Trucking Technology as Crash Evidence

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 tells a different part of the story, 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 proves whether the driver was within legal hours-of-service limits at the time of the wreck. Federal regulations only require carriers to retain ELD data for six months, so a preservation letter has to go out before that window closes.

Event Data Recorders: The Truck’s Black Box

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 collision itself. This data allows an accident reconstruction expert 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. EDR data can be overwritten or deleted in as little as 30 days, which is why a preservation letter needs to be sent immediately after a serious crash, before anyone touches the truck.

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, but 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.

What Route Deviation Can Prove

GPS data shows more than where a truck was. It 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.

Sam Aguiar Injury Lawyers sends preservation letters immediately after every serious truck accident case to secure electronic logging device data, event data recorder data, dashcam footage, and telematics records before any of it can be overwritten or destroyed.