Big trucks commonly mean big consequences in an accident. That reality means when things go wrong, you may need more than just a police report.
Truck accident claims are rarely simple. They typically involve severe injuries, high insurance stakes, and companies that are ready to protect themselves. If you want your side of the story to hold up, you need solid evidence — and you need it fast.
In 2023 alone, 5,375 large trucks were involved in fatal crashes, according to the National Safety Council. That’s a 43% increase over the past decade, even as vehicle safety technology has advanced. The risk isn’t going away.
In this guide, we’ll walk through the 8 core pieces of evidence a Chicago truck accident lawyer relies on to build a strong, fact-driven case. Because when it comes to these accidents involving claims or commercial truck drivers, it’s unfortunately not about what happened or property damage. It’s about what you can prove. That’s what a truck accident requires.
1. Police Accident Reports
Police reports are often the foundation of a truck accident claim – and the process of acquiring a fair settlement.
These official documents provide a neutral third-party account of what happened, which can be incredibly helpful when there’s a dispute over fault or personal injury cases. Officers typically arrive at the accident scene shortly after the truck crash, speak with the drivers and witnesses, assess the damage, and create a report based on their findings.
A standard police accident report includes key details like the date, time, and location of the crash, the names and statements of those involved, any citations issued, and a diagram of how the collision occurred. Some reports may even gather evidence that includes the officer’s opinion about who caused the accident.
Lawyers use these reports to guide their investigation, support their client’s version of events, and begin building a truck accident lawsuit or case for determining liability. While not always admissible in court, they’re often persuasive in truck accident settlement negotiations and insurance claims.
2. Dash Cam or Traffic Camera Footage
Video footage can be one of the most direct and compelling types of evidence in a truck accident case. Whether it comes from the truck’s onboard dash cam, a nearby vehicle, or a city traffic camera, real-time footage can show exactly what happened in the moments before, during, and after the crash occurred.
This can include fault-attributing factors like speeding, sudden lane changes, ignored signals, or distracted driving.
Footage can also reveal important context — like weather conditions, road layout, or how other vehicles were positioned. Depending on the source, access to this footage can vary. Trucking companies may have dash cam video, while public intersections often have traffic cameras managed by local agencies. In some cases, witnesses may also have cell phone or dashboard recordings that can help piece together the full picture.
3. Black Box Data (Electronic Logging Device or EDR)
Most commercial trucks are equipped with a black box, also known as an electronic logging device (ELD) or event data recorder (EDR).
These devices automatically record key data about the truck’s operation — factors like speed, braking, engine activity, GPS location, and the driver’s hours of service. This kind of information is especially important in determining whether the driver was speeding, failed to brake, or violated federal regulations on rest and drive time.
However, accessing this data isn’t always easy. Trucking companies control these devices, and the data can be overwritten or lost if it’s not preserved quickly. That’s why acting fast — often with the help of a lawyer who knows how to send a formal preservation request — is essential in building a strong truck accident claim.
4. Driver Logs and Employment Records
Driver logs and employment records can uncover problems that go beyond the crash itself for the involved parties. Federal regulations limit how many hours a truck driver can be on the road without rest. Driver logs — whether handwritten or digital — track hours of service and can reveal violations that point to fatigue or overwork, both common factors in serious accidents.
Employment records add another layer to proving fault. They can show whether the trucking company had a pattern of hiring unqualified drivers, skipping training, or ignoring past safety violations. When these records reveal a history of negligence, it strengthens the case against the carrier and liable parties — not just the driver.
5. Truck Maintenance and Inspection Records
A poorly maintained truck is a danger on the road — and maintenance records can prove it or mechanical failures.
Commercial carriers are legally required to inspect and service their vehicles on a regular schedule. When they skip those steps or cut corners, critical components like brakes, tires, or lights can fail. Maintenance and inspection logs can reveal whether the truck involved in the crash had known issues that were ignored or never addressed.
A truck accident attorney in Chicago can use these records to show a clear pattern of negligence. If a company failed to fix a mechanical problem that later caused a crash, they may be held directly liable for the injuries that followed.
6. Eyewitness Statements
Eyewitnesses offer independent perspectives that can support or challenge the official narrative.
Their accounts help clarify what happened, especially when drivers give conflicting stories. Witnesses might notice details others miss — like a truck swerving, a driver texting, or a signal being ignored. These observations can strengthen or reshape a claim.
Collecting these statements early is important. Memories fade quickly, and small details can be lost within days. When stories conflict, attorneys compare them against physical evidence, video footage, and official reports to determine which version holds up.
7. Medical Records and Injury Documentation
Medical records create the link between the crash and your injuries. They show what harm was done, when it was treated, and how it has affected your life. This documentation is how to calculate medical expenses, medical bills, and damages — both current and future. Without it, the insurance company may question the severity or cause of your serious injuries.
These records must be thorough and consistent. Gaps in treatment or vague notes can weaken a claim. A strong truck accident case relies on clear, organized medical evidence that shows exactly how the crash changed your health and well-being.
8. Expert Testimony and Accident Reconstruction
Expert witnesses help clarify the details that evidence alone can’t explain. In serious or fatal truck accident cases, attorneys often bring in specialists to analyze the crash. Accident reconstruction experts review physical evidence — like skid marks, vehicle damage, and black box data — to recreate what happened and identify who was at fault.
Other experts may include doctors who speak to the long-term impact of injuries, or trucking industry professionals who can explain safety violations. Their insights add authority to a case or personal injury lawsuit and help a jury — or insurance adjuster — understand the full scope of what went wrong.
The Role of an Experienced Truck Accident Attorney in the Claim Process
A truck accident lawyer plays a hands-on role from the start of the claim process.
They move quickly to collect and preserve key evidence — like black box data, dash cam footage, and driver logs — before it disappears. They also know how to file legal requests to prevent trucking companies from deleting or altering records.
Beyond a thorough investigation, a Chicago truck accident lawyer handles negotiations with insurers and prepares for trial if needed. To do this, they manage the following tasks:
- Collect all relevant evidence to create the strongest claim
- Prove who was liable (can be several parties in a truck accident case)
- Calculate ALL the damages you suffered to place a value on your injury case
- Make sure you receive a fair settlement
Timing matters. The earlier a lawyer gets involved, the better the chance of securing evidence, recovering lost wages, and protecting your rights.
What a Strong Case Really Comes Down To
In a truck accident case, the facts don’t always speak for themselves. Someone has to do the work of finding them, connecting the dots, and making them matter.
That’s why strong evidence is the backbone of your story. And in a case this serious, your story deserves to be told clearly, powerfully, and with precision. Don’t risk waiting. If you or someone you love has been involved in a crash, the right legal support can make all the difference.
Midwest Injury Lawyers has deep experience with truck accident claims across Chicago and Illinois. We know how to investigate, build, and fight for cases that demand attention.
Contact us today for a free consultation and take the first step toward recovery — with the evidence and the advocacy to back it up.