ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · DEDHAM, MA · 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/dedham/2023-annual-report
Yearly Traffic Safety Analysis
473 CRASHES IN
DEDHAM, MA
2023
In 2023, Dedham recorded 473 total traffic crashes, an 8.5% increase from the 436 crashes reported in 2022. While total crashes and injuries rose, the number of fatalities decreased from 5 in 2022 to 2 in 2023. A notable shift was the increase in crashes on wet roads, which grew from 60 incidents in the prior year to 92 in the current year.
473
▲ 8.5%was 436
Total Crash Events
2
▼ -60.0%was 5
Persons Killed
171
▲ 10.3%was 155
Persons Injured
23
▼ -8.0%was 25
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. 14 crashes with unreported severity are not shown in the severity breakdown.
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Overall traffic collisions in Dedham trended upward, with total crashes increasing by 8.5% from 436 in 2022 to 473 in 2023. The number of people injured in these crashes also rose by 10.3%, from 155 to 171. Despite the rise in crashes and injuries, the number of fatalities saw a significant decrease, falling from 5 in the prior year to 2 in the current year.
23
Hit-and-Run Crashes — 2023
▼ -8.0% vs prior (25)
The number of hit-and-run incidents in Dedham saw a slight decrease year-over-year. In 2023, there were 23 reported hit-and-run crashes, down from 25 in 2022. This corresponds to a decrease in the hit-and-run rate, which fell from 5.7% of all crashes in 2022 to 4.9% in 2023.
Vulnerable Road User Casualties
0
Pedestrians Killed
0
Cyclists Killed
2
Motorists Killed
0
Other Killed
3
Pedestrians Injured
3
Cyclists Injured
164
Motorists Injured
1
Other Injured
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The temporal patterns of crashes showed some shifts between the two periods. In 2023, the peak day for crashes was Thursday with 82 incidents, a change from 2022 when Tuesday and Friday were the peak days with 71 crashes each. However, the afternoon commute remained the most hazardous time, with the 5 PM hour being the peak for crashes in both 2023 (51 crashes) and 2022 (42 crashes).
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Crash date field aggregated by weekday
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
Crash severity outcomes improved regarding fatalities but worsened for injuries. The number of fatal crashes dropped from 5 in 2022 to 2 in 2023, and the fatal crash rate decreased from 1.15% to 0.42% of all crashes. Conversely, the share of crashes resulting in some form of injury (serious, minor, or possible) increased from 24.8% in 2022 to 28.1% in 2023, with minor and possible injury crashes both seeing increases in their total counts.
Outcome by Severity (Crash Events)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · KABCO injury classification scale
Severity Distribution (Crash Events)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Most severe injury per crash record
Top Contributing Factors
The leading contributing factors for crashes remained consistent year-over-year, with 'No improper driving,' 'Followed too closely,' and 'Inattention' being the top three reported factors in both periods. The count of crashes attributed to 'Followed too closely' increased by 13.2%, from 53 to 60 incidents. In contrast, crashes related to speed saw a notable decline, with those attributed to 'Driving too fast for conditions' decreasing in count by 55% from 20 to 9 incidents.
Officer-Reported Primary Contributing Cause
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
The majority of crashes in both years occurred in clear weather and daylight on dry roads, with the proportions remaining stable. In 2023, 78.4% of crashes occurred on dry roads, compared to 79.6% in 2022. However, there was a notable increase in crashes occurring on wet roads, with the count rising from 60 in 2022 to 92 in 2023. Crashes during daylight hours accounted for 64.5% of incidents in 2023, a slight decrease from 66.5% in the prior year.
Weather
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Weather condition at time of crash
Lighting
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Lighting condition field
Road Surface
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Road surface condition field
Vehicles & Demographics
The top vehicle makes involved in crashes remained largely unchanged, with Toyota (182 vehicles) and Honda (135 vehicles) holding the top two spots in 2023, both increasing in count from the prior year. The age distribution of persons involved in crashes showed a shift, with the 26-34 age group seeing an increase from 175 to 204 individuals. Conversely, the 35-44 age group saw a decrease in involvement from 199 to 170 individuals.
Top Vehicle Makes (891 vehicles)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Vehicle unit records
68 persons with unknown or unrecorded age excluded from age chart.
Sex Distribution (977 persons with recorded sex)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · Person-level records linked to crash events
Speed Limit Zones
Crashes in the 55 mph speed zone were the most frequent in both years, increasing slightly from 121 to 126 incidents. There was a notable decrease in crashes occurring in lower speed zones, with incidents in 30 mph zones falling from 89 to 71 and those in 25 mph zones dropping from 58 to 27. In 2023, the two fatal crashes occurred in 35 mph and 40 mph zones, whereas in 2022, five fatal crashes were spread across 35, 40, 45, and 55 mph zones.
Fatal crashes by zone: 35 mph: 1 of 29 (3.448%) · 40 mph: 1 of 14 (7.143%)
Source: Massachusetts Crash Data (MassDOT CDV) · Arcgis_yearly Open Data · 2023-01-01 to 2023-12-31 · 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: 2023-01-01 through 2023-12-31
- Report generated: June 21, 2026
Data Coverage
- Reporting period: 2023-01-01 through 2023-12-31 (365 days)
- Geographic scope: DEDHAM, MA
- Total crash records analyzed: 473
- Total persons involved: 1,057
- Total vehicles involved: 891
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). "DEDHAM, MA Crash Intelligence Report: 2023." Published June 21, 2026. Reporting period: 2023-01-01 to 2023-12-31. Data source: Massachusetts Crash Data (MassDOT CDV), Arcgis_yearly Open Data. Available at: https://thatcarhitme.com/crash-data/massachusetts/dedham/2023-annual-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: 2023-01-01 – 2023-12-31
Generated: June 21, 2026 · All rights reserved