1001 Smart Cities
🇺🇸 Boston

Vision Zero Boston: 25 mph default limit and open crash records

🤖 AI-generated summary · ◆ 1 sourced claim · 🔎 Last verified

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.

1 sourced claim on this page, none individually verified yet — turn on “Sources in the text” to see each one.

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

✎ Corrected 20 Aug 2026 Publication date recorded for 1 source. What changed →

Cutting the default limit from 30 to 25 mph barely moved the average driver — mean speeds fell 0.3 percent, not statistically significant. But the odds of a car exceeding 35 mph fell 29.3 percent.

Outcome🔄 Ongoing
Evidence🔬 Peer-reviewed
what does this mean?The strongest source behind this entry is an independent peer-reviewed or academic study. It grades who did the looking — not how well the project went. All four grades →
Run byCity of Boston — Boston Transportation Department (Streets Cabinet), with Boston EMS and the Department of Innovation and Technology on the data
Scale🏙️ City-wide
CostTraffic calming funded at $15M in the enacted FY26 budget and $13M in the FY27 proposal
FundingCity of Boston capital and operating budget

Part of 1001 Smart Cities — 1,167 documented projects · 🏙️ 9 more in Boston · 🚦 Traffic management guide · 🚲 Mobility projects

Boston pledged in 2015 to end traffic deaths by 2030. Using a 2016 state law, it cut the default limit on city-owned streets from 30 to 25 mph on 9 January 2017 and posts 20 mph in slow-street zones. Every crash Boston EMS attends since 2015 is published as a public-domain dataset and map, updated monthly.

Live 📅 since 2015

📊 Impact

The speed-limit change is one of the few urban limit reductions with a controlled evaluation. A peer-reviewed study in Injury Prevention compared speeds at Boston sites with control sites in Providence, Rhode Island, before and after: mean speeds fell 0.3 percent, which was not statistically significant (p=0.065), while the odds of a vehicle exceeding 25, 30 and 35 mph fell 2.9, 8.5 and 29.3 percent. The average driver barely changed; the fastest ones did. The programme's own goal is not on track — the city says Boston still sees 10+ traffic deaths and thousands of injuries a year.

🎓 Lesson

The measurable effect of a citywide limit change sat in the tail, not the mean: mean speeds barely moved while the odds of driving above 35 mph fell by nearly a third. And the rule stops where city ownership does — Boston's own notice tells drivers to watch posted signs on state-owned roads, which the 25 mph default does not touch.

🚲 MobilityTraffic managementSafety & securityOpen data

Sources

↗ City of Boston — 25 in Boston (authority)Updated 30 October 2025Primary for the date and the scope limit. The default limit took effect 'January 9, 2017' on city-owned streets without posted limits. Also carries the jurisdictional caveat in the city's own words: 'This change only affects roads the City owns. Please pay attention to posted signs on state-owned roads.' The page does not name the enabling statute; that is sourced separately.
↗ M.G.L. c. 90 §17C — 25 mph in thickly settled districts (statute)The enabling authority. The Municipal Modernization Act of August 2016 let municipalities that accept §17C lower the statutory limit from 30 to 25 mph in thickly settled or business districts without MassDOT approval; Boston accepted it citywide, effective 9 January 2017. MassDOT's guidance page on speed limits in thickly settled districts covers the same mechanism.
↗ Hu & Cicchino, Injury Prevention 2020;26:99-102 (peer-reviewed)Published March 2020 archived copyThe controlled evaluation the entry rests on. Method: vehicle speeds collected 'at sites in Boston where the speed limit was lowered, and at control sites in Providence, Rhode Island, where the speed limit remained unchanged, before and after the speed limit change in Boston', with a log-linear model for mean speed and separate logistic models for exceedance. Result, verbatim: 'The speed limit reduction was associated with a 0.3% reduction in mean speeds (p=0.065), and reductions of 2.9%, 8.5% and 29.3% in the odds of vehicles exceeding 25 mph, 30 mph and 35 mph, respectively.' Neither the abstract nor the IIHS record states the number of sites. Note the authors are staff of the Insurance Institute for Highway Safety, an insurance-industry-funded body; the paper itself is peer-reviewed in a BMJ journal.
↗ IIHS — plain-language summary of the same study (research body)Published 28 August 2018Second reading of the same numbers: 'After Boston lowered the default speed limit to 25 mph, the estimated odds of a vehicle exceeding 35 mph fell 29.3%', with 8.5 percent for 30 mph and 2.9 percent for 25 mph, Providence as control, measured around the 9 January 2017 change, at arterial, collector and local road sites.
↗ Analyze Boston — Vision Zero Crash Records dataset (authority, open data)Published 1 May 2018The data layer, and the licence answer: 'Open Data Commons Public Domain Dedication and License (PDDL)'. Records run 1 January 2015 through 30 June 2026, updated monthly. The source is EMS, not police: 'Motor Vehicle Accidents (MVAs) provided in this dataset are Boston EMS incidents with a documented patient encounter that were identified as an MVA during the 9-1-1 call taking process, by crews on scene, or incidents where the injury cause is documented as related to an MVA', compiled by the Department of Innovation and Technology from the Computer-Aided Dispatch (911) system. The page also flags a break in the series: 'In June of 2024, Boston EMS transitioned to a new patient record system… Differences in MVA rates before and after June 2024 are reflective of this new reporting methodology and should not be interpreted as a change in motor vehicle incidents.'
Show 8 more sourcesShow fewer
↗ Analyze Boston — Vision Zero Fatality Records dataset (authority, open data)Published 23 July 2018The other half of the split: fatalities are 'compiled by the Department of Innovation and Technology from the 911 system and verified by Boston Police Department', 1 January 2015 to present, monthly, also under the Open Data Commons Public Domain Dedication and License (PDDL).
↗ Vision Zero Crash Records Map — about page (authority)What the public map does and does not show. Records cover 'date, time, location, and type of crash for incidents requiring public safety response which may involve injuries or fatalities', but 'do not indicate the severity of specific crashes or whether medical care was provided'; 'Each incident is included only once regardless of the number of individuals involved'; the timestamp is when response was dispatched, 'not the crash itself'; and the city states errors may be present and the information may not be complete.
↗ City of Boston — Vision Zero (authority)The goal and the shortfall in the same place: the programme aims to 'eliminate fatal and severe traffic crashes in the City by 2030', while the city reports it 'currently experiences 10+ fatalities, hundreds of pedestrian and cyclist injuries, and thousands of driver injuries on city streets every year'. Also hosts the injury crash map and the by-mode dashboards.
↗ City of Boston — Neighborhood Slow Streets (authority)Updated 30 October 2025The 20 mph layer: traffic calming built in 15 neighbourhoods, where 'the speed limit on its residential streets will be 20 mph'. Piloted in the Talbot Norfolk Triangle in Dorchester and Stonybrook in Jamaica Plain in late 2017; renamed Safety Surge in 2023. No verified count of formally designated statutory 20 mph safety zones was found, so none is claimed.
↗ Streetsblog Massachusetts — Safety Surge announcement, May 2023 (press)Published 22 May 2023What changed under the administration that took office in November 2021: the slow-streets programme was rebuilt as Safety Surge with more than $12 million in the FY24 budget, roughly 10 speed-hump zones and 25 to 30 intersection redesigns a year, prioritised on crash history and demographics.
↗ Streetsblog Massachusetts — FY27 budget cuts, April 2026 (press)Published 22 April 2026The currency counterweight. Safety Surge falls from '$15 million in enacted FY26 budget' to '$13 million in FY27 proposal', and more than a dozen street-safety capital lines go to zero, including Roxbury Resilient Transportation Corridors ($32.5M to $0), Dedicated Bus Lanes ($13.5M to $0) and Commonwealth Avenue Phases 3, 3B and 4 ($13.5M to $0). Delivery, not just budget, is the issue: 'Boston's Streets Cabinet spent only $450,000 on speed humps in the past year – less than 10 percent of what the FY26 budget had proposed.'
↗ LivableStreets Alliance decade review, June 2026, via Streetsblog Massachusetts (independent)Published 26 June 2026The only whole-programme assessment found outside the city; no municipal auditor review exists. The advocacy research group analysed a decade of crash data across Boston, Cambridge and Somerville, finding progress that was 'uneven at times'. On Boston specifically: 'Boston, by contrast, focused its resources on streets with the highest rates of injuries', citing Tremont Street, Centre Street in West Roxbury and the Common and Public Garden roadways. The report's standout is Somerville, with no fatal crashes since 2022 — not Boston.
↗ Boston Region MPO — High-Injury Network methodology (regional authority)Confirms what makes Boston's series unusual and where the city's writ ends. Regional high-injury analysis draws on MassDOT's IMPACT portal, whose 'crash database currently relies on information from police reports, but some cities, like Boston, also collect data from city EMS services'. It also records that roads on the network are owned variously by municipalities, MassDOT or the Department of Conservation and Recreation. No source gives a Boston-specific share of state-owned roads, so the entry claims none.

📅 How old is the evidence?

Two clocks, kept apart: when this entry’s sources were published, and what has happened to its record in the atlas. Documented span: since 2015. 7 of 13 sources carry a publication date, from 1 May 2018 to 26 June 2026.

When the sources were published

  1. City of Boston · city governmentAnalyze Boston — Vision Zero Crash Records dataset (authority, open data)
  2. City of Boston · city governmentAnalyze Boston — Vision Zero Fatality Records dataset (authority, open data)
  3. Insurance Institute for Highway Safety (IIHS) · researchIIHS — plain-language summary of the same study (research body)
  4. Insurance Institute for Highway Safety (IIHS) · researchHu & Cicchino, Injury Prevention 2020;26:99-102 (peer-reviewed)
  5. Streetsblog Massachusetts · pressStreetsblog Massachusetts — Safety Surge announcement, May 2023 (press)
  6. Streetsblog Massachusetts · pressStreetsblog Massachusetts — FY27 budget cuts, April 2026 (press)
  7. Streetsblog Massachusetts · pressLivableStreets Alliance decade review, June 2026, via Streetsblog Massachusetts (independent)

Every source, with links ↑

What happened to this record

  1. Sources last read
  2. Publication date recorded for 1 source
  3. Entered the record

Every revision, permanent →

Show your work What this page rests on and what it can’t tell you · all 1 claims with their sources · the forensic record

Evidence Passport · public beta 1 addressable claim, 13 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 1

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-8708cd5a91cece5a quantitative
mean speeds fell 0.3 percent, which was not statistically significant (p=0.065), while the odds of a vehicle exceeding 25, 30 and 35 mph fell 2.9, 8.5 and 29.3 percent
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The study compared speeds at Boston sites with control sites in Providence, Rhode Island, before and after the limit change.
Caveat
The programme's own goal is not on track — the city says Boston still sees 10+ traffic deaths and thousands of injuries a year.

Sources carrying this claim

  1. Hu & Cicchino, Injury Prevention 2020;26:99-102 (peer-reviewed)
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 2026-08-20-source-dates-corrected effective 2026-07-26 · created 2026-08-20

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

sha256:641abc44cbc762f2c9520bbb17a1f848a7fecc2fea17cb8aae59b498c773e1f3
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
1
of 1 claims mapped
13
source dossiers
6
publication dates recorded
1
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
City of Boston — Boston Transportation Department (Streets Cabinet), with Boston EMS and the Department of Innovation and Technology on the data
Actor types
city-government
Funding model
public
Funding description
City of Boston capital and operating budget
Cost
Traffic calming funded at $15M in the enacted FY26 budget and $13M in the FY27 proposal
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

13 source dossiers

City of Boston — 25 in Boston (authority) boston.gov · background

Open original source ↗

Stable source ID
src-277ee9eeda224d8f
Publisher
Name not classified · boston.gov
Type / language
web-page · language not classified
Published
Not recorded
Updated
2025-10-30
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Primary for the date and the scope limit. The default limit took effect 'January 9, 2017' on city-owned streets without posted limits. Also carries the jurisdictional caveat in the city's own words: 'This change only affects roads the City owns. Please pay attention to posted signs on state-owned roads.' The page does not name the enabling statute; that is sourced separately.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
M.G.L. c. 90 §17C — 25 mph in thickly settled districts (statute) malegislature.gov · background

Open original source ↗

Stable source ID
src-44b208c02944e47d
Publisher
Name not classified · malegislature.gov
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The enabling authority. The Municipal Modernization Act of August 2016 let municipalities that accept §17C lower the statutory limit from 30 to 25 mph in thickly settled or business districts without MassDOT approval; Boston accepted it citywide, effective 9 January 2017. MassDOT's guidance page on speed limits in thickly settled districts covers the same mechanism.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Hu & Cicchino, Injury Prevention 2020;26:99-102 (peer-reviewed) iihs.org · 1 linked claim

Open original source ↗

Stable source ID
src-e87a8c0c4939d965
Publisher
Name not classified · iihs.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
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2026-06-08
Content hash
No captured content hash
Locator
Open the recorded source note

The controlled evaluation the entry rests on. Method: vehicle speeds collected 'at sites in Boston where the speed limit was lowered, and at control sites in Providence, Rhode Island, where the speed limit remained unchanged, before and after the speed limit change in Boston', with a log-linear model for mean speed and separate logistic models for exceedance. Result, verbatim: 'The speed limit reduction was associated with a 0.3% reduction in mean speeds (p=0.065), and reductions of 2.9%, 8.5% and 29.3% in the odds of vehicles exceeding 25 mph, 30 mph and 35 mph, respectively.' Neither the abstract nor the IIHS record states the number of sites. Note the authors are staff of the Insurance Institute for Highway Safety, an insurance-industry-funded body; the paper itself is peer-reviewed in a BMJ journal.

Descriptive only — not page/paragraph exact
Claims linked
IIHS — plain-language summary of the same study (research body) iihs.org · background

Open original source ↗

Stable source ID
src-f897902133055f3b
Publisher
Name not classified · iihs.org
Type / language
web-page · language not classified
Published
2018-08-28
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Second reading of the same numbers: 'After Boston lowered the default speed limit to 25 mph, the estimated odds of a vehicle exceeding 35 mph fell 29.3%', with 8.5 percent for 30 mph and 2.9 percent for 25 mph, Providence as control, measured around the 9 January 2017 change, at arterial, collector and local road sites.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Analyze Boston — Vision Zero Crash Records dataset (authority, open data) data.boston.gov · background

Open original source ↗

Stable source ID
src-49e78972da8619cf
Publisher
Name not classified · data.boston.gov
Type / language
web-page · language not classified
Published
2018-05-01
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The data layer, and the licence answer: 'Open Data Commons Public Domain Dedication and License (PDDL)'. Records run 1 January 2015 through 30 June 2026, updated monthly. The source is EMS, not police: 'Motor Vehicle Accidents (MVAs) provided in this dataset are Boston EMS incidents with a documented patient encounter that were identified as an MVA during the 9-1-1 call taking process, by crews on scene, or incidents where the injury cause is documented as related to an MVA', compiled by the Department of Innovation and Technology from the Computer-Aided Dispatch (911) system. The page also flags a break in the series: 'In June of 2024, Boston EMS transitioned to a new patient record system… Differences in MVA rates before and after June 2024 are reflective of this new reporting methodology and should not be interpreted as a change in motor vehicle incidents.'

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Analyze Boston — Vision Zero Fatality Records dataset (authority, open data) data.boston.gov · background

Open original source ↗

Stable source ID
src-d9c5e1dcd3dfaad0
Publisher
Name not classified · data.boston.gov
Type / language
web-page · language not classified
Published
2018-07-23
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The other half of the split: fatalities are 'compiled by the Department of Innovation and Technology from the 911 system and verified by Boston Police Department', 1 January 2015 to present, monthly, also under the Open Data Commons Public Domain Dedication and License (PDDL).

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Vision Zero Crash Records Map — about page (authority) apps.boston.gov · background

Open original source ↗

Stable source ID
src-2091caf23d60f367
Publisher
Name not classified · apps.boston.gov
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

What the public map does and does not show. Records cover 'date, time, location, and type of crash for incidents requiring public safety response which may involve injuries or fatalities', but 'do not indicate the severity of specific crashes or whether medical care was provided'; 'Each incident is included only once regardless of the number of individuals involved'; the timestamp is when response was dispatched, 'not the crash itself'; and the city states errors may be present and the information may not be complete.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
City of Boston — Vision Zero (authority) boston.gov · background

Open original source ↗

Stable source ID
src-954238c960d30854
Publisher
Name not classified · boston.gov
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The goal and the shortfall in the same place: the programme aims to 'eliminate fatal and severe traffic crashes in the City by 2030', while the city reports it 'currently experiences 10+ fatalities, hundreds of pedestrian and cyclist injuries, and thousands of driver injuries on city streets every year'. Also hosts the injury crash map and the by-mode dashboards.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
City of Boston — Neighborhood Slow Streets (authority) boston.gov · background

Open original source ↗

Stable source ID
src-6ef58f331c874ab0
Publisher
Name not classified · boston.gov
Type / language
web-page · language not classified
Published
Not recorded
Updated
2025-10-30
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The 20 mph layer: traffic calming built in 15 neighbourhoods, where 'the speed limit on its residential streets will be 20 mph'. Piloted in the Talbot Norfolk Triangle in Dorchester and Stonybrook in Jamaica Plain in late 2017; renamed Safety Surge in 2023. No verified count of formally designated statutory 20 mph safety zones was found, so none is claimed.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Streetsblog Massachusetts — Safety Surge announcement, May 2023 (press) mass.streetsblog.org · background

Open original source ↗

Stable source ID
src-f3911821984696a8
Publisher
Name not classified · mass.streetsblog.org
Type / language
web-page · language not classified
Published
2023-05-22
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

What changed under the administration that took office in November 2021: the slow-streets programme was rebuilt as Safety Surge with more than $12 million in the FY24 budget, roughly 10 speed-hump zones and 25 to 30 intersection redesigns a year, prioritised on crash history and demographics.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Streetsblog Massachusetts — FY27 budget cuts, April 2026 (press) mass.streetsblog.org · background

Open original source ↗

Stable source ID
src-ac9f6d10e15133b6
Publisher
Name not classified · mass.streetsblog.org
Type / language
web-page · language not classified
Published
2026-04-22
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The currency counterweight. Safety Surge falls from '$15 million in enacted FY26 budget' to '$13 million in FY27 proposal', and more than a dozen street-safety capital lines go to zero, including Roxbury Resilient Transportation Corridors ($32.5M to $0), Dedicated Bus Lanes ($13.5M to $0) and Commonwealth Avenue Phases 3, 3B and 4 ($13.5M to $0). Delivery, not just budget, is the issue: 'Boston's Streets Cabinet spent only $450,000 on speed humps in the past year – less than 10 percent of what the FY26 budget had proposed.'

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
LivableStreets Alliance decade review, June 2026, via Streetsblog Massachusetts (independent) mass.streetsblog.org · background

Open original source ↗

Stable source ID
src-4f38135112fb81cd
Publisher
Name not classified · mass.streetsblog.org
Type / language
web-page · language not classified
Published
2026-06-26
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The only whole-programme assessment found outside the city; no municipal auditor review exists. The advocacy research group analysed a decade of crash data across Boston, Cambridge and Somerville, finding progress that was 'uneven at times'. On Boston specifically: 'Boston, by contrast, focused its resources on streets with the highest rates of injuries', citing Tremont Street, Centre Street in West Roxbury and the Common and Public Garden roadways. The report's standout is Somerville, with no fatal crashes since 2022 — not Boston.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Boston Region MPO — High-Injury Network methodology (regional authority) ctps.org · background

Open original source ↗

Stable source ID
src-f60aa6949538a2cf
Publisher
Name not classified · ctps.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
2026-07-26
Dossier created
2026-08-20
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Confirms what makes Boston's series unusual and where the city's writ ends. Regional high-injury analysis draws on MassDOT's IMPACT portal, whose 'crash database currently relies on information from police reports, but some cities, like Boston, also collect data from city EMS services'. It also records that roads on the network are owned variously by municipalities, MassDOT or the Department of Conservation and Recreation. No source gives a Boston-specific share of state-owned roads, so the entry claims none.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
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

🇺🇸 Automated speed safety cameras (AB 645 pilot) · San Francisco Both gains sit in the tail: SFMTA reports ~72% less 10-mph-plus speeding; Boston's 25 mph limit cut the odds of exceeding 35 mph by 29.3%. 🇺🇸 Automated school-zone speed cameras (Vision Zero) · New York City New York reports 94% less speeding at its 2,000 camera sites; Boston changed the number on the sign and mean speeds moved 0.3%. 🇺🇸 Analyze Boston and the 2014 Open Data Executive Order · Boston Boston's crash record sits on the same portal: every crash EMS attends since 2015, published monthly under a public-domain deed.

Explore the wider context

🔑 Your Smart City Is Owned by Someone Else📖 ANPR (automatic number-plate recognition)📖 Automated speed enforcement (speed cameras)📖 Integrated command and control centre (ICCC)
📎 Cite this project

1001 Smart Cities (2026). “Vision Zero Boston: 25 mph default limit and open crash records” — Boston, United States. The Smart City Atlas. https://1001smartcities.org/projects/boston-vision-zero/ (last verified 2026-07-26). Data: CC BY 4.0.

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

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