The truck accident evidence that wins cases in Illinois mostly sits in the trucking company’s own systems: electronic logging device data, engine downloads, driver qualification files, drug testing records, maintenance histories, and camera footage. Federal rules let carriers destroy much of it within months, and some video overwrites within days. Whether your crash happened on I-294 or a two-lane road downstate, the race to preserve this evidence starts immediately.
After a serious crash, local police or the Illinois State Police respond, interview drivers and witnesses, measure the scene, and document their findings in an official crash report. In the most severe wrecks, trained crash reconstruction officers may prepare a far more detailed analysis. The report identifies the drivers, vehicles, insurers, and often the officer’s initial assessment of contributing factors, which makes it the natural starting point for any claim. In Illinois you can request a copy of a crash report from the investigating agency; the Illinois State Police explains how to obtain its reports online or by mail on its crash reports page.
A police report alone rarely wins a truck case, though. It is a snapshot taken by an officer with limited time and no access to the trucking company’s internal records. The deeper truck accident evidence comes next.
Federal law requires most commercial drivers to record their hours with an electronic logging device, or ELD, under 49 CFR 395.8. The device automatically tracks when the driver is driving, on duty, off duty, or in the sleeper berth. Those records matter because the hours-of-service rules in 49 CFR 395.3 generally limit property-carrying drivers to 11 hours of driving after 10 consecutive hours off duty, within a 14-hour window, with a 30-minute break after 8 hours of driving and weekly caps of 60 hours in 7 days or 70 hours in 8 days.
ELD data can show that a driver was over hours, had been driving for a long stretch before the crash, or logged patterns that suggest chronic fatigue. Under 49 CFR 395.8, carriers must keep records of duty status and supporting documents for at least six months, which means this evidence has a built-in expiration date if nobody demands its preservation.
Modern trucks also carry engine control modules and event data recorders that capture how the vehicle was being operated in the seconds around a crash. Depending on the system, this can include speed, throttle, braking, and fault codes. Reconstruction experts use this data to test the driver’s story against physics. If the driver claims he braked hard and the module shows no braking before impact, that single data point can reshape the entire case. Because the truck itself may be repaired, salvaged, or put back on the road quickly, downloading this data early is a priority in any serious injury case.
Trucking companies are required to keep a qualification file on every driver under 49 CFR 391.51, including the employment application, driving record checks, road test documentation, and medical certification. These files can reveal that a carrier hired a driver with a troubling history or kept an unqualified driver on the road, which supports claims against the company itself, not just the driver.
Federal rules also require post-crash testing in defined situations. Under 49 CFR 382.303, an employer must test a surviving driver for alcohol and controlled substances after a crash involving a fatality, and after certain injury or tow-away crashes where the driver receives a citation. Alcohol tests are supposed to happen within hours, and drug tests within 32 hours. Whether the company followed those rules, and what the results showed, is core truck accident evidence.
Brakes, tires, lights, and steering do not fail at random nearly as often as trucking companies suggest. Under 49 CFR 396.3, motor carriers must systematically inspect, repair, and maintain the vehicles under their control and must keep records of that work. Maintenance histories, driver vehicle inspection reports, and repair invoices can show that a company knew about a defect and kept the truck rolling anyway. Notably, the regulation requires these records to be kept for one year where the vehicle is housed and only six months after the vehicle leaves the carrier’s control, another reason speed matters.
Many fleets now run forward-facing and driver-facing cameras, and that footage can be the most persuasive truck accident evidence a jury ever sees. Video also lives outside the truck: traffic cameras, doorbell cameras, and security systems at businesses near the crash site may have captured the collision or the truck’s driving in the minutes before it. Most of these systems overwrite themselves on short cycles, sometimes within days.
Witness statements round out the picture. Independent witnesses who saw the truck drifting, speeding, or running a light carry real weight precisely because they have no stake in the outcome. Collecting their accounts while memories are fresh preserves testimony that may not be available two years later at trial.
The first move is a preservation letter, sometimes called a spoliation letter, sent to the motor carrier and its insurer demanding that the truck, its electronic data, logs, personnel files, and video be preserved. Illinois courts can sanction parties who destroy evidence they had a duty to keep, and a prompt letter creates that duty clearly and early.
Once a lawsuit is filed, formal discovery takes over. Lawyers serve document requests and interrogatories, subpoena records from third parties like brokers, shippers, and camera owners, depose the driver and company safety personnel, and hire experts to download and interpret the electronic data. Identifying every company in the chain matters too, because modern freight often moves through networks like Amazon Relay, where the company whose name is on the load is not the company that employs the driver. The legal rules about who can be held responsible continue to evolve, as we explained in our post on the Supreme Court’s decision in Montgomery v. Caribe Transport II.
Put the retention rules together and the picture is stark. ELD records may be kept for only six months. Maintenance records can lapse within months of a truck leaving the fleet. Camera footage may cycle out within days, the wreckage itself may be repaired or scrapped within weeks, and witnesses scatter. Trucking companies and their insurers know all of this, and they are under no obligation to volunteer evidence you never asked them to keep. Acting quickly, ideally within days of the crash, is the single best way to make sure the proof of what really happened still exists when your case needs it. An experienced Illinois truck accident lawyer can lock that evidence down before it slips away.
A real example from our firm’s practice: our client was rear-ended by a tractor-trailer on I-294 and was recommended for spine surgery. We recovered a $900,000 settlement. Every case is different, and past results do not guarantee future outcomes.
The police crash report, electronic logging device data, engine and event data, the driver's qualification and drug testing files, maintenance records, dashcam and surveillance video, and witness statements. Together they establish fault and expose safety violations.
Federal rules generally require ELD records of duty status and supporting documents to be kept for at least six months, and maintenance records for about a year while the vehicle is in service. After that, routine destruction is legal, which is why preservation letters matter.
First through preservation letters, then through formal discovery: document requests, subpoenas to brokers and camera owners, depositions of drivers and safety personnel, and expert downloads of electronic data.
If you or a family member was seriously hurt in a crash with a commercial truck, the evidence that proves your case is already at risk. Collins Law Group, P.C. moves fast to preserve driver logs, electronic data, maintenance files, and video, and we know how to force trucking companies to turn over what they would rather keep buried. We offer free consultations, and we handle truck accident cases on a contingency basis, so you owe nothing unless we win. Contact Collins Law Group today to protect your claim while the evidence still exists.
John D. Risvold is an equity partner at Collins Law Group, P.C. in Naperville, Illinois. He represents individuals and families in catastrophic personal injury and wrongful death cases, focusing on commercial trucking crashes, rideshare and autonomous vehicle litigation, medical malpractice and birth injury, and product defect claims. He has tried cases to verdict in Illinois courts, recovered more than $50 million for clients over thirteen years of practice, and has been named to Best Lawyers in America for Personal Injury Litigation and Illinois Super Lawyers.
This article is for general information only and is not legal advice. Reading it does not create an attorney-client relationship. Every case is different; if you have been injured, speak with a lawyer about your specific situation.
