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No Fees Unless We Win

(608) 784-4370

What You Need to Know About Semi-Truck Black Boxes

If you’ve been involved in an accident with a semi-truck, the vehicle’s black box may play an important role in your legal claim. The black box records important information about a truck’s operation and status, which can help shed light on the crash and help you and your truck accident lawyer

 gather crucial evidence. Here is what you need to know about semi-truck black boxes.

Trucking accident recorded on black box


“Black box” is a broad term that describes a number of devices designed to record transportation data. There are three types of devices that are most commonly used in semi-trucks and fall under this definition, and they each capture different kinds of information.

An electronic control module is a system of computers and sensors that keeps tabs on different aspects of engine and vehicle performance. This system usually records the use and operation of things like the antilock brake, traction control, and transmission systems.

Because truck drivers are legally required to take breaks after a certain amount of time on the road, an electronic logging device monitors the hours of service in which the truck is in operation. It records movement, mileage, and time to ensure the driver is in compliance with the law.

An event data recorder logs the data of actions that occur just before a significant event, such as sudden braking or the deployment of airbags. This is perhaps the most helpful device when it comes to determining what happened in the moments leading up to a collision. 

A semi-truck may have one black box, multiple black boxes, or none at all. They are not required by law.


A black box can provide crucial details about what caused or contributed to an accident. For you and your truck accident lawyer, these details play a key role in establishing fault and building a solid case against the truck driver and their employer. However, many employers are hesitant to share black box data for this very reason. A truck accident lawyer may be able to legally compel an employer to release this information so you can collect the evidence needed for a strong claim.

Fitzpatrick, Skemp & Butler LLC is here to help you navigate the legal aspects of an accident case. Their truck accident lawyers have been serving La Crosse and Onalaska, WI, since 1982. They offer representation in accident, personal and work injury, and Social Security Disability claims. Call (608) 784-4370 to schedule an appointment, or visit their website to explore their services.