures hashed

Claims, one by one

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-2742e45225894cf8 quantitative
From 1 July 2019 a single ten-year, €66 million contract handed Tartu's entire urban bus service to AS GoBus
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The contract release: 'the total value of the ten year contract is EUR 66 million. The contract will ensure convenient and environmentally friendly public transport for residents of Tartu from 2019-2029'. The first-year release: 'Go Bus has been operating Tartu city bus transport since 1 July 2019.'
Caveat
The contract was signed on 24 January 2018 — after Supreme Court judgements ended a challenge to the June 2017 award — and service began 1 July 2019 when AS Sebe's contract ran out.

Sources carrying this claim

  1. Tartu city government — contract signed with AS GoBus (authority)
  2. Tartu city government — first-year figures of the biogas buses (authority)
Claim 2 clm-08a7a57abe1e0232 quantitative
64 new gas buses
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The procurement terms: 'all of the 64 buses operating on city lines must be new and be fuelled by methane gas.'
Caveat
The tender required methane fuel, not specifically biomethane — the biomethane decision came separately with KIK support from 2020.

Sources carrying this claim

  1. Tartu city government — contract signed with AS GoBus (authority)
Claim 3 clm-5d98d3a04582249f descriptive
on a redesigned route network
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'As of 1 July 2019, the City of Tartu will be switching over to a new bus route network, which differs significantly from the current network in terms of itineraries, the number of lines, as well as the frequency of departures.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Tartu city government — new validators press release (authority)
Claim 4 clm-f925f729f3efb73e descriptive
validators taking contactless bank cards and QR tickets from day one
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'a new feature allows a contactless bank card to be used to purchase one-hour tickets' and 'As of 1 July, a new feature will allow people to use QR tickets.' The same release describes the automatic day-ticket cap after three one-hour tickets.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Tartu city government — new validators press release (authority)
Claim 5 clm-38bc516295295a56 quantitative
Since 1 January 2020 the fleet has run on Estonian-produced biomethane
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
City release: 'Alates selle aasta 1. jaanuarist sõidavad Tartu linnaliinide kõik 64 bussi taastuvkütusega - biometaani ehk rohegaasiga' (from 1 January of this year, all 64 city-line buses run on renewable fuel — biomethane). Alexela's chairman in the same release stresses it is produced in Estonia. KIK: from the start of 2020 the 64 buses run on biomethane.
Caveat
The most recent explicit confirmation found that the buses run on biogas is from March 2022 (the operator, in Postimees); the city's standing service pages since describe the fleet only as running on environmentally friendly fuel, while the network itself is documented operating into 2026.

Sources carrying this claim

  1. Tartu city government — city buses switch to green gas (authority, in Estonian)
  2. Environmental Investment Centre press release, via Elering's biomethane portal (authority)
Claim 6 clm-716b275d8de11df9 descriptive
dispensed by Alexela
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'Tartu city buses are supplied by biomethane energy company Alexela at the largest public gas station in the region at Ringtee 25 in Tartu.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. ERR News — Tartu buses start using biomethane (media)
Claim 7 clm-597053c817687632 descriptive
made from regional agricultural waste at the Ilmatsalu biogas plant
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The deputy mayor: 'the gas our buses use is produced from local agricultural waste at Ilmatsalu biogas plant'. The operator's Estonian version of the release adds that Ilmatsalu production started in the second half of 2020.
Caveat
In July–December 2019 the new buses ran on gas before the biomethane arrangement began; Ilmatsalu's own production started only in the second half of 2020, with Alexela supplying biomethane in the interim.

Sources carrying this claim

  1. Tartu city government — first-year figures of the biogas buses (authority)
Claim 8 clm-9fb57accbe40cabf quantitative
In 2020, the first biomethane year, ticket-sales data showed about 12 million passenger trips over 4.5 million bus-kilometres
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'According to ticket sales data, in 2020, the new biogas buses in Tartu operated by Go Bus travelled 4.5 million kilometers and made 12 million trips.'
Caveat
The release wavers between '12 million', 'exceeded 12 million' (operator quote) and, in the Estonian headline, 'nearly 12 million' — hence 'about'. It also sits above the 11 million registered in 2025; both are the city's/operator's validation-based figures, and the difference is unexplained.

Sources carrying this claim

  1. Tartu city government — first-year figures of the biogas buses (authority)
Claim 9 clm-b224d02f14e60516 quantitative
the 64 buses used 2 million kg of biomethane
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'Last year, the 64 buses used 2 million kg of biomethane or green gas.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Tartu city government — first-year figures of the biogas buses (authority)
Claim 10 clm-c87ff8d959a7dc6d quantitative
the operator estimated roughly 2,000 tonnes of CO2 kept out of the air compared with the old diesel fleet
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The Go Bus district manager: 'when compared to earlier, our buses emitted 2000 tons of less CO2.' The operator's Estonian version marks the figure 'hinnanguliselt' — as an estimate.
Caveat
The operator's own estimate, not an independent measurement. Keep it apart from KIK's ~11,000 t/yr projection (Tartu and Pärnu combined) and from the 4,330 t/yr later claimed on the Interreg good-practice page by the Association of Municipalities of Tartu County.

Sources carrying this claim

  1. Tartu city government — first-year figures of the biogas buses (authority)
Claim 11 clm-399f69d016810c16 quantitative
In 2025 the city registered 11 million trips
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'Möödunud aastal registreeriti Tartu linnaliinibussides kokku 11 miljonit sõitu' — last year a total of 11 million trips were registered on Tartu's city buses (release of 5 February 2026, so 'last year' is 2025).
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Tartu city government — low-use lines 25 and E1 end in March (authority, in Estonian)
Claim 12 clm-4ff21c4d915bbfc8 quantitative
per-line validation shares led it to cut two under-used lines from March 2026, at a stated saving of €200,000 a year
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The city ends lines 25 and E1 from 1 March because their usage is very low, citing each line's share of registered trips; 'Liinide sulgemisega on hinnanguline kokkuhoid 200 000 eurot aastas' — the closures save an estimated €200,000 a year.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Tartu city government — low-use lines 25 and E1 end in March (authority, in Estonian)
Claim 13 clm-73f3a7b71e9c073e descriptive
Validation is compulsory even for residents who ride free
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The service page on city-granted free travel: such passengers 'may travel for free, but must register every trip on the on-board validators'.
Caveat
Passengers whose free travel comes from the national Public Transport Act (rather than the city) are exempt from registering.

Sources carrying this claim

  1. Tartu city government — inner city bus transportation service page (authority)
Claim 14 clm-429992b2c205127f quantitative
it fed the analysis behind the 2019 route network
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The city's account of the network analysis: 'Bussikaardi valideerimisandmete põhjal hinnati reaalset bussiliinide kasutatavust' — actual line usage was assessed on the basis of bus-card validation data.
Caveat
An undated standing page; it describes the analysis that preceded the 1 July 2019 network.

Sources carrying this claim

  1. Tartu city government — bus traffic and network analysis page (authority, in Estonian)
Claim 15 clm-98c9b26d6e2c1693 quantitative
in 2026 it retired lines whose registrations made up 0.49 and 0.02 per cent of the year's trips
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
'Liini E1 registreerimised moodustasid sellest 0,02% ja liini nr 25 registreerimised 0,49%' — line E1's registrations made up 0.02% and line 25's 0.49% of the 11 million trips; both lines end 1 March 2026.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Tartu city government — low-use lines 25 and E1 end in March (authority, in Estonian)
Claim 16 clm-19b53901c32e7490 descriptive
biomethane's price is tied to the natural-gas market
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The article's opening: Estonian biogas is no cheaper than Russian natural gas, 'sest hind on seotud maagaasi turuhinnaga' — because its price is tied to the natural-gas market price; the support scheme pays the gap only while the market price stays under €100/MWh.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Postimees — Estonian biogas hits the wallet like Russian natural gas (media, in Estonian)
Claim 17 clm-503bdcf39a36fb34 quantitative
by 2022 the operator said the green gas had brought it no savings
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Go Bus's South Estonia regional manager Ramses Riive, March 2022: using biogas 'ei ole ... andnud kokkuhoidu ega leevendust' (has brought no savings or relief) — while confirming all the company's Tartu buses run on biogas and calling the green fuel important regardless of price.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Postimees — Estonian biogas hits the wallet like Russian natural gas (media, in Estonian)

Source dossiers and revision state

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 2026-08-28-tartu-baseline effective 2026-08-28 · created 2026-08-28

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

sha256:5d855b7672cf88c8e1438c82d4ee7f6d7c1503eb1f2a68420ecf6db8b16cc51c
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
17
of 17 claims mapped
10
source dossiers
8
publication dates recorded
0
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
AS GoBus (for Tartu city government)
Actor types
city-government, utility
Funding model
mixed
Funding description
City of Tartu service contract (≈€6.6M/year); EU Cohesion Fund via the Environmental Investment Centre for the biomethane price gap
Cost
€66M 10-year operating contract (2019–2029); ≈€7.7M biomethane switch, of which €2.23M EU Cohesion Fund
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

10 source dossiers

Tartu city government — contract signed with AS GoBus (authority) tartu.ee · 2 linked claims

Open original source ↗

Stable source ID
src-a113fd4b9bea2876
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
2018-01-26
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The city's own record of the 24 January 2018 signing: a ten-year contract worth EUR 66 million covering 2019–2029, requiring all 64 city-line buses to be new and fuelled by methane gas. It dates the procurement to the end of 2016, the award to AS GoBus (lowest tender, EUR 6.6 million a year) to June 2017, notes the signing waited for Supreme Court judgements over a challenge, and that the previous operator AS Sebe served until 30 June 2019.

Descriptive only — not page/paragraph exact
Claims linked
Tartu city government — new validators press release (authority) tartu.ee · 2 linked claims

Open original source ↗

Stable source ID
src-f8821382f98200ee
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
2019-06-18
Updated
2019-06-19
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Describes what changed on 1 July 2019: new validators on the new buses selling one-hour tickets to contactless bank cards, QR tickets, trip history at tartu.pilet.ee, and an automatic upgrade to a day ticket after three one-hour tickets in a day — alongside a new route network of 13 day lines and two night lines operated by AS GoBus.

Descriptive only — not page/paragraph exact
Claims linked
Environmental Investment Centre press release, via Elering's biomethane portal (authority) biometaan.info · 1 linked claim

Open original source ↗

Stable source ID
src-2708662aba9b6819
Publisher
Name not classified · biometaan.info
Type / language
web-page · language not classified
Published
2019-12-06
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

KIK's funding decision, in Estonian: from the start of 2020 Tartu's 64 buses run on biomethane; the EU Cohesion Fund contributes €2.23 million of the €7.66 million Tartu project, under a scheme that compensates the price difference between biomethane and fossil fuel. Also carries the deputy mayor's statement that since July 2019 only gas buses serve Tartu's public transport. Its ~11,000-tonne annual CO2 projection covers Tartu and Pärnu together and is not used in this entry.

Descriptive only — not page/paragraph exact
Claims linked
Tartu city government — city buses switch to green gas (authority, in Estonian) tartu.ee · 1 linked claim

Open original source ↗

Stable source ID
src-4a98d07fb2b0c5d1
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
2020-01-06
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The city's announcement that from 1 January 2020 all 64 city-line buses run on renewable fuel — biomethane — supplied by Alexela at the Ringtee 25 filling station, with production at Ilmatsalu planned for that summer, KIK support of about €2.2 million, and the city's own description of itself as one of the few medium-sized cities in Europe whose entire public transport runs on renewable fuel.

Descriptive only — not page/paragraph exact
Claims linked
ERR News — Tartu buses start using biomethane (media) news.err.ee · 1 linked claim

Open original source ↗

Stable source ID
src-9cba8359106cf72c
Publisher
Name not classified · news.err.ee
Type / language
web-page · language not classified
Published
2020-01-06
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Estonian public broadcasting's English-language report of the switch: buses powered by biomethane from the start of the year, supplied by Alexela at the region's largest public gas station at Ringtee 25, Ilmatsalu production to launch in the summer, and about €2.2 million of EU Cohesion Fund support through the Environmental Investment Centre.

Descriptive only — not page/paragraph exact
Claims linked
Tartu city government — first-year figures of the biogas buses (authority) tartu.ee · 5 linked claims

Open original source ↗

Stable source ID
src-830ed5bc715baa4c
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
2021-02-16
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The 2020 operating figures, from ticket sales data: 12 million trips and 4.5 million kilometres, 2 million kg of biomethane used by the 64 buses, and 2,000 tonnes of CO2 avoided — the operator's Estonian wording marks the CO2 figure as an estimate. Also states the gas is produced from local agricultural waste at the Ilmatsalu biogas plant and that Go Bus has operated the city lines since 1 July 2019.

Descriptive only — not page/paragraph exact
Claims linked
Postimees — Estonian biogas hits the wallet like Russian natural gas (media, in Estonian) majandus.postimees.ee · 2 linked claims

Open original source ↗

Stable source ID
src-718873a8ca3737de
Publisher
Name not classified · majandus.postimees.ee
Type / language
web-page · language not classified
Published
2022-03-27
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The business desk's examination of the price promise: biomethane's price is tied to the natural-gas market, production cost exceeds €2 per kilogram (about €100/MWh), and the state support that covers the gap stops when the market price is above €100/MWh. Go Bus's South Estonia regional manager says the biogas has brought the company no savings, and confirms all its Tartu buses run on it.

Descriptive only — not page/paragraph exact
Claims linked
Tartu city government — low-use lines 25 and E1 end in March (authority, in Estonian) tartu.ee · 3 linked claims

Open original source ↗

Stable source ID
src-fd9beda9b5ae6749
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
2026-02-05
Updated
2026-03-03
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The validation register in use: 11 million trips registered on city buses in 2025, line E1 accounting for 0.02% and line 25 for 0.49% of them (55,000 trips against 900,000 and 750,000 on the parallel lines), so both lines end on 1 March 2026 at an estimated saving of €200,000 a year. Only 4% of the airport's 43,693 Tartu–Helsinki passengers used the airport bus.

Descriptive only — not page/paragraph exact
Claims linked
Tartu city government — inner city bus transportation service page (authority) tartu.ee · 1 linked claim

Open original source ↗

Stable source ID
src-5d893649e46b328f
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The standing service page: 15 bus routes, the 64 Scania-built buses in two sizes, Ridango as the ticketing contact, the compulsory validation rule — including for passengers with city-granted free travel, who must still register every trip — and the bus card's use across Tallinn, several counties and Go Bus intercity lines.

Descriptive only — not page/paragraph exact
Claims linked
Tartu city government — bus traffic and network analysis page (authority, in Estonian) tartu.ee · 1 linked claim

Open original source ↗

Stable source ID
src-e44693b3458b4810
Publisher
Name not classified · tartu.ee
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-28
Dossier created
2026-08-28
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The city's public-transport hub page. Its account of the route-network analysis behind the redesign states that actual line usage was assessed from bus-card validation data, and that riders have access to real-time information on the web and on mobile; timetables link to the national peatus.ee journey planner.

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.