What Happens to Truck Data After a Crash
In the hours immediately following a serious commercial vehicle incident, a parallel process begins that has almost nothing to do with the scene itself. The vehicle is generating data when it crashes; it stops generating new data once the engine is off; and the data it has already generated begins, by default, to expire. The post-incident data pipeline — how carriers, insurers, and other parties preserve, access, and ultimately contest that data — is one of the most procedurally specific parts of commercial transportation practice. It is also one of the least well understood outside the safety and risk-management functions that handle it day to day.
Notification and the preservation trigger
The carrier's formal awareness of an incident usually begins with a phone call: from the driver, from law enforcement, or from a dispatcher who has lost contact. Within minutes the call ladders up to the safety director and, for any incident involving injuries, fatalities, or significant property damage, to outside counsel. The moment that escalation begins is, functionally, the moment litigation becomes "reasonably anticipated" for spoliation-doctrine purposes. The duty to preserve electronically stored information attaches at that point. Routine deletion schedules are suspended on the affected vehicle and driver record, and litigation holds are issued internally to the safety, dispatch, and telematics-administration functions.
The legal framework is Federal Rule of Civil Procedure 37(e) and the substantial body of case law applying it to commercial transportation. Routine destruction pursuant to a documented retention policy is generally protected — but only up to the point at which preservation duties attach. Continued operation of a thirty-day deletion schedule on dashcam continuous footage after a fatality, for example, will produce sanctions that range from adverse-inference instructions to (in egregious cases) terminating sanctions.
What gets preserved, in what order
The post-incident preservation sequence is roughly stratified by volatility — the most easily lost data is addressed first.
- ECM data. The engine control module retains a finite number of hard-stop and last-stop event records. Subsequent triggered events can overwrite the data of interest. Best practice is to secure the vehicle and not restart the engine until an ECM download has been performed. In serious-injury and fatality cases the download is typically a joint procedure with representatives of all interested parties present.
- Dashcam footage. Continuous loop footage on local storage will overwrite within days. Triggered event clips are uploaded to the carrier's cloud platform and retained longer, but continuous footage from the period around the incident must be manually preserved to survive.
- Telematics platform data. Detailed event logs on most platforms retain for 90 days or less by default. Carriers issue internal preservation flags that move the relevant vehicle and driver records out of the normal retention rotation.
- ELD records. The on-device data window is short (current 24 hours plus the previous 7 days) but the back-office record is retained for the standard six-month period. After a reportable incident the relevant duty records are flagged for indefinite preservation.
- Driver qualification file, maintenance records, dispatch records, communications logs. Less volatile but subject to ordinary retention schedules that are likewise suspended.
FMCSA accident reporting and MCS-150
Carriers are required to report "recordable" accidents on their accident register and to update accident-related fields on the MCS-150 (motor carrier identification report) at the next biennial filing. The federal definition of a recordable accident is narrow: a fatality, an injury requiring transport from the scene for medical treatment, or disabling damage requiring a vehicle to be towed from the scene. The accident register, maintained under 49 CFR § 390.15, is itself a category of preserved record subject to the data-pipeline discussion above.
The carrier's safety performance data flows into the FMCSA's Safety Measurement System, which feeds the Crash Indicator BASIC and influences inspection prioritization. The Crash Indicator does not at present distinguish between preventable and non-preventable crashes for most purposes, though FMCSA's Crash Preventability Determination Program allows carriers to seek a non-preventability determination on certain crash types.
Spoliation letters and the access process
Parties other than the carrier — typically claimants' representatives in cases involving injuries — generally serve a preservation or spoliation letter within days of an incident. A standard letter identifies the data sources at issue (ECM, ELD, dashcam, telematics, maintenance, dispatch), demands suspension of routine deletion, and frequently includes a request to participate in any vehicle download or inspection. The carrier's counsel responds, the parties negotiate a download protocol, and the actual ECM extraction is conducted as a joint procedure with chain-of-custody documentation.
The same general process governs access to dashcam footage and telematics data, though the mechanics are different because the data sits on the carrier's cloud systems rather than on the vehicle. Production is generally subject to formal discovery requests once litigation is filed, with preservation in the interim. Disputes about what was preserved, when, and by whom are common — see telematics in accident reconstruction for the broader picture of how this data flows into reconstruction work.
The threshold question is no longer whether data exists. It is whether the data that exists has been preserved.
The carrier's internal pipeline
Inside the carrier, post-incident data handling is typically run by a small team: safety director, claims manager, telematics administrator, and outside counsel. Standard operating procedures cover when to dispatch a forensic data download team to the scene, when to tow the vehicle to a secure location rather than allowing on-scene release, how to preserve and image dashcam media, and how to flag the affected vehicle and driver records across the carrier's systems for retention exception. Well-run programs have these procedures documented and rehearsed. Carriers without them tend to discover the gaps the hard way.
The point of the procedure
None of this is about producing a particular outcome in any given case. It is about ensuring that the underlying data — the facts about what the vehicle was doing in the period leading up to the incident — survives the period in which it would otherwise be overwritten. Whether those facts ultimately favor the carrier, the other parties, or neither is not something the preservation process can or should try to control. What the preservation process can control is whether the question gets answered from data or from competing inferences. The post-2010 industry consensus is that data, even when it is unfavorable, is preferable to inference.