Electronic Logging Device Truck Accident Data: What It Shows

An electronic logging device (ELD) truck accident case involves a commercial truck's onboard recorder that automatically tracks a driver's hours, movement, and engine activity, and that data can show whether the driver was fatigued, speeding, or violating federal hours-of-service rules at the time of a crash. This data is often one of the most important pieces of evidence in a truck crash claim, but it is also fragile and controlled by the trucking company, which means it needs to be identified and preserved quickly.

Key takeaways

• ELDs record a truck driver's duty status, driving time, speed, and location automatically, creating a digital trail that can be compared against federal hours-of-service limits.
• Federal law generally requires motor carriers to keep ELD records for only 6 months, so evidence can be lost if no one asks for it in time.
• ELD data can show hours-of-service violations, but it is not the only evidence of fatigue or fault — it works alongside dispatch records, GPS, and maintenance logs.
• A formal evidence preservation request (sometimes called a "spoliation letter") is often needed to stop a carrier from erasing or overwriting data.
• Getting ELD data usually requires legal steps like a subpoena or discovery request if the carrier does not release it voluntarily.

What is an electronic logging device, and why does it matter after a crash?

An electronic logging device is a piece of hardware connected to a commercial truck's engine that automatically records how long and how far the vehicle has been driven. The Federal Motor Carrier Safety Administration (FMCSA) requires most interstate commercial drivers to use ELDs instead of paper logbooks to track compliance with hours-of-service rules, which limit how long a driver can be on the road before resting.

Because the device pulls data directly from the engine, it is generally considered more reliable than handwritten logs, which drivers could previously fill out inaccurately. After a crash, this data can help answer a central question: was the driver legally allowed to be driving at that moment, or had they been on the road too long?

What does ELD data actually record?

ELD data typically captures several categories of information tied to specific times and locations. This generally includes:

• Driving time and total hours on duty
• Duty status changes (on-duty, off-duty, sleeper berth, driving)
• Vehicle speed and movement at various points
• Engine power-up and shutdown events
• Location data at intervals throughout the trip
• Malfunction or diagnostic codes, if the device had technical issues

This information can be cross-checked against the federal hours-of-service limits to see whether a driver exceeded them before the crash.

What federal hours-of-service rules apply to truck drivers?

Federal hours-of-service rules limit how many hours a commercial driver can drive and work before taking required rest, and ELD data is used to enforce these limits. For property-carrying drivers (most tractor-trailers and delivery trucks), the rules generally include:

• 11 hours of driving allowed after 10 consecutive hours off duty
• No driving permitted after the 14th hour on duty following that rest period
• A required 30-minute break after 8 cumulative hours of driving
• A cap of 60 hours on duty in 7 days, or 70 hours in 8 days, depending on the carrier's schedule
• A 34-hour "restart" period that can reset the weekly hour count
• Adverse driving conditions (such as severe weather) can extend the 11-hour and 14-hour limits by up to 2 hours

Passenger-carrying drivers (such as bus drivers) operate under different limits: generally 10 hours of driving after 8 consecutive hours off duty, with no driving allowed after 15 hours on duty. These rules come from 49 CFR Part 395, which is published by the FMCSA and can be reviewed on fmcsa.dot.gov or ecfr.gov.

If ELD data shows a driver exceeded these limits before a crash, it can support a claim that fatigue contributed to the collision. You can use the DOT hours of service calculator to get a general sense of how these limits work, though the actual facts of a case depend on the driver's real logged hours.

How can ELD data help prove fault in a truck accident?

ELD data can help establish fault by showing whether a driver was fatigued, speeding, or otherwise violating safety rules at the time of the crash. For example, if the data shows a driver had been on duty for 15 hours with no required break, that pattern supports an argument that fatigue played a role in the collision.

ELD data is rarely used alone. It is typically combined with other evidence, such as:

• The truck's event data recorder (sometimes called a "black box"), which can show braking and speed at the moment of impact
• Dispatch records and bills of lading, showing scheduling pressure
• Driver qualification files and training records
• Maintenance and inspection logs
• Dashcam or surveillance footage, if available
• The police report from the crash scene (see Truck Accident Police Report: What It Is and How to Get It)

Together, this evidence can build a picture of what happened and why. For a broader view of what to collect after a crash, see the Truck Accident Evidence to Preserve: A Complete Checklist.

Example: how ELD data might reveal a violation

For example, suppose a truck driver's ELD shows they started their shift at 6 a.m. and were still driving at 9 p.m. — 15 hours later — when the crash occurred. That pattern would exceed the 14-hour on-duty limit for property-carrying drivers, and it could indicate the driver falsified a duty status change, was pressured by dispatch to keep driving, or the carrier failed to monitor compliance. This is a simplified example to illustrate the concept, not a description of any real case.

Why does ELD data disappear quickly, and how is it preserved?

ELD data disappears quickly because carriers are generally required to retain these records for only 6 months, and some systems can be overwritten or deleted sooner through normal business practices. This short retention window is one of the most urgent reasons to act fast after a truck crash.

To preserve this evidence, a formal written request — often called a "litigation hold" or "spoliation letter" — is typically sent to the trucking company and its insurer, instructing them to retain all electronic data related to the crash, including:

• ELD/hours-of-service records
• GPS and telematics data
• Event data recorder (black box) downloads
• Dashcam footage
• Internal communications about the crash

If a carrier destroys evidence after receiving such a notice — or after it reasonably should have known litigation was likely — it may face legal consequences for "spoliation of evidence," which can include a court instructing a jury to assume the missing evidence was unfavorable to the carrier.

What if the trucking company won't release the data voluntarily?

If a carrier does not release ELD data voluntarily, it can usually be obtained through formal legal procedures once a claim or lawsuit is underway. This often involves a subpoena (a legal order requiring a person or company to produce documents or testify) or a discovery request during litigation. For more on these processes, see What Is a Subpoena in Truck Accident Cases? and What Is Discovery in Truck Accident Cases? A Plain Guide.

What should you do after a truck accident to protect ELD evidence?

The most important step is to act quickly, since this data can be legally destroyed after the retention period ends. A general checklist looks like this:

For a step-by-step look at official reporting, see How to File a Truck Accident Report: A Step-by-Step Guide.

Does ELD evidence affect how much a claim is worth?

ELD evidence does not set a value for a claim by itself, but it can strengthen an argument about fault, which can affect negotiations and potential damages. Clear evidence of a hours-of-service violation may also support a claim for punitive damages in some states, which are intended to punish particularly reckless conduct rather than simply compensate for losses — see Punitive Damages in Truck Accident Cases: When Are They Allowed? for how that works.

No article or calculator can tell you what a specific case is worth, since that depends on factors like the severity of injuries, medical costs, lost income, liability disputes, and applicable insurance coverage. The truck accident settlement calculator and pain and suffering calculator can offer a general educational estimate based on information you provide, but they are not a substitute for case-specific legal advice.

How is a truck accident claim involving ELD data different from a car accident claim?

Truck accident claims involving ELD data differ from ordinary car accident claims because they involve federal safety regulations, multiple potentially liable parties, and specialized evidence that does not exist in passenger vehicle crashes. A trucking company, not just the driver, may be held responsible if it pressured a driver to violate hours-of-service rules or failed to maintain its ELD system properly. For a fuller comparison, see Truck Accident vs Car Accident Claim: Key Legal Differences.

Minimum insurance requirements also differ for commercial carriers. Interstate for-hire carriers must generally carry at least $750,000 in liability coverage for general freight, $1,000,000 for certain other materials, and $5,000,000 for carriers of certain hazardous materials, under 49 CFR Part 387. See Truck Accident Insurance Minimums: What Coverage Applies for more detail.

What happens after ELD data shows a violation?

If ELD data confirms a violation, it becomes part of the broader evidence record used during negotiation or litigation, not an automatic admission of fault. Trucking insurers and their adjusters often dispute or contextualize this data, so it helps to understand how those conversations typically go — see Dealing with Trucking Insurance Adjusters After a Crash.

A driver found to have violated hours-of-service rules may also face employment consequences, which is a separate issue from the civil claim — see Can a Truck Driver Be Fired for an Accident? and What Happens When a Truck Driver Has an Accident? for background on what typically follows a crash.

If a claim proceeds to a lawsuit, ELD data is usually obtained and reviewed during the discovery phase, and a case may or may not go to trial depending on how the evidence holds up and how both sides negotiate — see Do Semi Truck Accident Cases Go to Trial? and How Do Truck Accident Lawsuits Work? A Step-by-Step Guide for the general process.

What are the filing deadlines for a claim involving ELD evidence?

Filing deadlines, called statutes of limitations, vary significantly by state. Most states generally allow two or three years to file a personal injury claim, a few allow only one year, and some allow longer, but you should never assume you have ample time. Claims against government agencies and wrongful death claims (see Truck Accident Wrongful Death Claim: What Families Need to Know) often have different, sometimes shorter, deadlines and notice requirements.

Because ELD data itself is only retained for about 6 months, the practical deadline to preserve this evidence is often much shorter than the legal deadline to file a lawsuit. Check your state's specific rules using the truck accident deadlines and fault rules by state page or the statute of limitations calculator.

Should you hire a lawyer to get ELD data?

You are not legally required to hire a lawyer to request ELD data, but doing so is often necessary in practice because carriers rarely hand over this evidence voluntarily once they know a claim is coming. An attorney can send preservation letters immediately, pursue a subpoena if needed, and interpret the technical data alongside other evidence like dispatch records and maintenance logs. If you are evaluating options, What to Ask a Truck Accident Lawyer Before You Hire One covers useful questions to bring to that conversation, and Suing a Trucking Company: What You Need to Know explains the broader process of holding a carrier accountable.

Sources

• Federal Motor Carrier Safety Administration (FMCSA)
• Electronic Code of Federal Regulations (eCFR) — 49 CFR Parts 387 and 395
• National Highway Traffic Safety Administration (NHTSA)