ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · MONTGOMERY, MD · DECEMBER 2021
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/maryland/statewide/december-2021-report
Monthly Traffic Safety Analysis
905 CRASHES IN
MONTGOMERY, MD
DECEMBER 2021
In December 2021, Montgomery County recorded 905 total vehicle crashes, a 26.8% increase from the 714 crashes reported in December 2020. This year-over-year comparison shows a significant rise in total crash volume. The most notable shift was this overall increase in collisions, which was also reflected in a rise in total injuries from 225 to 274.
905
▲ 26.8%was 714
Total Crash Events
2
▲ 100.0%was 1
Persons Killed
274
▲ 21.8%was 225
Persons Injured
192
▲ 18.5%was 162
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. 4 crashes with unreported severity are not shown in the severity breakdown.
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Crash trends in Montgomery County show a significant increase in December 2021 compared to the same month in the prior year. Total crashes rose by 26.8% from 714 to 905. This upward trend was also observed in crash outcomes, with total injuries increasing by 21.8% and fatalities doubling from one to two.
192
Hit-and-Run Crashes — December 2021
▲ 18.5% vs prior (162)
The number of hit-and-run incidents increased from 162 in December 2020 to 192 in December 2021, an 18.5% rise in count. However, because total crashes increased at a faster pace, the hit-and-run rate as a proportion of all crashes decreased. The hit-and-run rate fell from 22.7% in the prior year to 21.2% in the current year, indicating that hit-and-runs made up a smaller share of total collisions.
Vulnerable Road User Casualties
0
Pedestrians Killed
0
Cyclists Killed
2
Motorists Killed
0
Other Killed
30
Pedestrians Injured
4
Cyclists Injured
239
Motorists Injured
1
Other Injured
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The temporal patterns of crashes remained consistent between December 2020 and December 2021. Wednesday was the busiest day for crashes in both periods, with counts rising from 126 to 167 year-over-year. The evening commute hour of 5 p.m. also remained the peak time for collisions, with the number of crashes during this hour increasing from 58 to 89. While the timing of these peaks did not shift, the volume of crashes during these periods grew significantly.
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Crash date field aggregated by weekday
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
The severity of crashes saw some shifts between the two periods. The fatal crash rate increased from 0.14% in December 2020 to 0.22% in December 2021. The proportion of crashes involving serious injuries also rose slightly, from 0.8% to 1.2% of all incidents. Meanwhile, the share of crashes resulting in minor or possible injuries decreased slightly, while the proportion of no-injury crashes remained nearly constant at approximately 73%.
Outcome by Severity (Crash Events)
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · KABCO injury classification scale
Severity Distribution (Crash Events)
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Most severe injury per crash record
Top Contributing Factors
The leading environmental factors showed some changes year-over-year. Crashes associated with wet conditions ('N/A, WET') remained a top factor, with a slight increase in count from 59 in December 2020 to 61 in December 2021. However, the count of crashes related to 'RAIN, SNOW, WET' decreased from 34 to 24. A notable change was the absence of 'ICY OR SNOW-COVERED' related factors from the top of the list in 2021, which accounted for a combined 49 crashes under various icy categories in December 2020, suggesting different weather patterns between the two periods.
Officer-Reported Primary Contributing Cause
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
A comparison of road conditions reveals a significant difference between the two periods. In December 2021, 71.4% of crashes occurred on dry roads, a notable increase from 58.5% in December 2020. Consequently, the share of crashes on adverse surfaces like wet, snow, or ice was significantly lower in 2021. Lighting conditions remained proportionally similar, with about half of all crashes in both years occurring during daylight hours.
Weather
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Weather condition at time of crash
Lighting
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Lighting condition field
Road Surface
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Road surface condition field
Vehicles & Demographics
The most common vehicle makes involved in crashes remained consistent year-over-year. In both December 2020 and December 2021, Toyota, Honda, and Ford were the top three makes, respectively. The number of vehicles from these top makes involved in crashes increased, with Toyota seeing a 32% rise from 172 to 227 vehicles, and Ford experiencing a 19% increase from 132 to 157 vehicles. The ranking and prevalence of top vehicle types, led by Passenger Cars, also showed no significant proportional shifts between the two periods.
Top Vehicle Makes (1,579 vehicles)
Source: Montgomery County Crash Reporting (ACRS) · Socrata Open Data · 2021-12-01 to 2021-12-31 · Vehicle unit records
Data Sources & Methodology
Primary Data Source
All crash data in this report is sourced from Montgomery County Crash Reporting (ACRS) (https://data.montgomerycountymd.gov/d/bhju-22kf), accessed programmatically via the Socrata 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: Socrata Open Data API (SoQL queries)
- Dataset URL: https://data.montgomerycountymd.gov/d/bhju-22kf
- Data format: Structured JSON via REST API
- Record types queried: Crash events, person records, and vehicle unit records
- Date filter applied: 2021-12-01 through 2021-12-31
- Report generated: September 9, 2026
Data Coverage
- Reporting period: 2021-12-01 through 2021-12-31 (31 days)
- Geographic scope: montgomery, MD
- Total crash records analyzed: 905
- Total persons involved: 1,617
- Total vehicles involved: 1,579
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). "montgomery, MD Crash Intelligence Report: December 2021." Published September 9, 2026. Reporting period: 2021-12-01 to 2021-12-31. Data source: Montgomery County Crash Reporting (ACRS), Socrata Open Data. Dataset: https://data.montgomerycountymd.gov/d/bhju-22kf. Available at: https://thatcarhitme.com/crash-data/maryland/statewide/december-2021-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: Montgomery County Crash Reporting (ACRS) · Socrata
Period: 2021-12-01 – 2021-12-31
Generated: September 9, 2026 · All rights reserved