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YEAR-OVER-YEAR CRASH REPORT · QUINCY, MA · SEPTEMBER 2023
Purpose: Machine-readable JSON endpoint for AI agents, LLMs, researchers, and programmatic consumers. Returns all underlying crash data and AI-generated commentary without HTML.
Authentication: None required. Public endpoint.
GET: https://thatcarhitme.com/api/crash-data/reports/data/massachusetts/quincy/september-2023-report
Monthly Traffic Safety Analysis
189 CRASHES IN
QUINCY, MA
SEPTEMBER 2023
QUINCY experienced an increase in total crashes, rising from 170 in September 2022 to 189 in September 2023, representing an 11.18% increase. Notably, the city recorded 2 fatalities in September 2023, compared to zero fatalities in the same month the previous year.
189
▲ 11.2%was 170
Total Crash Events
2
Persons Killed
49
▲ 22.5%was 40
Persons Injured
17
▼ -26.1%was 23
Hit-and-Run Crashes
Note: "Persons Killed" (2) counts individual fatalities across all crash events. "Fatal" in the severity table below (2) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 6 crashes with unreported severity are not shown in the severity breakdown.
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Overall, crash data for QUINCY shows an upward trend year-over-year. Total crashes increased by 11.18%, from 170 in September 2022 to 189 in September 2023. Additionally, total fatalities rose from 0 to 2, and total injuries increased by 22.5%, from 40 to 49, during this period.
17
Hit-and-Run Crashes — September 2023
▼ -26.1% vs prior (23)
Hit-and-run incidents decreased year-over-year, dropping from 23 crashes in September 2022 to 17 crashes in September 2023. This change is reflected in the hit-and-run rate, which decreased from 13.5% to 9% of all crashes.
Vulnerable Road User Casualties
0
Pedestrians Killed
2
Cyclists Killed
0
Motorists Killed
4
Pedestrians Injured
0
Cyclists Injured
45
Motorists Injured
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The temporal patterns of crashes shifted year-over-year, with Friday becoming the peak day for crashes in September 2023 with 34 incidents, compared to Monday with 29 crashes in September 2022. The peak crash hour also changed, moving from 12p with 19 crashes in September 2022 to 4p with 16 crashes in September 2023. Furthermore, crashes occurring at 8a saw a notable increase from 4 to 16 incidents.
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Crash date field aggregated by weekday
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
The severity distribution of crashes saw significant changes, most notably with fatal crashes increasing from 0 in September 2022 to 2 in September 2023, resulting in a fatal crash rate of 1.06%. Serious injury crashes decreased from 5 (2.9% of crashes) to 1 (0.5% of crashes) year-over-year. Meanwhile, minor injury crashes increased in count from 22 to 26, and no-injury crashes rose from 123 to 145, increasing their proportion from 72.4% to 76.7% of all incidents.
Outcome by Severity (Crash Events)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · KABCO injury classification scale
Severity Distribution (Crash Events)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Most severe injury per crash record
Top Contributing Factors
Inattention remained the leading contributing factor, increasing from 50 incidents in September 2022 to 57 in September 2023, a 14% rise. Factors such as 'Failed to yield right of way' and 'Followed too closely' also saw increases in crash counts, rising by 4 incidents each. Notably, 'Failure to keep in proper lane or running off road' increased by 6 incidents (150% change in count) from 4 to 10, and 'Visibility obstructed' increased by 6 incidents (600% change in count) from 1 to 7. Conversely, crashes attributed to 'Disregarded traffic signs, signals, road markings' decreased by 3 incidents, a 60% reduction in count.
Officer-Reported Primary Contributing Cause
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
Crash conditions saw a notable shift towards adverse road surfaces, with crashes on wet roads increasing from 28 (16.5% of crashes) in September 2022 to 51 (27.0% of crashes) in September 2023. Concurrently, crashes on dry roads decreased from 140 to 137. In terms of lighting, daylight crashes increased from 115 to 140, while crashes in dark-lighted roadway conditions decreased from 43 to 36.
Weather
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Weather condition at time of crash
Lighting
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Lighting condition field
Road Surface
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes increased from 329 to 367 year-over-year. Toyota remained the most frequently involved vehicle make, increasing its count from 60 to 70, while Chevrolet involvement decreased from 24 to 19. Among persons involved, there was a notable increase in the 16-20 age group (from 22 to 35) and the 65+ age group (from 42 to 58).
Top Vehicle Makes (367 vehicles)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Vehicle unit records
62 persons with unknown or unrecorded age excluded from age chart.
Sex Distribution (443 persons with recorded sex)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Person-level records linked to crash events
Speed Limit Zones
Crashes in 25 MPH speed zones saw an increase from 95 incidents in September 2022 to 118 in September 2023. Notably, both of the fatal crashes in September 2023 occurred in lower speed zones, with one at 15 MPH and another at 25 MPH. In contrast, no fatal crashes were recorded in any speed zone during September 2022.
Fatal crashes by zone: 15 mph: 1 of 2 (50%) · 25 mph: 1 of 118 (0.847%)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Posted speed limit at crash location
Data Sources & Methodology
Primary Data Source
All crash data in this report is sourced from Massachusetts Crash Data (MassDOT CDV), accessed programmatically via the Arcgis_yearly Open Data API (SODA). This dataset contains official police-reported motor vehicle traffic crash records maintained by the reporting jurisdiction's law enforcement agency. Records are published to the open data portal by the municipality and are subject to the portal's terms of use.
Data Retrieval
- Access method: Arcgis_yearly Open Data API (SoQL queries)
- Data format: Structured JSON via REST API
- Record types queried: Crash events, person records, and vehicle unit records
- Date filter applied: 2023-09-01 through 2023-09-30
- Report generated: June 21, 2026
Data Coverage
- Reporting period: 2023-09-01 through 2023-09-30 (30 days)
- Geographic scope: QUINCY, MA
- Total crash records analyzed: 189
- Total persons involved: 494
- Total vehicles involved: 367
Analytical Methodology
- Severity classification: Uses the KABCO injury scale (K=Fatal, A=Incapacitating injury, B=Non-incapacitating injury, C=Possible injury, O=No injury/property damage only), the standard classification in U.S. Model Minimum Uniform Crash Criteria (MMUCC). Severity is assigned per crash event based on the most severe injury in that crash. A single fatal crash (K) may involve multiple fatalities; therefore the "Persons Killed" count in the headline KPIs may differ from the "Fatal" crash count in the severity breakdown.
- Contributing factors: Reflect the officer-determined primary contributory cause recorded at the time of the crash report. These are preliminary determinations and may not reflect final investigation findings.
- Hit-and-run classification: Based on the hit-and-run indicator field in the official crash report, as determined by the responding officer at the scene.
- Temporal analysis: Day-of-week and hour-of-day distributions are computed from the crash date/time timestamp in each record.
- Demographics: Age and sex distributions are drawn from person-level records linked to each crash event. A single crash may involve multiple persons.
- Vehicle data: Make information is drawn from vehicle unit records linked to each crash event.
- AI commentary: Narrative sections are generated by Google Gemini (large language model) based on the structured data. Commentary is descriptive, not predictive, and should not be interpreted as expert opinion.
Limitations & Disclaimers
- Only crashes reported to and documented by law enforcement are included. Minor incidents, unreported crashes, and near-misses are not captured in this dataset.
- Data reflects conditions at the time of the initial police report and may be subject to subsequent corrections, reclassifications, or supplements by the reporting agency.
- Open data portal records may experience a publication lag - recently occurring crashes may not yet appear in the dataset at the time of report generation.
- AI-generated commentary is produced by a large language model and is intended to highlight patterns in the data. It does not constitute legal, medical, or professional analysis.
- Percentages are calculated from reported data and are subject to rounding.
Non-Affiliation Disclosure
This report is produced independently by ThatCarHitMe.com (Injuria.ai). It is not affiliated with, endorsed by, or produced in partnership with any law enforcement agency, municipal government, state department of transportation, or the National Highway Traffic Safety Administration (NHTSA). Data is sourced from publicly available government open data portals.
Data License
The underlying crash data is provided under the municipality's Open Data Terms of Use and is made available to the public for unrestricted use. This analysis and report is © 2026 Injuria.ai and may be cited with attribution using the suggested citation below.
Corrections & Feedback
If you believe any data in this report is inaccurate or have questions about our methodology, please contact: data@injuria.ai. We are committed to accuracy and will issue corrections promptly.
Suggested Citation
ThatCarHitMe.com (Injuria.ai). "QUINCY, MA Crash Intelligence Report: September 2023." Published June 21, 2026. Reporting period: 2023-09-01 to 2023-09-30. Data source: Massachusetts Crash Data (MassDOT CDV), Arcgis_yearly Open Data. Available at: https://thatcarhitme.com/crash-data/massachusetts/quincy/september-2023-report
About the Publisher
ThatCarHitMe.com is a crash data intelligence platform developed by Injuria.ai, a legal technology company specializing in traffic safety analytics. We aggregate and analyze publicly available government crash data to produce structured intelligence reports for communities, researchers, journalists, and legal professionals. Our reports combine programmatic data retrieval from official open data portals with AI-assisted narrative analysis.
Questions about this report's data or methodology: data@injuria.ai
ThatCarHitMe.com · An Injuria.ai Company
ThatCarHitMe.com
An Injuria.ai Company
Crash Data Intelligence
Data: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly
Period: 2023-09-01 – 2023-09-30
Generated: June 21, 2026 · All rights reserved