In matters of civil liability, for the obligation to repair damage to arise, there must be a causal link between the cause and the result. Thus, in motor vehicle traffic accidents, identifying the origin of the damage is not always straightforward when multiple circumstances converge that may have contributed to its occurrence.

When the victim or their relatives seek compensation from the party deemed responsible, courts rely on accident reconstruction experts to determine whether the injured party contributed in any way to the وقوع of the accident. From this analysis, two legal concepts emerge:

A. Contributory Negligence
This occurs when the damage is the result of the concurrent conduct of both the liable party and the victim.

• Common scenario: The injured party’s failure to comply with safety regulations, such as not wearing a seat belt or helmet, or using them improperly.
• Legal effect: The amount of compensation is reduced in proportion to the victim’s degree of participation in the outcome.

B. Exclusive Fault of the Victim
This applies when the conduct of the injured party is the sole cause of the damage, thereby breaking the causal link.

• Common scenario: A pedestrian who chooses to cross a high-speed roadway at street level despite the existence of a pedestrian bridge only a few meters away.
• Legal effect: As there is no liability on the part of the driver, the driver is absolved.

Proving the exclusive fault of the victim requires a much stricter evidentiary burden than that required to establish contributory negligence.

In fact, Mexican case law (First Chamber, registry number 2028383) has established a rigorous standard: for the defendant to be exonerated, they must prove that the victim acted with recklessness or negligence of such magnitude that it is equivalent to intent. Mere slight negligence is insufficient; gross negligence is required, such that the injured party must bear the consequences of their own conduct.

Conclusion
The complexity of traffic accidents lies in the analysis of their causes. Correctly distinguishing between the victim’s contribution to the damage and their exclusive responsibility is essential in determining whether the duty to compensate arises—or not.