How to Prove Someone Was Speeding in an Accident

How to Prove Someone Was Speeding in an Accident 

March 24, 2026
By Rhine Law Firm, P.C.

To prove someone was speeding in an accident, evidence such as skid marks, vehicle damage, eyewitness testimony, traffic camera footage, or data from the vehicle’s event data recorder (black box) is used to demonstrate that the driver exceeded the speed limit at the time of the crash. 

Serious and fatal injuries increase significantly when the crash involves cars traveling at high speeds. According to the National Safety Council (NSC), speeding was a contributing factor in 29% of traffic fatalities in 2023.  

Fortunately, modern tech can accurately determine speed. Trust an experienced car accident lawyer at Rhine Law Firm, P.C. to investigate your case and gather evidence to support your claim to hold the defendant accountable for your losses.   

“Our clients’ best interests are at the forefront of everything we do at Rhine Law Firm, P.C. You can expect our attorneys to give you the personal attention you deserve.” 

Black Box Data 

An event data recorder, commonly known as a black box, records key information before, during, and immediately after a crash, including: 

  • Vehicle speeds 
  • Acceleration and deceleration   
  • Braking  
  • Steering input or wheel angle 
  • Airbag deployment 
  • Seatbelt usage  

While event data recorders have been used in some vehicles since the 1970s, federal regulations have required them in most new passenger vehicles manufactured since 2012. Unless the car that hit you was made in 2011 or earlier, black box data should be available. 

Too Fast for Conditions 

To prove speeding, it’s not always necessary to show the driver exceeded the posted limit. In North Carolina, a driver may be found at fault for going “too fast for conditions.” This is a legal standard that applies when a driver fails to adjust their speed for adverse conditions, such as heavy rain, fog, or a flooded roadway.  

Even if they were within the speed limit, evidence such as road and weather conditions, witness statements, and black box data can support a claim that they were driving too fast for the situation, contributing to the crash. 

Surveillance Video 

Surveillance footage, from municipal traffic cameras, business security systems, residential doorbell cameras, or dashcams, can provide critical, time-stamped evidence of a vehicle’s behavior leading up to the crash. This type of footage can be analyzed frame by frame to estimate speed, verify traffic signal compliance, and corroborate witness testimony, making it a powerful tool for establishing fault in speeding-related accidents.  

Accident Scene Photos 

If possible, take photos of the entire accident scene from many angles, including wide shots and close-ups. Include not only the damage done to vehicles but also any vehicle debris or skid marks. The faster a vehicle travels, the longer it takes to come to a complete stop. 

 In many cases, the length of the skid marks can be analyzed to help estimate the vehicle’s speed at the time of braking. However, factors like road surface, tire condition, and braking force also affect skid length. A skid speed calculator can measure these elements. 

Police Reports 

The police report includes details in the immediate aftermath of a crash, including whether speeding played a role. They observe the physical evidence and road and weather conditions, question the drivers, and have access to radar or lidar devices. Radar determines speed by measuring changes in radio wave frequency, while lidar uses laser pulses to calculate speed based on distance over time. 

If the driver was issued a speeding ticket after the accident, that citation is additional proof that the vehicle was speeding. 

Eyewitness Accounts 

Anyone who witnessed the accident can testify to the circumstances of the collision and the speeds involved. If possible, obtain the names and contact information of any eyewitnesses who were present at the scene.  

Accident Reconstructionists 

Accident reconstructionists are trained experts who analyze how a crash occurred by recreating the moments leading up to and including the impact. They examine physical evidence, such as skid marks, vehicle damage, and debris patterns, to estimate the speed and angles of collision. By assessing the extent of vehicle damage, they can estimate the energy involved, which correlates with speed.  

They also use event data recorder (black box) information and time-distance calculations to determine the speed of a vehicle between two points. This analysis can provide compelling evidence, even in the absence of eyewitnesses or surveillance footage. 

Consult a Lawyer as Soon as Possible 

In North Carolina, the statute of limitations for filing a personal injury lawsuit after a car accident is three years from the date of the collision. However, it is crucial to contact an attorney as soon as possible.  

Valuable evidence, including black box data and surveillance footage, may be erased or recorded over within 30 days or even less. Your lawyer can obtain a court order to preserve black box evidence if the car owner or lessee refuses to share that information.  

Schedule a Free Consultation with a Wilmington Car Accident Attorney 

If you were seriously injured in a car accident due to another driver’s negligence or recklessness, consult an experienced Wilmington personal injury lawyer at Rhine Law Firm, P.C. We have 30 years of experience standing up to insurance companies, and we won’t be intimidated.  

Schedule a free, no-obligation consultation today. We work on a contingency basis, so there is no fee unless you receive compensation.  

About Us

Rhine Law Firm, P.C. serves clients throughout North Carolina and nationwide, specializing in complex civil litigation led by Joel Rhine. With expertise in personal injury, car accidents, property damage, sex abuse, and more, the firm is passionate about taking on challenging cases. They emphasize providing personalized legal representation, prioritizing their clients’ best interests while offering state-of-the-art legal strategies. Rhine Law Firm’s dedicated attorneys enjoy the fight for justice and are committed to guiding clients through complicated legal processes. The firm offers free consultations, flexible appointment scheduling, and Spanish language services.

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