What Is Black Box Data, and How Can It Help My Truck Accident Case in Illinois?

 Posted on December 16, 2025 in Truck Accidents

As of early 2026, federal rules still require trucking companies to use electronic logging devices, which continue to capture significant operational data. If you are involved in a truck accident in Illinois, the black box inside the commercial vehicle can become a key source of evidence.

The term "black box" does not refer to a single device. Trucks may have multiple electronic systems, including logging devices and engine modules, that collect different kinds of data. Together, this information can help explain how a crash occurred.

Crashes on major Chicago highways such as I-90, I-94, and Lake Shore Drive often involve heavy traffic, so strong evidence can make a major difference. Speaking with Chicago, IL truck accident lawyers can help you understand how black box data may support your case.

What Is a Black Box in a Semi Truck?

A black box is an electronic device, often called an event data recorder or electronic control module, that stores details about how the truck operates. It can capture information, such as speed, braking patterns, and sudden movements. Some devices store several days of data, while others may keep only a short window of information before overwriting it. This information can help reconstruct the crash and provide a clearer understanding of what took place in the seconds leading up to the collision.

Can Black Box Data Show the Trucking Company Was Negligent?

Black box data can help show whether a truck driver or trucking company failed to follow required safety standards. In Illinois, negligence means failing to use reasonable care under the circumstances. For commercial trucks, that duty includes following traffic laws and operating the vehicle safely based on traffic, weather, and roadway conditions.

Electronic data can reveal how the truck was being driven in the moments before a crash. When compared to Illinois traffic laws, this data can help show why the crash happened. For example, 625 ILCS 5/11-601 says drivers must travel at a safe speed based on traffic, weather, and road conditions, not just the posted limit. If black box data shows the truck was going too fast for those conditions, it may help show that the driver did not follow the law.

This type of evidence can provide objective insight into whether the truck was operated safely and whether the trucking company met its legal obligations at the time of the accident.

How Do I Get Access to the Black Box Data After My Accident?

You cannot usually access black box data on your own. The trucking company controls the device and may not release the information voluntarily. An attorney can send a preservation letter, which is a written demand requiring the company to save the data. If needed, the attorney can also file motions in court to prevent the destruction or alteration of the records.

How Long After My Accident Can Black Box Data Be Retrieved?

The amount of time available depends on the specific device. Some black boxes store data for days, while others may keep it for several weeks. Although injury victims have two years to file a lawsuit under 735 ILCS 5/13-202, digital evidence does not last that long. Once the information is overwritten, it is usually gone permanently.

Acting quickly after a crash increases the chances of preserving the data. Talk to an attorney right away.

Schedule a Free Consultation With Our Chicago, IL Truck Accident Attorneys

Black box data can provide clear insight into how a truck was being operated before a crash and whether required standards were met. If you were injured in a collision, an attorney can take steps to preserve this information and explain how it may affect your case. Founded in 1997, Winters Salzetta O'Brien & Richardson, LLC brings decades of experience and attorneys with diverse practice backgrounds who understand how truck accident claims are handled. Call 312-236-6324 today to schedule your free consultation with our Chicago, IL truck accident lawyers.