Crash Locations Map
About "Crashes in DC"
Crashes in DC is the publicly-available, mapped locations of the Metropolitan Police Department's (MPD) reported crash records. DDOT processes new crash reports each night and creates a mapped point for each crash, provided the MPD has sufficient location info (good quality latitude/longitude coordinates and/or address information).
The purpose of Crashes in DC is to provide crash location data (within 24 hours) to users interested in exploring spatial patterns and creating maps in support of safety analysis. While it is a great resource, users should understand that these data do contain significant gaps and quality issues. Below, DDOT has attempted to highlight the issues we are aware of; we encourage you to read carefully and contact us if you have any questions.
For more information about "Crashes In DC", see below.
Is "Crashes in DC" 100% complete and accurate?
Not all Crashes are Mapped
There are a few reasons for this:
- Poor X/Y Coordinate Data. When DDOT geocodes the crash data, we first attempt to create a point via the XY coordinates provided. by MPD There are some cases where the MPD crash data do not contain accurate or realistic geographic coordinates. In these cases, we will attempt to use the address information to geocode a crash point. THIS IS PRIMARILY AN ISSUE WITH PRE-2016 DATA
- Poor Address or Roadway Information. There may also be cases where ambiguous address or roadway information has been stored for the crash location.
In either case, when DDOT does not have sufficiently high-quality location data, we are unable to map the location of the MPD crash record. Consequently, there will not be a point/record in the Crashes in DC data.
We have notified MPD about this data quality issue and have found that the quality of location data has significantly improved since 2016 (the first year after the RMS Migration)
Summarizing "Crashes in DC" Will Not Match MPD's Reported Crash Statistics
Again, this is expected. Below are a few example scenarios that highlight some known issues.
- Changing conditions, but no subsequent update to the database record. A police officer from a district may report to the scene of a crash and complete the crash report (PD-10 form), and decide the injuries look severe enough to call in the MPD Major Crash Unit (MCU) to do an in-depth investigation. At that time, the injuries may not be fatal. The report is completed and the crash report is provided to DDOT. Subsequently, data and is published to open data. Later, a victim’s condition may worsen. MPD’s Major Crash Unit conducts the investigation, but the original report from the scene, PD-10, is simply kept as the original report on the crash within the investigation files. The crash record is not updated to reflect the fatality.
- Delayed reporting. Another variation of this scenario is that the MCU is not notified of a crash until days after it occurred, because the responding officer did not observe severe injuries. Sometimes severe injuries aren’t immediately apparent and a victim may die in the hospital days later.
- Data entry error. In general, the computerized PD-10 form is based on the on-scene notes of the reporting officer, and the transfer of that information to the database is prone to data entry error. There have been false-positive fatalities in the MPD data feed, and also false negatives for fatalities, where the wrong box was probably checked. The PD-10 is considered the official record of the incident, however, and officers do not correct them; additional investigations would simply add to the records.
- Federal crash reports are never in MPD crash data. Any crashes that occur in the District on Federal Lands are investigated by the US Park Police or other agencies, and are not recorded in the MPD crash data. Both DDOT and MPD track these fatalities separately.
Background on the 2015 RMS Migration
In August of 2015, MPD migrated to a completely new records management system (or RMS). The differences between the old system and the new RMS were significant and a data migration was performed by MPD at this time to transfer old/legacy crash data into the new system. Unfortunately, the migration of these data was not completely accurate or complete. Because the crash data are so critical to Vision Zero, our team has performed a comparative analysis of the current and legacy MPD crash databases. Over a two month period, the DDOT IT team and the Traffic Records Coordinating Committee (TRCC) staff painstakingly evaluated every single table and attribute relevant to crash data and its adherence to the latest MMUCC standard.
TRCC staff discovered several hundred instances of critical crash data which were either omitted during the RMS migration process, improperly translated, or both. We endeavored to identify these problems and then create a detailed 'crosswalk' guide on how the data should have been migrated to best reflect the true nature of the crash events and also to adhere to the appropriate standard (MMUCC).
It is our desire for MPD to reprocess/re-migrate the legacy crash records according to our cross-walk recommendation guide. Thiswill provide a better representation of the original (pre-August 2015) crash data.
This Migration Crosswalk table is included as an attachment at the bottom of this page.
Location Fields Used in Crash Data
The OCTO-supplied latitude of the address location, which is supplied by the MAR.
The OCTO-supplied longitude of the address location, which is supplied by the MAR.
The OCTO-supplied X Coordinates (Maryland State Plane Meters) of the address location, which is supplied by the MAR.
The OCTO-supplied Y Coordinates (Maryland State Plane Meters) of the address location, which is supplied by the MAR.
The MPD-supplied latitude of the crash location. The reporting officer interactively selects the crash location on a web map. This is the Y-coordinate for that location.
The MPD-supplied longitude of the crash location. The reporting officer interactively selects the crash location on a web map. This is the X-coordinate for that location.
The MPD-supplied (Crime Table) MAR-based X Coordinates (Maryland State Plane Meters) of the crash location.
The MPD-supplied (Crime Table) MAR-based Y Coordinates (Maryland State Plane Meters) of the crash location.
Understanding Injury Types
Crashes in DC provides some summary statistics on the types of injuries which occurred within the crash. Below is a listing of the type of injury category and what it is comprised of.
|Injury Type||MPD's PD-10 Injury Description|
|Fatal Injuries||Injury type = 'Fatal' or DOD (Date of death) is not null|
|Major Injuries||Other Major Injury|
|Possible Internal Injury|
|Apparent Broken Bones|
|Loss Of Teeth|
|Apparent Minor Injury|
Other Frequently Asked Questions
What if I need more detail on a crash?
Since "Crashes in DC" is only meant to be a first-glance dataset for mapping and safety analysis, it does not contain all of the relevant information about a crash. If you need to obtain additional detail about a given crash, you must submit a request via a MPD Public Documents Request.
Who do I contact about these data?
Questions on the contents of these layers should be emailed to Metropolitan Police Department or the DDOT Traffic Safety Division. Questions regarding access and viewing the data in Open Data DC can be sent to @OpenDataDC
In Crashes in DC dataset, what does 'Speeding_Involved' Indicate?
This is actually the count of vehicles involved in the crash which were speeding. Whether or not these drivers were actually cited for speeding is not known.
Are fatalities accurately reflected in the data?
Although we attempt to provide accurate data as far as possible, the fatalities data in the open data are likely to show fewer traffic deaths than actually occurred. This is because the crash data are preliminary and are intended for informational purposes. The database records reflect the best information available when the police report is filed and are not updated to reflect a change in condition. For example, a MPD officer may report a crash that meets the criteria for a major injury (see above) but the injuries may not yet be fatal. The record is published to open data, which is not updated later if the person succumbs to his/her injuries.
For more accurate, up-to-date counts of fatalities data, please visit the Metropolitan Police Department's website at https://mpdc.dc.gov/page/traffic-fatalities. To view information about mode, location, and date, please visit the Vision Zero website at https://www.dcvisionzero.com/maps-data. If you need to obtain additional detail about a given crash, you must submit a request via a MPD Public Documents Request.
|Microsoft Excel Spreadsheet Data Mapping_Final.xlsx||Sep 18, 2018 by James Graham|
|PDF File Crash Data New Assets - Addition.pdf||Aug 02, 2019 by James Graham|
|PDF File Legacy System - Data Mapping.pdf||Aug 02, 2019 by James Graham|
|PDF File Crash Data Attributes_NewElementsEditChecks.pdf||Aug 02, 2019 by James Graham|
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