Trucking Technology as Crash Evidence

After a semi-truck crash, witnesses disagree, drivers deny fault, and insurance adjusters minimize what happened. The data the truck was already recording when the crash occurred resolves many of those disputes. According to the National Safety Council, 5,472 people died in large-truck crashes in 2023, and 153,452 more were injured, with 70% of those deaths occurring among occupants of other vehicles. The truck involved in a crash was likely recording data for hours, or even days, before impact, and that data is recoverable only if someone preserves it in time.

Four Sources of Digital Evidence on a Modern Truck

A fully equipped modern tractor-trailer can carry four separate sources of digital evidence: an electronic logging device recording hours of service and location, an event data recorder capturing pre-crash vehicle dynamics, a dashcam recording video and audio of the road and cab, and a telematics platform transmitting real-time data to the carrier’s fleet management system. Each source records a different part of the event, and together they create a picture that is difficult to dispute in court.

What Electronic Logging Devices Record

The Federal Motor Carrier Safety Administration required most commercial motor vehicle drivers to switch from paper logbooks to electronic logging devices beginning December 18, 2017, under the authority of 49 CFR Part 395. The rule applies to commercial motor vehicles weighing more than 10,000 pounds whose drivers are required to keep records of duty status.

An ELD connects directly to the truck’s engine and automatically captures GPS location at regular intervals while in motion, engine power and vehicle motion status, miles driven and engine hours, every duty status change, and driver and vehicle identification information. In a crash case, this data shows whether the driver was within legal hours-of-service limits at the time of the crash. Federal regulations require carriers to retain ELD data for only six months, so a preservation letter has to reach the carrier before that window closes.

Event Data Recorder (Black Box) Data

Separate from the ELD, most commercial trucks are equipped with an event data recorder, commonly called the black box. Where the ELD tracks hours and location, the EDR captures the truck’s mechanical behavior in the moments surrounding a crash, including vehicle speed at close intervals, brake application timing and pressure, throttle position, cruise control status at the time of impact, steering wheel angle, and the change in velocity during the crash itself.

This data allows an accident reconstructionist to build a detailed account of what the truck was doing before impact, whether the driver ever applied the brakes, and whether cruise control was still engaged. What is recorded and how long it remains available depend on the device, configuration, subsequent events, and handling of the vehicle. No universal 30-day retention window applies, so the system needs to be identified and preservation requested promptly.

Dashcams and Forward-Facing Camera Systems

Major fleet management vendors now deploy AI-powered dashcam systems that record continuously and flag specific driving events for review, typically with both road-facing and driver-facing cameras. These systems capture continuous road-facing video, driver-facing footage that can show drowsiness or phone use, hard braking events, sudden lane changes, and following distance from the vehicle ahead.

Some systems combine this footage with behavioral data and risk scores to build a detailed profile of each driver, a profile that can be subpoenaed to show a pattern of unsafe driving the carrier knew about and failed to address. Dashcam footage is persuasive because a jury can watch what happened. Carriers control that footage, and video can be overwritten in days, sometimes faster than the EDR window.

Fleet Telematics Platforms and GPS Data

Beyond individual device data, most large carriers use enterprise fleet telematics platforms that aggregate everything into a single dashboard, recording real-time GPS position and route history, speed levels and speeding alerts by road segment, hard braking and rapid acceleration events, engine idle time, and driver performance scores. This data connects a driver’s individual behavior to the carrier’s own knowledge. If a carrier’s dashboard was flagging a specific driver for repeated speeding on a route for weeks before a crash, that record can establish that the company knew about the risk and did nothing.

Route Deviation Evidence

GPS data shows whether a driver followed the assigned route, whether unexplained stops occurred, and whether the truck entered an area it had no business being in. GPS logs also provide time-stamped speed data that reconstructs a crash timeline, which investigators cross-reference with posted speed limits and physical evidence at the scene. A route deviation can challenge a driver’s account of events, or reveal that a carrier’s delivery scheduling was unrealistic, creating pressure to speed or skip required rest.

Preservation requests work best when they are tailored to the specific electronic records at risk and directed to each custodian, with follow-up and court relief where needed. A letter alone does not guarantee retention.