How Can I Prove Someone Merged Into My Lane and Caused a Crash?

 Posted on November 10, 2025 in Car accidents

Car accidents caused by one vehicle merging into another vehicle are common on busy Illinois roads. This is especially true in high-traffic areas like Park Ridge and the surrounding suburbs. But proving that another driver merged into your lane and caused the crash can be difficult, especially if the other driver says you were at fault.

If you were injured in a lane-change accident in 2025, you may be entitled to compensation. The key to a successful claim is having the right evidence. An experienced Des Plaines, IL car accident lawyer can help you build a strong case to prove the other driver’s fault. 

When Do You Have the Right of Way in a Lane Change? 

Illinois traffic laws require all drivers to stay in their lane and only change lanes when it is safe. Under 625 ILCS 5/11-709, a driver must stay in a single lane "as nearly as practicable" and cannot move into another lane until the move can be made safely.

That means if another driver drifted, cut you off, or did not use their signal before merging, they may have broken the law. That violation can serve as important evidence of negligence. However, proving what happened requires more than just your statement.

Evidence That Can Prove a Merging Driver Was at Fault

Lane-change crashes happen very quickly, leaving little time for witnesses and drivers to process what occurred. Because fault is not always obvious, and witness testimony may not be available, you will need other evidence to prove fault.

Experienced car accident attorneys know how to do this. Your attorney may use several forms of proof to establish that the other driver merged unsafely, including: 

• Dashcam footage or surveillance video: If your car or a nearby vehicle had a dashcam, the video may show the exact moment the other driver crossed into your lane. Many intersections and businesses also have security cameras that record passing traffic.

• Eyewitness statements: People who saw the accident may have noticed the merging driver’s actions before the crash. Their testimony can confirm your version of events.

• Vehicle damage patterns: The location of dents, scrapes, and broken parts can reveal the direction and point of impact, helping reconstruct who entered whose lane.

• Police reports: Responding officers usually note who they believe caused the crash, as well as whether either driver got a ticket. A citation for improper lane usage or failure to signal can be powerful supporting evidence.

• Accident reconstruction experts: In certain cases, professionals can analyze vehicle damage, skid marks, and road conditions to create a detailed reconstruction of the collision.

The sooner you begin gathering evidence, the better. Physical evidence like skid marks or debris can disappear quickly.

Who Can Sue if Both Drivers Merge Into Each Other? 

Insurance companies often try to deny or reduce compensation by claiming both drivers were at fault. Under Illinois’s modified comparative negligence law (735 ILCS 5/2-1116), you can still recover damages if you were less than 50 percent responsible. Your recovery will be reduced by your percentage of fault. That makes it even more important to have clear evidence showing the other driver caused the crash.

Call a Park Ridge, IL Car Crash Attorney Today

Proving that another driver merged into your lane is not easy, but you do not have to take this responsibility on by yourself. At Quinn Law Group, LLC, our experienced Des Plaines, IL car accident lawyer has helped countless injured drivers prove the other driver’s fault and get compensation after serious crashes. Call 847-232-7180 today to schedule your free consultation.