1001 Smart Cities

Permanent project revision

Hoy No Circula: Mexico City's Plate-Based Driving Restriction

Revision 2026-08-27-landmark-p6-uplift · effective 2026-08-27

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

unreviewed

Landmark-of-the-week editorial re-verification: full-field claim coverage (12 to 28 claims, every claim with a locator or an explicit reason), every source dated or explicitly null, six sources added (El Universal chronology and live rules pages, El Horizonte, the open Gallego working paper, the Guerra and Millard-Ball preprint), and three corrections — the 'Un Dia sin Auto' name belongs to a 1984 voluntary campaign rather than the 1989 decree, the five 2025 contingencies are re-anchored to a source that actually carries them, and Guerra and Millard-Ball's rejection of the second-car explanation is now presented as a contradiction in the record.

sha256:bc2c756c15b2edfcca5b6c2be6e16eeb1253facc880e865d59959eb5e36c8f8d
All revisions → Current entity page →

Change set

  • replace /snapshot/projectFingerprint — Updated projectFingerprint to the current sourced project record.
  • replace /snapshot/asOf — Updated asOf to the current sourced project record.
  • replace /snapshot/claims — Updated claims to the current sourced project record.
  • replace /snapshot/sources — Updated sources to the current sourced project record.
28
of 28 claims mapped
15
source dossiers
7
publication dates recorded
7
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-66cd2822e489894f quantitative
started keeping cars off the road one weekday a week by the last digit of their plate in November 1989, after an ozone emergency
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Davis (2017) carries the start and the motive in one sentence; Davis (2008) describes the plate-digit weekday mechanism; El Financiero dates the start to 20 November 1989 during an environmental emergency.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017
  2. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
  3. El Financiero — 'Hoy No Circula: origen, historia y por que se instauro este programa en la CDMX'
Claim 2 clm-4a03dd104b995183 descriptive
made the rule permanent the following year
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
El Universal's chronology, 1990 item: the programme was extended permanently, no longer only for the winter season.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 3 clm-c19d3297f5e262b6 descriptive
A compulsory emissions test every six months assigns each car a hologram
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
El Universal's verification page carries the semester rhythm — each sticker colour has two verification windows a year, and hologram 0 is listed with six-month validity ('vigencia semestral'); the chronology dates the verification programme itself to 1990.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. El Universal — vehicle verification rules page (continuously updated reference)
  2. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 4 clm-f07d03e622030cbc quantitative
holograms 00 and 0 drive every day, hologram 1 also rests two Saturdays a month, hologram 2 every Saturday
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
CAMe's description of the programme carries the hologram tiers and which of them rest on Saturdays; SEDEMA is the operator page for the same rules.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Comision Ambiental de la Megalopolis — 'El Programa Hoy No Circula que aplica en la Zona Metropolitana del Valle de Mexico'
  2. SEDEMA, Ciudad de Mexico — Programa Hoy No Circula
Claim 5 clm-f8ae7d9a3609a2c4 quantitative
Saturdays were added on 5 July 2008
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Davis (2017) dates the extension exactly; El Universal's chronology, written days before the launch, announces the same date.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017
  2. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 6 clm-a7148f006fd68da9 descriptive
when the metropolitan monitoring network pushes ozone past the contingency threshold the regional environment commission declares a 'Fase I' that pulls even exempt cars off the road
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The CAMe communique shows the commission declaring and maintaining a Fase I whose restrictions reach even normally exempt hologram 0 and 00 cars; El Horizonte reports the trigger reading (159 ppb of ozone) behind one such declaration.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Comision Ambiental de la Megalopolis — comunicado of 25 April 2026 maintaining the Fase I ozone contingency into the following Sunday
  2. El Horizonte — 'Activa CAME quinta contingencia ambiental por ozono en el ano' (25 April 2025)
Claim 7 clm-3918e7e8c63dfaa2 descriptive
Thirty-seven years on, peer-reviewed evaluations have still not found that the air got cleaner
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Davis (2008) found no evidence of improved air quality across pollutants and specifications; Davis (2017) found the Saturday extension had virtually no discernible effect. The 2017 behavioural study by Guerra and Millard-Ball reports no air-quality gain either.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
  2. Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017
Claim 8 clm-c05142d557d70a65 quantitative
Davis (Journal of Political Economy 116(1), 2008) found 'across pollutants and specifications there is no evidence that the restrictions have improved air quality', together with evidence that the ban raised the total number of vehicles in circulation and shifted the fleet toward high-emission cars.
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The abstract carries both halves verbatim: the null result across pollutants and specifications, and the evidence of more vehicles in circulation with a shift toward high-emissions vehicles.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
Claim 9 clm-0bae69017f650c62 quantitative
Davis (Scientific Reports 7:41652, 2017) found the July 2008 Saturday extension had virtually no discernible effect across eight pollutants, and no sign that drivers switched to metro, bus or light rail.
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The paper states both findings: virtually no discernible effect on pollution levels across eight major pollutants, and no evidence from subway, bus and light-rail ridership that drivers switched to lower-emitting transport.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017
Claim 10 clm-45ffb8fffa657de4 quantitative
Gallego, Montero and Salas (Journal of Public Economics 107, 2013) measured the workaround directly: an initial drop in car use followed by a rise in the household vehicle stock within eleven months.
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The published abstract carries the direction ('more cars on the road' and rapid household stock adjustment); the open working-paper abstract carries the figure verbatim: 'an expected short-run response followed by a rapid (before 11 months) increase in the stock of vehicles.'
Caveat
Guerra and Millard-Ball (2017) later rejected the finding that households adapt to the ban mainly through second-car purchases; the two measurements stand unreconciled in the literature.

Sources carrying this claim

  1. Gallego, Montero and Salas, 'The effect of transport policies on car use: Evidence from Latin American cities', Journal of Public Economics 107, 2013, pp. 47-62
  2. Gallego, Montero and Salas, 'The Effect of Transport Policies on Car Use: Theory and Evidence from Latin American Cities', Documentos de Trabajo 407, Instituto de Economia, PUC Chile (2011) — open working-paper version
Claim 11 clm-c02b4903279b2b8c quantitative
Guerra and Millard-Ball (Transportation Research Part D 55, 2017) confirmed the limited influence on driving but rejected the second-car explanation, finding most households instead shuffle trips to the days their car may drive.
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The preprint's abstract and highlights carry all three parts: 'Confirms findings that Hoy No Circula had a limited influence on driving', 'we reject the prevailing theory that its lack of success is due to perverse incentives for households to buy second cars', and 'Finds that households avoid ban by shuffling weekly travel routines.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Guerra and Millard-Ball, 'Getting around a license-plate ban' — author preprint, UCLA ITS (June 2017)
  2. Guerra and Millard-Ball, 'Getting around a license-plate ban: behavioral responses to Mexico City's driving restriction', Transportation Research Part D 55, 2017
Claim 12 clm-b6e0cd5194c879bb descriptive
Ration driving by plate digit and the trips find their way back — the studies disagree only on how: two measured households buying a second, usually older, car; the most recent finds most households simply shuffling trips to unrestricted days
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Davis (2008) found more vehicles in circulation and a shift toward high-emissions cars; Gallego, Montero and Salas measured the household stock rising within eleven months; Guerra and Millard-Ball reject the second-car theory and find day-shuffling instead.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
  2. Gallego, Montero and Salas, 'The effect of transport policies on car use: Evidence from Latin American cities', Journal of Public Economics 107, 2013, pp. 47-62
  3. Guerra and Millard-Ball, 'Getting around a license-plate ban' — author preprint, UCLA ITS (June 2017)
Claim 13 clm-9775dc12820fd6fd descriptive
One of the oldest and best-known schemes of its genre carries four peer-reviewed studies, and not one of them reports that it did what it was built to do
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Davis (2017) calls Mexico City 'home to one of the oldest and best-known driving restriction policies'. The four studies cited by this entry report a null air result, a fleet shifted older, a household stock rebound, and behavioural avoidance — none reports cleaner air.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017
  2. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
  3. Gallego, Montero and Salas, 'The effect of transport policies on car use: Evidence from Latin American cities', Journal of Public Economics 107, 2013, pp. 47-62
  4. Guerra and Millard-Ball, 'Getting around a license-plate ban: behavioral responses to Mexico City's driving restriction', Transportation Research Part D 55, 2017
Claim 14 clm-6154072a52ebdd2b quantitative
Mexico City started keeping cars off the road one weekday a week by the last digit of their plate in November 1989, after an ozone emergency, and made the rule permanent the following year
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Davis (2008) carries the plate-digit weekday mechanism; El Financiero dates the start to 20 November 1989 during an environmental emergency; El Universal's chronology carries the 1990 permanence.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
  2. El Financiero — 'Hoy No Circula: origen, historia y por que se instauro este programa en la CDMX'
  3. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 15 clm-a86267d740091154 quantitative
an ecologist group had launched a voluntary ‘Un Día sin Auto’, a day without the car, back in 1984
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
El Universal's chronology, 1984 item: the citizens' initiative 'Un día Sin Auto', promoted by the ecologist group 'Mejora tu Ciudad', proposing not to use the car one day a week.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 16 clm-5bc4e82d9aa17579 quantitative
it began on 20 November 1989 as a winter-season measure
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
El Financiero carries the exact start date during an environmental emergency; El Universal's chronology says the official 1989 programme applied to the winter season, when pollution levels are higher.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. El Financiero — 'Hoy No Circula: origen, historia y por que se instauro este programa en la CDMX'
  2. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 17 clm-da2d346b58597ddb quantitative
in 1990 it was made permanent, with the vehicle-verification programme established alongside it
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
El Universal's chronology, 1990 item, carries both: the programme extended permanently beyond the winter season, and the vehicle-verification programme established.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008)
Claim 18 clm-ee48b27635074471 quantitative
A compulsory emissions test every six months assigns each car a hologram, and that reading decides how hard the ban bites: holograms 00 and 0 drive every day, hologram 1 also rests two Saturdays a month, hologram 2 every Saturday
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
CAMe's description of the programme carries the hologram tiers and which of them rest on Saturdays; El Universal's verification page carries the six-month rhythm; SEDEMA is the operator page for the same rules.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Comision Ambiental de la Megalopolis — 'El Programa Hoy No Circula que aplica en la Zona Metropolitana del Valle de Mexico'
  2. El Universal — vehicle verification rules page (continuously updated reference)
  3. SEDEMA, Ciudad de Mexico — Programa Hoy No Circula
Claim 19 clm-b110d027832a161a descriptive
When the metropolitan monitoring network pushes ozone past the contingency threshold the regional environment commission declares a ‘Fase I’ that pulls even exempt cars off the road
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The CAMe communique shows the commission declaring and maintaining a Fase I whose restrictions reach even normally exempt hologram 0 and 00 cars; El Horizonte reports the trigger reading behind one such declaration.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Comision Ambiental de la Megalopolis — comunicado of 25 April 2026 maintaining the Fase I ozone contingency into the following Sunday
  2. El Horizonte — 'Activa CAME quinta contingencia ambiental por ozono en el ano' (25 April 2025)
Claim 20 clm-7930dd5c009face8 quantitative
CAMe activated five ozone Fase I contingencies in the first four months of 2025 alone
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
El Horizonte, reporting the 25 April 2025 activation: 'Esta es la quinta contingencia ambiental por ozono tras las del 26 de febrero, 18 de marzo, 1 de abril y 23 de abril' — the fifth ozone contingency of the year, after 26 February, 18 March, 1 April and 23 April.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. El Horizonte — 'Activa CAME quinta contingencia ambiental por ozono en el ano' (25 April 2025)
Claim 21 clm-a034516d71a831fc quantitative
the mechanism was still firing the following spring, holding a Fase I in place through a Sunday in April 2026
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The CAMe communique of 25 April 2026 maintains the Fase I ozone contingency and its measures 'para el día de mañana, domingo 26 de abril del 2026' — for the following day, Sunday 26 April 2026.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Comision Ambiental de la Megalopolis — comunicado of 25 April 2026 maintaining the Fase I ozone contingency into the following Sunday
Claim 22 clm-0b5f70ac48d9cee9 descriptive
‘across pollutants and specifications there is no evidence that the restrictions have improved air quality’
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Verbatim from the paper's abstract.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
Claim 23 clm-31c3f86ab4d2e7aa descriptive
evidence that the ban raised the total number of vehicles in circulation and shifted the fleet toward high-emission cars
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The abstract states: 'the restrictions led to an increase in the total number of vehicles in circulation as well as a change in composition toward high-emissions vehicles.'
Caveat
Guerra and Millard-Ball (2017) reject the finding that households adapt to the ban mainly by buying additional cars; the disagreement is presented later on this page.

Sources carrying this claim

  1. Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81
Claim 24 clm-26c8718fff3952dd descriptive
an initial drop in car use followed by a rise in the household vehicle stock within eleven months
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The open working-paper abstract carries the figure verbatim: 'an expected short-run response followed by a rapid (before 11 months) increase in the stock of vehicles.'
Caveat
Guerra and Millard-Ball (2017) later rejected the second-car explanation; the two measurements stand unreconciled in the literature.

Sources carrying this claim

  1. Gallego, Montero and Salas, 'The effect of transport policies on car use: Evidence from Latin American cities', Journal of Public Economics 107, 2013, pp. 47-62
  2. Gallego, Montero and Salas, 'The Effect of Transport Policies on Car Use: Theory and Evidence from Latin American Cities', Documentos de Trabajo 407, Instituto de Economia, PUC Chile (2011) — open working-paper version
Claim 25 clm-a2d6ea97cf37a835 quantitative
the July 2008 Saturday extension had virtually no discernible effect across eight pollutants, and no sign that drivers switched to metro, bus or light rail
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The paper: 'Across eight major pollutants, the program expansion had virtually no discernible effect on pollution levels', and it turns to 'evidence from subway, bus, and light rail ridership, finding no evidence that the expansion was successful in getting drivers to switch to lower-emitting forms of transportation.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017
Claim 26 clm-f2e2e8bea7a58e40 descriptive
reject the prevailing theory that its lack of success is due to perverse incentives for households to buy second cars
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Verbatim from the study's abstract, read in the authors' open preprint.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Guerra and Millard-Ball, 'Getting around a license-plate ban' — author preprint, UCLA ITS (June 2017)
  2. Guerra and Millard-Ball, 'Getting around a license-plate ban: behavioral responses to Mexico City's driving restriction', Transportation Research Part D 55, 2017
Claim 27 clm-2e5d5219cb84dd44 descriptive
avoid the ban by shuffling weekly travel routines
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
From the paper's highlights: 'Finds that households avoid ban by shuffling weekly travel routines.' The text adds: 'Shuffling travel days is less costly, more immediately available, and far simpler for most households than buying a second car.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Guerra and Millard-Ball, 'Getting around a license-plate ban' — author preprint, UCLA ITS (June 2017)
  2. Guerra and Millard-Ball, 'Getting around a license-plate ban: behavioral responses to Mexico City's driving restriction', Transportation Research Part D 55, 2017
Claim 28 clm-123a2c9c7699aada descriptive
Press reporting describes photo-enforcement cameras in Mexico City that sanction Hoy No Circula violations as well as speeding
Published field
body · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
adn40: 'Estos dispositivos no solo sancionan a quienes exceden la velocidad, también detectan conductores que circulan sin respetar las restricciones ambientales' — the devices sanction not only speeding but also detect drivers ignoring the environmental restrictions.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. adn40 — photo-enforcement cameras that sanction Hoy No Circula in CDMX (4 September 2025)

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 2026-08-27-landmark-p6-uplift effective 2026-08-27 · created 2026-08-27

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

sha256:bc2c756c15b2edfcca5b6c2be6e16eeb1253facc880e865d59959eb5e36c8f8d
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
28
of 28 claims mapped
15
source dossiers
7
publication dates recorded
7
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
Secretaria del Medio Ambiente de la Ciudad de Mexico (SEDEMA), with the Comision Ambiental de la Megalopolis (CAMe) coordinating the metropolitan zone and traffic police enforcing on the street
Actor types
city-government, regional-government
Funding model
public
Funding description
Not recorded
Cost
Not recorded
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

15 source dossiers

Davis, 'The Effect of Driving Restrictions on Air Quality in Mexico City', Journal of Political Economy 116(1), 2008, pp. 38-81 econpapers.repec.org · 8 linked claims

Open original source ↗

Stable source ID
src-ace305ebc8ebcd24
Publisher
Name not classified · econpapers.repec.org
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2024-04-28
Content hash
No captured content hash
Locator
Open the recorded source note

The load-bearing null result, abstract verbatim: 'In 1989, the government of Mexico City introduced a program, Hoy No Circula, that bans most drivers from using their vehicles one weekday per week on the basis of the last digit of the vehicle's license plate... Across pollutants and specifications there is no evidence that the restrictions have improved air quality. Evidence from additional sources indicates that the restrictions led to an increase in the total number of vehicles in circulation as well as a change in composition toward high-emissions vehicles.' Publisher page journals.uchicago.edu/doi/10.1086/529398; the author's own copy is at faculty.haas.berkeley.edu/ldavis/Davis%20JPE%202008.pdf but did not render from this desk, so the abstract was verified against this indexed mirror.

Descriptive only — not page/paragraph exact
Claims linked
Davis, 'Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City', Scientific Reports 7:41652, 2017 pmc.ncbi.nlm.nih.gov · 6 linked claims

Open original source ↗

Stable source ID
src-78b678356a3b5670
Publisher
Name not classified · pmc.ncbi.nlm.nih.gov
Type / language
web-page · language not classified
Published
2017-02-02
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2025-03-02
Content hash
No captured content hash
Locator
Open the recorded source note

Dates the Saturday extension and grades it: 'Mexico City's driving restrictions were expanded to include Saturdays on July 5th, 2008.' and 'Overall, there is little evidence that the program expansion improved air quality.' Also the sentence this entry uses on enforcement: 'City police vigorously enforce the restrictions and vehicles violating the ban are easy to spot. Drivers caught violating the rules must pay a hefty fine and their vehicles are impounded for 48 hours.'

Descriptive only — not page/paragraph exact
Claims linked
Gallego, Montero and Salas, 'The effect of transport policies on car use: Evidence from Latin American cities', Journal of Public Economics 107, 2013, pp. 47-62 econpapers.repec.org · 4 linked claims

Open original source ↗

Stable source ID
src-1aed7de45827ff4b
Publisher
Name not classified · econpapers.repec.org
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Independently dates the programme to November 1989 ('the driving restriction program introduced in Mexico-City in November of 1989') and carries the study's method and direction in its abstract: hourly carbon monoxide records, and household responses 'not only ultimately unfortunate—more cars on the road and higher pollution levels—but also remarkably similar … on how fast households adjust their stock of vehicles, when they do.' The eleven-month figure sits in the paper's body behind Elsevier's paywall; the open working-paper version cited below carries it in its own abstract.

Descriptive only — not page/paragraph exact
Claims linked
Gallego, Montero and Salas, 'The Effect of Transport Policies on Car Use: Theory and Evidence from Latin American Cities', Documentos de Trabajo 407, Instituto de Economia, PUC Chile (2011) — open working-paper version ideas.repec.org · 2 linked claims

Open original source ↗

Stable source ID
src-7689b587dad366e5
Publisher
Name not classified · ideas.repec.org
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The open working-paper version of the Journal of Public Economics article, cited for the figure the published abstract does not carry. Its abstract states verbatim: 'an expected short-run response followed by a rapid (before 11 months) increase in the stock of vehicles.'

Descriptive only — not page/paragraph exact
Claims linked
Guerra and Millard-Ball, 'Getting around a license-plate ban: behavioral responses to Mexico City's driving restriction', Transportation Research Part D 55, 2017 sciencedirect.com · 4 linked claims

Open original source ↗

Stable source ID
src-344cf108280f6545
Publisher
Name not classified · sciencedirect.com
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
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Open archived copy ↗ · 2022-07-29
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The published record of the fourth peer-reviewed study. The publisher page blocks automated readers (403 on 2026-07-26 and again on 2026-08-27), so this entry cites the study from its abstract and from the author-hosted preprint below, not from a full read of the journal version. Publication date from Crossref (print issue August 2017, DOI 10.1016/j.trd.2017.06.027).

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Claims linked
Guerra and Millard-Ball, 'Getting around a license-plate ban' — author preprint, UCLA ITS (June 2017) millardball.its.ucla.edu · 4 linked claims

Open original source ↗

Stable source ID
src-12e4c5d7271cd7b2
Publisher
Name not classified · millardball.its.ucla.edu
Type / language
pdf · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
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No local capture recorded
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No archived copy linked
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The author-hosted open preprint of the Transportation Research Part D article, and the copy this entry was checked against. Abstract, verbatim: 'we reject the prevailing theory that its lack of success is due to perverse incentives for households to buy second cars. Instead, we highlight the range of other, less costly ways that people adjust behavior to avoid the restrictions.' The highlights add: 'Finds that households avoid ban by shuffling weekly travel routines.'

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SEDEMA, Ciudad de Mexico — Programa Hoy No Circula sedema.cdmx.gob.mx · 2 linked claims

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Stable source ID
src-7d81a556f40673ac
Publisher
Name not classified · sedema.cdmx.gob.mx
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2026-01-13
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The operator's own programme page and the correct citation for the current rules. It could not be read from this desk on either check (503 on 2026-07-26, connection failure on 2026-08-27); the rules this entry states rest on CAMe's description of the same programme and on El Universal's continuously updated rules page, both below.

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Comision Ambiental de la Megalopolis — 'El Programa Hoy No Circula que aplica en la Zona Metropolitana del Valle de Mexico' gob.mx · 2 linked claims

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Stable source ID
src-debbf8eec8ff1891
Publisher
Name not classified · gob.mx
Type / language
web-page · language not classified
Published
2025-04-01
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2025-04-01
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CAMe's own description of the programme, comunicado 20/2025 of 1 April 2025, issued to knock down false rumours of extra restrictions: 'el programa Hoy No Circula que aplica en las 16 alcaldias de la Ciudad de Mexico y en 18 municipios conurbados del Estado de Mexico, no ha tenido cambios' ('the Hoy No Circula programme that applies in the 16 boroughs of Mexico City and 18 adjoining municipalities of the State of Mexico has not changed'). Carries the hologram rule verbatim: 'Los vehiculos con holograma 1 no circulan dos sabados del mes segun su terminacion, mientras que los vehiculos con holograma 2 no circulan ningun sabado del mes. Los vehiculos electricos e hibridos con holograma tipo Exento y aquellos con holograma 0 y 00 pueden circular todos los dias de la semana.' Direct fetch meets a challenge wall; read in full through a text-extraction proxy on 2026-08-27.

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Claims linked
Comision Ambiental de la Megalopolis — comunicado of 25 April 2026 maintaining the Fase I ozone contingency into the following Sunday gob.mx · 3 linked claims

Open original source ↗

Stable source ID
src-ad142b48dbcb7470
Publisher
Name not classified · gob.mx
Type / language
web-page · language not classified
Published
2026-04-25
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
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A live Fase I communique, read in full through a text-extraction proxy on 2026-08-27: CAMe 'informa que se mantiene la Fase I de contingencia ambiental atmosferica por ozono en la Zona Metropolitana del Valle de Mexico (ZMVM) y sus medidas para el dia de manana, domingo 26 de abril del 2026'. It shows who declares a contingency and that a declaration reaches even normally exempt cars: private vehicles with hologram 0 and 00, yellow sticker, plates ending 5 or 6, must stop from 5:00 to 22:00, while electric and hybrid vehicles and motorcycles stay exempt. Dated from the page's own text — it announces measures 'para el dia de manana, domingo 26 de abril del 2026', so it was issued on 25 April 2026; the operator's parallel communique 34/2026 of the same day carries the activation.

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Claims linked
El Horizonte — 'Activa CAME quinta contingencia ambiental por ozono en el ano' (25 April 2025) elhorizonte.mx · 3 linked claims

Open original source ↗

Stable source ID
src-988c68fa7ef99f12
Publisher
Name not classified · elhorizonte.mx
Type / language
web-page · language not classified
Published
2025-04-25
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
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No local capture recorded
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No archived copy linked
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Carries the 2025 count and its dates, verbatim: 'Esta es la quinta contingencia ambiental por ozono tras las del 26 de febrero, 18 de marzo, 1 de abril y 23 de abril, mientras que el 1 de enero se dio por mala calidad del aire y particulas suspendidas' ('This is the fifth ozone environmental contingency after those of 26 February, 18 March, 1 April and 23 April, while the one of 1 January was for bad air quality and suspended particles'). Also carries the trigger reading (159 ppb of ozone at the Ajusco Medio station at 15:00) and the threshold as reported to the public: 150 air-quality-index points.

Descriptive only — not page/paragraph exact
Claims linked
El Universal — 'De Un Dia sin Auto a Hoy No Circula sabatino. Cronologia' (1 July 2008) archivo.eluniversal.com.mx · 7 linked claims

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Stable source ID
src-eae82745034bd9a6
Publisher
Name not classified · archivo.eluniversal.com.mx
Type / language
web-page · language not classified
Published
2008-07-01
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
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Open the recorded source note

A national newspaper's chronology of the programme, drawn from the then-DF environment secretariat. 1984: 'Arranca como iniciativa ciudadana "Un dia Sin Auto" … impulsada por la agrupacion ecologista "Mejora tu Ciudad"' (a voluntary citizens' initiative by an ecologist group). 1989: 'Aplica de manera oficial el programa Hoy No Circula (HNC) para la temporada invernal' (official, for the winter season). 1990: 'Extienden el programa … de manera permanente, ya no solo para la temporada invernal. Se establece el programa de Verificacion Vehicular' (made permanent, vehicle verification established). 2008: 'Lanzan para el 5 de julio el inicio de las restricciones' (Saturday restrictions launched for 5 July).

Descriptive only — not page/paragraph exact
Claims linked
El Financiero — 'Hoy No Circula: origen, historia y por que se instauro este programa en la CDMX' elfinanciero.com.mx · 3 linked claims

Open original source ↗

Stable source ID
src-afdaf4d2258b3ff4
Publisher
Name not classified · elfinanciero.com.mx
Type / language
web-page · language not classified
Published
2023-03-27
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2026-06-09
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Origin piece. The text served today carries the start date verbatim: 'El programa Hoy No Circula inicio el 20 de noviembre de 1989 ante una emergencia ambiental similar a la actual' ('began on 20 November 1989 during an environmental emergency similar to the current one'). The fuller history this entry once quoted from the same address — the 'Un Dia sin Auto' name and the 1990 accord — is no longer in the served text; those facts now rest on El Universal's chronology above.

Descriptive only — not page/paragraph exact
Claims linked
El Universal — Hoy No Circula rules page (continuously updated reference) eluniversal.com.mx · background

Open original source ↗

Stable source ID
src-3d24c58386c85927
Publisher
Name not classified · eluniversal.com.mx
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
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Open the recorded source note

A continuously updated rules-and-lookup page, so it publishes no date of its own. Checked on 2026-08-27, when it showed that day's restriction live: green sticker, plates ending 1 and 2, holograms 1 and 2, 5:00 to 22:00, applying in the 16 boroughs of Mexico City and 18 of the State of Mexico's 125 municipalities — the programme running unchanged in its thirty-seventh year.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
El Universal — vehicle verification rules page (continuously updated reference) eluniversal.com.mx · 2 linked claims

Open original source ↗

Stable source ID
src-8d6241d5417f2cf6
Publisher
Name not classified · eluniversal.com.mx
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

A continuously updated reference page, so it publishes no date of its own; checked on 2026-08-27. Carries the semester rhythm behind the holograms: each sticker colour has two verification windows a year (for example green, plates 1 and 2: April–May and October–November 2026), and hologram 0 is listed with 'vigencia semestral' — six-month validity.

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Claims linked
adn40 — photo-enforcement cameras that sanction Hoy No Circula in CDMX (4 September 2025) adn40.mx · 1 linked claim

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Stable source ID
src-6d20cebdd4a72790
Publisher
Name not classified · adn40.mx
Type / language
web-page · language not classified
Published
2025-09-04
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-27
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2025-09-06
Content hash
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The camera question, media-grade only: 'Estos dispositivos no solo sancionan a quienes exceden la velocidad, tambien detectan conductores que circulan sin respetar las restricciones ambientales' ('These devices do not only sanction those exceeding the speed limit, they also detect drivers circulating without respecting the environmental restrictions'), on a network described as more than 140 fixed cameras and radars plus mobile units, after CDMX restored economic photo-fines alongside the 2019 points-based fotocivicas. No official source confirming camera detection of Hoy No Circula was reachable, so this is not claimed in the snippet.

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.