ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · MASSACHUSETTS, 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/statewide/september-2023-report
Monthly Traffic Safety Analysis
11,737 CRASHES IN
MASSACHUSETTS, MA
SEPTEMBER 2023
In September 2023, Massachusetts recorded 11,737 total vehicle crashes, a 4.2% increase from the 11,266 crashes reported in September 2022. Despite the rise in total collisions, the number of fatalities decreased from 38 to 33 year-over-year. The most notable shift was a 23.3% increase in hit-and-run incidents, which rose from 870 to 1,073.
11,737
▲ 4.2%was 11,266
Total Crash Events
33
▼ -13.2%was 38
Persons Killed
3,781
▲ 2.0%was 3,706
Persons Injured
1,073
▲ 23.3%was 870
Hit-and-Run Crashes
Note: "Persons Killed" (33) counts individual fatalities across all crash events. "Fatal" in the severity table below (31) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 686 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 volume in Massachusetts trended upward in September 2023 compared to the same month in the prior year. Total crashes increased by 4.2%, rising from 11,266 to 11,737. While total injuries saw a slight increase of 2.0% (from 3,706 to 3,781), fatalities declined by 13.2%, from 38 to 33.
1,073
Hit-and-Run Crashes — September 2023
▲ 23.3% vs prior (870)
Hit-and-run incidents increased significantly in September 2023 compared to the previous year. The total count of hit-and-run crashes rose by 23.3%, from 870 in September 2022 to 1,073 in September 2023. The hit-and-run rate, representing the percentage of all crashes that were hit-and-runs, also trended upward, increasing from 7.7% to 9.1% year-over-year.
Vulnerable Road User Casualties
7
Pedestrians Killed
2
Cyclists Killed
24
Motorists Killed
0
Other Killed
129
Pedestrians Injured
131
Cyclists Injured
3,499
Motorists Injured
22
Other 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 remained largely consistent year-over-year. Friday was the peak day for crashes in both September 2023 (2,048 crashes) and September 2022 (2,045 crashes). The peak hour for collisions shifted slightly, from 3 PM in 2022 (1,011 crashes) to 4 PM in 2023 (1,008 crashes), indicating the afternoon commute remains the most common time for 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
While total crashes increased, the severity of those crashes showed a mixed picture. The number of fatal crashes decreased from 37 in September 2022 to 31 in September 2023, and serious injury crashes fell from 242 to 214. Conversely, crashes resulting in minor injuries increased by 7.5% (from 1,593 to 1,713), and non-injury crashes rose by 8.9% (from 7,597 to 8,271).
Severity is per crash event (most severe injury). 31 fatal crash events resulted in 33 persons killed.
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
The leading contributing factors for crashes remained consistent between September 2022 and September 2023, with 'No improper driving,' 'Inattention,' and 'Failed to yield right of way' as the top three in both periods. However, the count for 'Inattention' decreased by 4.7% from 1,655 to 1,578. In contrast, crashes attributed to 'Followed too closely' increased in count by 10.3% (from 1,031 to 1,137), and those related to 'Driving too fast for conditions' rose by 26.7% (from 243 to 308).
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 were similar year-over-year, with the majority of incidents in both periods occurring in daylight (8,306 in 2023 vs. 8,205 in 2022) and on dry road surfaces (8,680 in 2023 vs. 9,431 in 2022). Notably, crashes on wet road surfaces increased from 1,655 in September 2022 to 2,856 in September 2023. This corresponded with a rise in crashes where rain was a factor, which increased from 800 to 1,434.
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 most common vehicle makes involved in crashes were consistent year-over-year, with Toyota, Honda, and Ford ranking as the top three in both September 2023 and September 2022. The number of vehicles from each of these top makes saw a slight increase. Analysis of persons involved in crashes shows a similar age distribution across both periods, with the 26-34 age group representing the largest cohort in both September 2023 (4,529 persons) and September 2022 (4,438 persons).
Top Vehicle Makes (21,930 vehicles)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-09-01 to 2023-09-30 · Vehicle unit records
3,049 persons with unknown or unrecorded age excluded from age chart.
Sex Distribution (24,381 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
In September 2023, the highest number of crashes occurred in 30 mph zones (3,228 crashes), followed by 25 mph zones (2,393). This is consistent with September 2022, where 30 mph zones also saw the most crashes (2,945). Fatal crashes were most frequent in 30 mph zones in 2023, with 10 fatalities, an increase from 8 in the prior year. In 2023, five fatal crashes occurred in 65 mph zones, up from one in the same period of 2022.
Fatal crashes by zone: 15 mph: 1 of 163 (0.613%) · 20 mph: 1 of 363 (0.275%) · 25 mph: 4 of 2,393 (0.167%) · 30 mph: 10 of 3,228 (0.31%) · 35 mph: 4 of 1,538 (0.26%) · 45 mph: 1 of 410 (0.244%) · 50 mph: 1 of 260 (0.385%) · 60 mph: 2 of 39 (5.128%) · 65 mph: 5 of 733 (0.682%)
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: massachusetts, MA
- Total crash records analyzed: 11,737
- Total persons involved: 27,833
- Total vehicles involved: 21,930
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). "massachusetts, 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/statewide/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