Editor's note: updated July 2026 for New York's 2026 tort-reform changes.
In most car accident cases, the liability analysis is straightforward. A rear-end collision. A red light violation documented in the police report. A left turn into oncoming traffic. The police report, the witness statements, and the vehicle damage patterns tell the story. But some accidents involve disputed facts that the available evidence does not resolve on its own. In those cases, accident reconstruction may be the only way to establish who was at fault. This is done through expert analysis of the physical evidence to determine how the collision occurred. Reconstruction is not needed in every case. When it is needed, it is often the difference between a recovery and no recovery.
The decision to retain an accident reconstruction expert carries real weight. These experts charge substantial fees, typically $15,000 to $50,000 in a serious case. The final cost depends on the scope of the analysis and whether the expert testifies at trial. The investment makes sense when liability is disputed. It also makes sense when the potential recovery is large enough to justify the cost and when the physical evidence supports a reconstruction opinion. This type of expert opinion can change the outcome of a case.
What accident reconstruction involves
An accident reconstruction expert analyzes the physical evidence from a collision. Using physics and engineering, the expert rebuilds what each vehicle was doing before, during, and after impact.
The expert looks at vehicle damage patterns and crush depth. The point of impact matters. So do tire marks, roadway scuffs, and debris scatter. The expert also considers roadway geometry and grade, traffic signal timing, and sight lines. Visibility conditions, weather, and road surface conditions at the time of the crash all factor in. In modern vehicles, electronic data from event data recorders and vehicle control systems adds another layer of evidence.
Reconstruction experts typically hold engineering degrees in mechanical, civil, or biomechanical fields. Most carry specialized training through organizations like the Accreditation Commission for Traffic Accident Reconstruction (ACTAR) or the Society of Automotive Engineers. Their findings go into a formal report. That report includes calculations, diagrams, and sometimes computer simulations or 3D scene models.
When reconstruction is necessary
Reconstruction comes up most often in intersection collisions. Both drivers claim the green light. Witness statements and camera footage leave the dispute unresolved.
Signal timing data from the municipality shows when each light changed. Approach speeds calculated from vehicle damage and skid marks show how fast each driver was moving. Together, those two data sets can establish which driver actually entered on green.
High-speed collisions where the at-fault driver denies speeding often require reconstruction. The crush depth of the vehicles, the post-impact trajectories, and the distance from point of impact to point of rest all reveal the approach speeds. A driver who claims to have been traveling at the speed limit can be shown, through reconstruction, to have been traveling significantly faster.
Head-on collisions where one driver claims the other crossed the center line can be reconstructed from damage patterns and final resting positions of the vehicles. Multi-vehicle chain reactions with disputed impact sequences require reconstruction to establish which collision happened first and which driver started the chain. Collisions involving commercial vehicles are another common scenario. When the driver or company claims mechanical failure caused the crash, reconstruction evaluates whether the mechanical condition, the driver's actions, or both were responsible.
Pedestrian, motorcycle, and bicycle crashes often need reconstruction. The physics differ sharply from vehicle-to-vehicle collisions. Where the body came to rest, the injury patterns, and the vehicle damage can each help establish approach speed and the pedestrian's position at impact. When a driver claims the pedestrian stepped out without warning, reconstruction can assess whether the driver had enough time and distance to react.
The event data recorder
Most passenger vehicles made since 2014 contain an event data recorder, commonly called a black box. It records data from the seconds before and during a crash. The EDR captures vehicle speed, brake application, throttle position, steering input, seatbelt use, and airbag deployment. A trained technician downloads that data using specialized equipment. Once downloaded, it can resolve disputes about speed, braking, and driver inputs with far more certainty than witness testimony.
Commercial vehicles carry electronic logging devices and often more sophisticated recording systems. These capture GPS data, speed, hours-of-service records, and sometimes dashboard camera footage. The recording devices overwrite older data on a rolling basis. A preservation demand sent within days of the accident can capture data that would otherwise be gone within weeks.
EDR data often becomes the single most valuable piece of evidence in a disputed liability case. It answers questions about speed and braking that witnesses can only estimate.
Physical evidence must be preserved for reconstruction to work
The reconstruction expert needs the physical evidence to analyze. Without evidence, even the best expert cannot reconstruct the accident. This is why early evidence preservation is critical in any case where liability is disputed. Vehicle damage must be documented through detailed photographs from multiple angles before repairs begin. If the vehicle is being totaled and scrapped, the expert should inspect it at the tow yard before it is removed. The damage patterns, crush depth, and direction of force are information that cannot be reconstructed after the vehicle is gone.
Tire marks, debris scatter, fluid spills, and roadway conditions at the scene must be photographed and measured quickly. Rain, traffic, or routine road maintenance can erase scene evidence within hours. Police accident reports sometimes include basic scene measurements, but independent scene documentation is often needed for expert analysis.
Event data recorder information, the "black box" data in modern vehicles, must be downloaded before the vehicle is repaired, scrapped, or the data is overwritten. Many vehicles retain EDR data for only a limited number of ignition cycles or hours of operation. If the vehicle is driven or powered on after the accident, the pre-crash data may be overwritten. Commercial vehicles with telematics systems store data on company servers. Preservation letters must go to the carrier directly, not just to the vehicle itself.
Surveillance footage from nearby businesses and traffic cameras run by NYC DOT or the NYS Department of Transportation can be critical evidence. So can dashcam footage from vehicles near the scene. This footage can be overwritten in as little as a week. Evidence preservation letters sent within that first week can prevent its destruction.
Reconstruction and comparative negligence
Fault allocation drives settlement value in every New York car accident case. Since May 26, 2026, a claimant who bears more fault than the combined fault of all defendants is barred from non-economic damages entirely. Every percentage point the adjuster can shift toward the claimant carries real financial weight.
Reconstruction analysis can move that allocation in ways witness testimony alone cannot. When the defense argues the claimant was speeding, failed to yield, or was inattentive, reconstruction evidence answers with physics and data. That is a different kind of proof than competing accounts of what someone saw.
How reconstruction affects settlement value
A favorable reconstruction report fundamentally changes the carrier’s evaluation of a case. What was a he-said-she-said liability dispute becomes a case with scientific evidence supporting the plaintiff’s version. The carrier’s reserve increases. The settlement authority increases. Cases that may have settled for a discount because of disputed liability settle at full value because liability is no longer in genuine dispute. The cost of the reconstruction expert is worth every penny when it achieves the outcome it is intended. In cases where the damages exceed seven figures, the cost of reconstruction is a small fraction of the incremental recovery the expert’s analysis produces.
The defense retains its own reconstruction experts in serious cases. When opposing experts clash at trial, that battle often decides the liability dispute. The jury picks which analysis it finds more credible.
An expert with strong credentials, clear methodology, and careful documentation carries more weight. One who appears to have worked backward from a desired conclusion loses that credibility fast. Selecting the right expert and preserving the evidence they need is how the reconstruction battle is won.
How Schwartzapfel Holbrook uses accident reconstruction
At Schwartzapfel Holbrook, we retain accident reconstruction experts when the liability analysis requires it. From the first week of the case, we preserve the evidence the expert needs. That means detailed vehicle photographs, scene documentation, event data recorder downloads, and any available surveillance or traffic camera footage. In disputed liability cases, reconstruction analysis can be the difference between a defensible claim and one the carrier dismisses as a credibility contest between two drivers. We invest in reconstruction evidence with the same thoroughness we apply to the medical evidence supporting the damages case. Both are necessary for the outcome the client deserves.
Schwartzapfel Holbrook / Fighting For You
