(515) 444-4000
Truck crashes often leave a scene of confusion, serious injury, and unanswered questions. What exactly happened? Was the truck driver speeding? Did they hit the brakes in time? One of the most valuable tools for answering those questions is inside the truck: the Event Data Recorder, or EDR.
Often referred to as a “black box,” the EDR captures important driving data that reveals how the truck was operating before and during a crash. This information can be a critical piece of the legal puzzle for people recovering from a collision when filing a personal injury claim.
Learn more about what an EDR captures and how skilled Des Moines truck accident lawyers can use it to build a strong personal injury claim on your behalf.
What Is an EDR?
An EDR is a built-in device found in many commercial trucks. It connects to the vehicle’s internal systems and tracks the driver’s actions in real time. When a crash or sudden event occurs, the EDR captures and stores a snapshot of what happened just before and after the incident.
Most older EDRs store around five seconds of pre-crash data. However, a recent federal rule now requires EDRs to capture 20 seconds of data at 10 recordings per second, offering a much clearer view of what led to the collision.
What Kind of Data Do EDRs Record?
Data from an EDR paints a technical picture of the moments surrounding a collision. It typically includes:
| Data Type | How It Helps Determine Fault |
| Speed Readings | Show how fast the truck was traveling before the crash, helping reveal speeding or unsafe speeds |
| Brake Activity | Captures when and how hard the brakes were applied, showing reaction time or failure to brake |
| Throttle Position | Indicates acceleration levels, which can suggest aggressive driving or failure to slow down |
| Steering Input | Highlights sudden swerves or lack of movement, pointing to distracted driving or poor control |
| Cruise Control and Fault Codes | Show whether automated systems were in use and flag mechanical issues contributing to the crash |
Some EDRs also record tire pressure, engine runtime, and warning alerts. Together, these offer a detailed look at the truck’s behavior, which is often more accurate than memory, witness reports, or driver statements.
How Attorneys and Experts Use EDR Evidence
Once EDR data is recovered, legal teams rely on it to build a case that connects technical findings to legal responsibility. Attorneys often work with accident reconstruction experts to analyze the data and prove fault.
EDR feedback can help:
- Validate Hours-of-Service Violations: When EDR data shows continuous vehicle operation exceeds legal driving limits, it can confirm violations of federal rest requirements.
- Support Claims of Distracted or Impaired Driving: Delayed braking or inconsistent throttle patterns may suggest the driver was distracted, fatigued, or under the influence.
- Identify Mechanical Failures or Neglect: Fault codes can reveal overlooked maintenance issues, such as worn brakes or sensor failures, which point to negligence by the trucking company.
- Disprove False Statements: EDR readings can contradict claims made by the driver or carrier, such as incorrect speed reports or brake use during impact.
- Link Driver Behavior to Company Practices: Patterns in EDR data may expose broader safety issues, including inadequate training, unrealistic schedules, or pressure to meet delivery times.
Preserving EDR Data
EDR evidence doesn’t last forever. The system may overwrite data within days, especially once the truck is moved, repaired, or returned to service.
Some trucks automatically erase stored information after a certain number of engine cycles. In other cases, maintenance crews or trucking companies may reset the system, sometimes intentionally, before anyone can review it.
To prevent this, your Des Moines truck accident attorney can send a legal notice called a preservation letter, requiring the trucking company to protect all EDR data immediately. Timing is critical. Once the truck returns to operation, that evidence could vanish.
Quick legal action helps lock in this data before it’s lost. Without it, your case may rely solely on witness statements or incomplete records, which often benefit the trucking company, not you.
Talk to a Qualified Truck Accident Attorney Today
A crash with a commercial truck can leave you dealing with far more than physical injuries. Medical bills, lost income, and unanswered questions often follow, and facing a powerful trucking company alone can feel overwhelming.
At Mueller, Schmidt, Mulholland & Cooling, we help victims and families in Des Moines reclaim their lives after a serious truck accident. Our attorneys quickly secure critical evidence like EDR data, work with accident reconstruction experts, and pursue every available path to compensation.
We’ve recovered $10 million in a case involving an 18-wheeler crash and $5,000,000 for a client injured in a separate trucking accident. Results like these reflect our commitment to thorough investigation, strategic action, and standing up to insurance companies who try to limit your recovery.
Contact us today for a free consultation. We’ll review your case, answer your questions, and help you pursue the settlement you deserve.
Categories
Providing Unmatched EXPERIENCE On Your Case When you find yourself in a situation where you’ve been treated unfairly or you’re in the middle of a legal disagreement, it can be difficult to know what your rights are and how to proceed.
