The part that catches people off guard is that an electronic logging device does not just track miles or location. It is a tamper-resistant device tied to a commercial truck's engine that automatically records driving time, engine hours, vehicle movement, and other data used to monitor a driver's compliance with hours-of-service rules.

An electronic logging device, often called an ELD, replaced many paper logbooks for interstate commercial drivers under the Federal Motor Carrier Safety Administration's ELD rule, codified in 49 C.F.R. Part 395 and fully phased in by 2019. That matters because the data can show whether a driver was on the road too long, took required breaks, or may have been pressured by a carrier to keep driving. It can also reveal gaps between what a driver says happened and what the truck's records show.

After a crash, ELD data can become key evidence in an injury claim, especially when fatigue, speeding, or poor supervision may be involved. But this information is not always kept forever, and companies may control access to it. A prompt spoliation letter or preservation request may be needed to protect ELD records before they are overwritten or deleted. In a serious Oklahoma truck crash, including one that leads to treatment at OU Medical Center in Oklahoma City, ELD data may support claims of negligence, negligence per se, or wrongful death against the driver, motor carrier, or both.