WGK Personal Injury Lawyers | November 12, 2025 | Car Accidents

What-Is-a-Black-Box-and-Does-My-Car-Have-One

A car’s black box is an event data recorder, a device that saves a few seconds of driving data around a crash so it can be read afterward.1 It isn’t the flight recorder you’re picturing from an airplane. Yours holds seconds, not hours, and it doesn’t record audio or video.1

That short recording can become car accident evidence, and it can cut either way. This guide covers what the recorder captures, whether your car has one, who owns the data, and how it gets used in a Maryland car accident claim. Call (410) 837-2144 for a free case review.

What We Mean by a Car’s “Black Box”

In a vehicle, the device people call a black box is officially an event data recorder, or EDR.

Federal regulation defines it as a device or function that records the vehicle’s dynamic time-series data just before or during a crash event, intended for retrieval after the crash.1

Two parts of that definition matter for your claim. The recorder captures a short window around the impact, and it’s built to be read later.

The same definition draws a line people assume runs the other way: event data does not include audio or video.1

So the recorder isn’t listening to your conversations and isn’t filming the road. Video is separate evidence, coming from dash-cam footage in your vehicle or from the other driver’s vehicle.

How Does the Black Box Work?

The recorder ties into your car’s computer system, typically through the airbag control module.2 It doesn’t run a tape all day.

It saves nothing while you drive normally. The statement the regulation requires in your owner’s manual says it plainly: no data are recorded by the EDR under normal driving conditions, and no personal data such as name, gender, age, or crash location are recorded. The same statement adds that law enforcement and others “could combine the EDR data with the type of personally identifying data routinely acquired during a crash investigation.”3

When a crash starts, the system fixes an instant that it calls time zero and measures backward from there.4 Time zero is set by things like the restraint control algorithm activating or a non-reversible restraint deploying, not by the moment you remember.4

What the recorder captures

The required data is specific. Federal regulation requires the recorder to log, among other things, the change in the vehicle’s speed during the crash (delta-V), indicated vehicle speed, accelerator pedal position, whether the service brake was on, the driver’s safety belt status, and the time it took the frontal airbag to deploy.5

So: how hard the impact was, how fast you were going, how hard you pressed the gas pedal, whether the brake was on, whether your belt was buckled, and when the airbag fired.

How many seconds it keeps

Five seconds, for most cars on the road today. The recorder must capture the 5 seconds before a crash, sampled twice a second.6 That’s ten readings.

Not a movie of the crash, and not the minute before it.

A longer window is coming. Federal rules extend the recording period from 5 seconds of pre-crash data at 2 Hz to 20 seconds of pre-crash data at 10 Hz, which is ten readings a second.7 The change phases in at 25 percent of each manufacturer’s production from September 2028, 50 percent from September 2029, and 75 percent from September 2030.6

NHTSA has been candid about the shorter window in its own research. Its duration study says most EDRs record only up to 5 seconds of pre-crash data, which is insufficient to determine crash or pre-crash actions in some cases.8

The same report is honest about the other side. It says the analysis can’t show how much pre-crash data is needed to capture crash causation.8

If the car lost power

People ask this once the car has been towed and the battery is disconnected. The recorder writes to non-volatile memory, and the regulation says data recorded there is retained after loss of power and can be retrieved with EDR data extraction tools and methods.4

Does My Car Have One?

Almost certainly, if your car is recent. NHTSA’s internal analysis estimates that 99.5 percent of model year 2021 passenger cars and other vehicles with a gross vehicle weight rating of 8,500 pounds or less are equipped with part 563-compliant EDRs.9

Federal law does not require one, though, and that trips up a lot of what you’ll read online. The federal standard applies to light vehicles manufactured on or after September 1, 2012, if they are equipped with an event data recorder.10

NHTSA says the same thing about its own rule. Part 563 does not mandate EDRs on vehicles, but is instead an “if equipped” standard that applies only to light vehicles required to have frontal airbags.11

Both things are true at once. There’s no mandate, and the model year NHTSA measured has a 99.5 percent equipment rate.

The vehicle classes the standard covers are passenger cars, multipurpose passenger vehicles, trucks, and buses within those weight limits, so it doesn’t reach motorcycles.10

How to check your own car

To check your own car, read the owner’s manual. Manufacturers must include the recorder statement there, making the manual the only place you can look without special equipment.3

Who Owns the Data in Your Car

You do. Under federal law, any data retained by an event data recorder, regardless of when the motor vehicle in which it is installed was manufactured, belongs to the owner, or, in the case of a leased vehicle, the lessee.12

That middle clause matters: ownership doesn’t depend on the model year, so it covers a car built long before the federal recorder standard took effect.12

Who else can reach it

Ownership isn’t an absolute veto, though. The same law says the data may not be accessed by anyone other than an owner or lessee unless one of five conditions is met.12 Two of those matter in a crash claim: authority from a court, and consent from the owner or lessee.12

Consent is the one to watch, because of how broadly it’s written. It counts when an owner or a lessee provides written, electronic, or recorded audio consent.12

So you can give consent on a recorded call, not just on a form you sign. If an insurance company has already asked for access to your car or its data, get advice before you answer. Call (410) 837-2144 for a free case review.

When the Data Survives and When It Gets Written Over

Whether the airbags went off determines which rule applies.

If a frontal airbag deployed, that record is protected. The memory for the airbag deployment event must be locked to prevent any future overwriting of the data.13

If no airbag deployed, the record is exposed. If no empty memory buffer is available, a manufacturer may overwrite previous event data that did not deploy an airbag with the current event data, or not record the current event data.13

That’s the real reason to move quickly after a minor collision, and it beats the vague warning that data “gets erased.” A later event can take your only recording with it.

Why a Single Data Point Matters More in Maryland

Maryland follows pure contributory negligence. A person who fails to use ordinary care for their own safety and contributes to their own injury is barred from all recovery.14

Our explainer on how fault is decided covers the rule and what defeats it. The point here is narrower: a recorded speed, or a brake that was never pressed, is a harder fact in Maryland than in a state that splits fault by percentage.

What the recorder cannot tell you

The recorder doesn’t settle the question by itself, and nobody at the agency claims it does. NHTSA describes what the longer window will buy this way: actions such as running a stop sign or red light could be captured in full and included in crash reconstruction when supplemented with roadway and traffic control information.15

Read the condition at the end. The recorder doesn’t know the light was red. Someone has to pair the numbers with the intersection, the signal timing, and the rest of the evidence in an injury case.

In the rulemaking record, the National Transportation Safety Board said fully understanding crashes involving vehicles with driver-assistance systems would require more pre-crash data than Part 563 currently requires.16 That’s the honest limit on any claim that the recorder witnessed everything.

Getting the Data, and the Records Around It

Someone has to get it, and the download is a specialist job.

The retrieval tool

A tool has to exist, by federal rule. Each manufacturer of a vehicle equipped with an EDR must ensure a tool is commercially available to access and retrieve the required data no later than 90 days after the first sale of the vehicle.17

Reading the download is a second step. It takes the extraction tools and methods the regulation describes,4 plus a crash reconstruction expert who can explain what the numbers mean.

Preserving what exists

We send preservation letters to businesses, state and local governments, and federal buildings, including FOIA requests, and we send a private investigator out for footage that proves liability and shows how hard the impact was. Once a lawsuit is filed, we can subpoena cell phone records, and discovery can reveal phone usage before and after the accident.

For the other driver’s recorder, the routes are the two of the statute’s five conditions that come up in a crash claim: their consent, or authority from a court.12 That second route is why discovery matters, and why the timing of a lawsuit isn’t only about the filing deadline.

The crash report

The police crash report is a separate piece of evidence, and usually the first one to request. If the Maryland State Police investigated the crash, wait at least 10 days before requesting the report so they can process it.18

Requests go to a barrack, by mail, or to the Central Records Division, and the motor vehicle report form carries a $4.00 non-refundable document search fee.18 If the Baltimore Police Department or another local agency investigated the crash, request the report from that agency instead.

Tractor-Trailers Are a Different Question

The federal recorder standard stops at a gross vehicle weight rating of 8,500 pounds, so a tractor-trailer sits outside it entirely.10

On the commercial side, federal rules require carriers to keep driving-time records, but only for a limited time. A motor carrier must keep each driver’s hours-of-service records and supporting documents for at least 6 months.19

Carriers must also maintain an accident register for 3 years after each accident, listing the date, location, driver’s name, injuries and fatalities, and any hazardous material release.20

On commercial vehicles, the evidence can also include engine control module data showing speed and braking, along with dash cams and side-view and rear cameras.

The commercial version of this question belongs on its own page. Start with Maryland truck accident claims if a commercial vehicle hit you.

What This Means for Your Case

The gap between the outer filing deadline and the real evidence window is the whole point of this page.

The statute of limitations

In Maryland, a civil action generally must be filed within three years from the date it accrues, unless another law sets a different deadline.21

Three years is the outer limit, not the working one. Claims against a Maryland local government entity require written notice within 1 year of the injury, and claims against the State require a written claim to the Treasurer or a designee, also within 1 year.22

Now put those against the shorter deadlines on this page. A record from an accident in which the airbag did not deploy (a non-deployment record) can be overwritten by a later event.13 A carrier’s duty-status records have a 6-month floor.19 None of that waits for year three.

What to do now

Four things are worth doing while the records still exist.

  1. Read your owner’s manual. The recorder statement is printed there, and it tells you what your specific vehicle captures.3
  2. Don’t give anyone access to your car or its data without advice. Consent can be written, electronic, or on a recorded call.12
  3. Say so if the airbags did not deploy. That’s the case where the recording sits in a buffer and a later event can overwrite it.13
  4. Get a preservation request out early. The vehicle, nearby video, and a commercial driver’s records all run on clocks shorter than the filing deadline.

A personal injury attorney can do the last three for you. The first one takes five minutes in your glovebox.

Frequently Asked Questions

Does my car have a black box?

Almost certainly, if it’s a recent light vehicle; NHTSA’s internal analysis estimates 99.5 percent of model year 2021 passenger cars and other light vehicles are equipped with Part 563-compliant recorders.9 To confirm yours, read the owner’s manual, where manufacturers must print a statement about the recorder.3 The federal standard reaches vehicles manufactured on or after September 1, 2012, and only if they’re equipped.10

What does a car’s black box actually record?

Your speed, how far the accelerator was pressed, whether the brake was on, whether the driver’s belt was buckled, and when the airbag fired.5 The limits matter just as much. The data doesn’t include audio or video,1 no crash location is recorded, and nothing at all is recorded under normal driving.3

How many seconds before a crash does a black box record?

Five seconds, sampled twice a second, for vehicles manufactured before September 2031.6 That’s ten readings. A 20-second window sampled ten times a second is phasing in, at 25 percent of each manufacturer’s production from September 2028, 50 percent from September 2029, and 75 percent from September 2030.6 The car you’re driving today is on the five-second rule.

Who owns the data in my car’s black box?

You do. Under federal law, the recorder data is the property of the vehicle’s owner, or the lessee of a leased vehicle, regardless of when the vehicle was manufactured.12 Someone else can access it only under one of five conditions, and the two that come up in a crash claim are your consent and a court order.12

Can the insurance company use my black box data against me?

Not by simply asking for your car. Access runs through your consent or a court, and consent counts in writing, electronically, or on a recorded call.12 What the data shows carries real weight in Maryland, where a person who contributes to their own injury is barred from all recovery.14 Our page on how fault is decided covers that rule.

Can black box data be erased or overwritten after a crash?

It depends on the airbags. If a frontal airbag deployed, that memory must be locked against any future overwriting.13 If no airbag deployed, the manufacturer may overwrite that record with a later event, or not record the later event at all.13 Data in non-volatile memory does survive a loss of power, so a written preservation request early is the practical answer.4

How do I get the black box data from the other driver’s car?

Not directly, because that data belongs to that vehicle’s owner or lessee.12 Access comes through their consent or a court order.12 The download itself needs the retrieval tool the manufacturer is required to make commercially available, plus access to the vehicle.17 Reading the result takes a crash reconstruction expert.

Do tractor-trailers have black boxes too?

Usually, but not under the car rule, which stops at 8,500 pounds.10 Most trucks store speed and braking data in their engine control modules and track driving time with electronic logs. Carriers must keep those duty-status records for at least 6 months19 and an accident register for 3 years.20 Learn more about Maryland truck accident claims at Maryland truck accident claims.

Contact Our Maryland Car Accident Lawyers for a Free Consultation

The recorder helps reconstruct what happened, with details like speed, braking, and airbag deployment that can support your version of events. It doesn’t track your movements, and it doesn’t record video. The short burst it holds can still make a real difference in proving who was at fault.

Learning how these recorders work takes an afternoon. Making sure the data still exists when someone asks for it has a deadline.

For more information, contact the Maryland Car Accident law firm of WGK Personal Injury Lawyers to schedule a free initial consultation.

The first conversation is free, and you pay nothing unless we recover compensation for you. Call (410) 837-2144 to start a free case review.

This content is marketing material and is not legal advice. Every case is unique and laws change frequently. Please contact our office to speak with an attorney about your specific situation before making any legal decisions.

Sources

  1. 49 C.F.R. § 563.5 (Definitions), Electronic Code of Federal Regulations, retrieved 2026-09-29. Definition of an event data recorder, including the sentence excluding audio and video data from event data. https://www.ecfr.gov/current/title-49/section-563.5
  2. National Highway Traffic Safety Administration, Event Data Recorders, final rule, 89 FR 102810, 102819, 102821 (Dec. 18, 2024), U.S. Government Publishing Office, retrieved 2026-09-12. NHTSA’s statements that EDR memory is shared with other functions of the airbag control module and that the airbag control unit’s reserve energy allows the EDR to capture and record data; see also the industry comment summarized at 102821 that the EDR function is typically integrated into the ACU or ACM. https://www.govinfo.gov/content/pkg/FR-2024-12-18/html/2024-29862.htm
  3. 49 C.F.R. § 563.11(a) (Information in owner’s manual), Electronic Code of Federal Regulations, retrieved 2026-09-29. The required owner’s manual statement says no data are recorded under normal driving conditions, no personal data such as crash location are recorded, and that law enforcement and others could combine EDR data with personally identifying data from a crash investigation. https://www.ecfr.gov/current/title-49/section-563.11
  4. 49 C.F.R. § 563.5 (Definitions), Electronic Code of Federal Regulations, retrieved 2026-09-29. Definitions of “time zero” and “non-volatile memory,” including that data recorded in non-volatile memory is retained after loss of power and can be retrieved with EDR data extraction tools and methods. https://www.ecfr.gov/current/title-49/section-563.5
  5. 49 CFR 563.7(a), Table I (Data elements required for all vehicles), as printed in National Highway Traffic Safety Administration, Event Data Recorders, final rule, 91 FR 28432 (May 18, 2026), U.S. Government Publishing Office, retrieved 2026-09-12. The required-element rows for indicated vehicle speed, engine throttle or accelerator pedal position, service brake on/off, driver safety belt status, and frontal airbag time to deploy. The recording intervals shown in the table itself are subject to footnote 4 (see footnote 5 below). https://www.govinfo.gov/content/pkg/FR-2026-05-18/html/2026-09849.htm
  6. 49 CFR 563.7(a), Table I, footnote 4, as amended by National Highway Traffic Safety Administration, Event Data Recorders, final rule, 91 FR 28432 (May 18, 2026), effective June 17, 2026, U.S. Government Publishing Office, retrieved 2026-09-12. The -5.0 to 0 sec interval at 2 samples per second is required for vehicles manufactured before September 1, 2031, and the 25, 50, and 75 percent production phase-in beginning September 1, 2028. The footnote carries later dates for small-volume and limited-line manufacturers (September 1, 2032) and for altered or two-or-more-stage vehicles (September 1, 2033). https://www.govinfo.gov/content/pkg/FR-2026-05-18/html/2026-09849.htm
  7. National Highway Traffic Safety Administration, Event Data Recorders, final rule, 89 FR 102810, 102810 (Dec. 18, 2024), U.S. Government Publishing Office, retrieved 2026-09-12. The rule summary extends the recording period for timed data metrics from 5 seconds of pre-crash data at 2 Hz to 20 seconds at 10 Hz. https://www.govinfo.gov/content/pkg/FR-2024-12-18/html/2024-29862.htm
  8. National Highway Traffic Safety Administration, Event Data Recorder Duration Study, Report No. DOT HS 813 082B (Mar. 2022), appendix to a Report to Congress, via the National Transportation Library, U.S. Department of Transportation, retrieved 2026-09-12. The finding that most EDRs only record up to 5 seconds of pre-crash data, and the accompanying limitation that the analysis cannot show what duration beyond 5 seconds is needed to capture crash causation. https://rosap.ntl.bts.gov/view/dot/60878
  9. National Highway Traffic Safety Administration, Event Data Recorders, final rule, 89 FR 102810, 102811 (Dec. 18, 2024), U.S. Government Publishing Office, retrieved 2026-09-12. NHTSA’s internal-analysis estimate that 99.5 percent of model year 2021 light vehicles are equipped with part 563 compliant EDRs. https://www.govinfo.gov/content/pkg/FR-2024-12-18/html/2024-29862.htm
  10. 49 CFR 563.3 (Application), Code of Federal Regulations, Title 49, Volume 6, 2025 annual edition, U.S. Government Publishing Office, retrieved 2026-09-12. The September 1, 2012 manufacture date, the “if they are equipped with an event data recorder” condition, the covered vehicle classes (passenger cars, multipurpose passenger vehicles, trucks and buses), and the 8,500 pound gross vehicle weight rating and 5,500 pound unloaded weight ceilings. https://www.govinfo.gov/content/pkg/CFR-2025-title49-vol6/xml/CFR-2025-title49-vol6-part563.xml
  11. National Highway Traffic Safety Administration, Event Data Recorders, final rule, 89 FR 102810, 102810 (Dec. 18, 2024), U.S. Government Publishing Office, retrieved 2026-09-12. The agency’s statement that part 563 does not mandate EDRs and is instead an “if equipped” standard applying only to light vehicles required to have frontal air bags. https://www.govinfo.gov/content/pkg/FR-2024-12-18/html/2024-29862.htm
  12. 49 U.S.C. 30101 note, Limitations on Data Retrieval From Vehicle Event Data Recorders (Driver Privacy Act of 2015, Pub. L. 114-94, sec. 24302), Office of the Law Revision Counsel, retrieved 2026-09-12. Subsection (a), making recorder data the property of the owner or lessee regardless of when the vehicle was manufactured; subsection (b), barring access by anyone else except under five listed conditions; and subsection (b)(2), the written, electronic or recorded audio consent exception. The first listed condition is a court or other judicial or administrative authority having jurisdiction. https://uscode.house.gov/view.xhtml?req=granuleid%3AUSC-prelim-title49-section30101&num=0&edition=prelim
  13. 49 CFR 563.9 (Data capture and format requirements), Code of Federal Regulations, Title 49, Volume 6, 2025 annual edition, U.S. Government Publishing Office, retrieved 2026-09-12. The requirement that the memory for an air bag deployment event be locked against future overwriting, and the allowance permitting a manufacturer to overwrite previous non-deployment event data with a current event, or to not record the current event, where no empty buffer is available. https://www.govinfo.gov/content/pkg/CFR-2025-title49-vol6/xml/CFR-2025-title49-vol6-part563.xml
  14. Coleman v. Soccer Association of Columbia (2013); Harrison v. Montgomery County Board of Education (1983). https://www.mdcourts.gov/data/opinions/coa/2013/9a12.pdf
  15. National Highway Traffic Safety Administration, Event Data Recorders, final rule, 89 FR 102810, 102811 (Dec. 18, 2024), U.S. Government Publishing Office, retrieved 2026-09-12. The agency’s explanation that actions such as running a stop sign or red light could be captured in full and included in crash reconstruction when supplemented with roadway and traffic control information. https://www.govinfo.gov/content/pkg/FR-2024-12-18/html/2024-29862.htm
  16. National Highway Traffic Safety Administration, Event Data Recorders, final rule, 89 FR 102810, 102816 (Dec. 18, 2024), U.S. Government Publishing Office, retrieved 2026-09-12. NHTSA’s summary of the National Transportation Safety Board’s comment that a complete understanding of crashes involving vehicles with advanced driver assistance systems would necessitate more pre-crash data than part 563 currently requires. This is the agency’s characterization of a comment in the rulemaking record, not an NTSB publication. https://www.govinfo.gov/content/pkg/FR-2024-12-18/html/2024-29862.htm
  17. 49 CFR 563.12 (Data retrieval tools), Code of Federal Regulations, Title 49, Volume 6, 2025 annual edition, U.S. Government Publishing Office, retrieved 2026-09-12. The requirement that each manufacturer ensure a commercially available tool capable of accessing and retrieving the required EDR data, no later than 90 days after the first sale of the vehicle for purposes other than resale. https://www.govinfo.gov/content/pkg/CFR-2025-title49-vol6/xml/CFR-2025-title49-vol6-part563.xml
  18. Maryland Department of State Police, Request Police Reports, retrieved 2026-09-12. The instruction to wait at least 10 days after the accident before requesting a report, the $4.00 non-refundable document search fee payable by check or money order for the motor vehicle report form, the barrack, mail and Central Records Division request routes, and the referral of Baltimore City crash requests to the Baltimore Police Department. Scope: crashes investigated by the Maryland State Police. https://mdsp.maryland.gov/community-services/request-police-reports
  19. 49 CFR 395.8(k)(1) (Driver’s record of duty status), Code of Federal Regulations, Title 49, Volume 5, 2025 annual edition, U.S. Government Publishing Office, retrieved 2026-09-12. The requirement that a motor carrier retain records of duty status and supporting documents for each driver for not less than 6 months from the date of receipt. Applies to interstate motor carriers. https://www.govinfo.gov/content/pkg/CFR-2025-title49-vol5/xml/CFR-2025-title49-vol5-part395.xml
  20. 49 CFR 390.15(b) (Assistance in investigations and special studies), Code of Federal Regulations, Title 49, Volume 5, 2024 annual edition, U.S. Government Publishing Office, retrieved 2026-09-12. The requirement that motor carriers maintain an accident register for 3 years after the date of each accident, and the register contents (date, location, driver name, injuries, fatalities, hazardous material release, and copies of accident reports required by State or other governmental entities or insurers). https://www.govinfo.gov/content/pkg/CFR-2024-title49-vol5/xml/CFR-2024-title49-vol5-sec390-15.xml
  21. Md. Code, Cts. & Jud. Proc. 5-101 (statute of limitations), current statute text, Maryland General Assembly, retrieved 2026-09-12. A civil action at law shall be filed within three years from the date it accrues unless another provision of the Code provides a different period. Known exceptions: other Code provisions set different periods, and section 5-201 tolls for minors and incompetents. https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gcj&section=5-101
  22. Md. Code, Cts. & Jud. Proc. 5-304 (written notice of a claim against a Maryland local government entity within 1 year of the injury), https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gcj&section=5-304, and Md. Code, State Gov’t 12-106 (written claim to the State Treasurer or a designee within 1 year of the injury), https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gsg&section=12-106; current statute text, Maryland General Assembly, both retrieved 2026-09-12.