What is one of the five elements of a traffic crash?

One of the five elements of a traffic crash is the involvement of at least one motor vehicle. This element is crucial because a traffic crash inherently involves vehicles and their interaction with one another or with other objects. Without the participation of a motor vehicle, the incident does not meet the definition of a traffic crash, as the term specifically pertains to collisions involving vehicles on roadways.

The other options do not align with the fundamental definition of a traffic crash. For instance, the notion that all parties must agree on the cause contradicts the reality that investigations often reveal differing perspectives and analyses. Additionally, the idea that a crash must be planned in advance mischaracterizes the spontaneous nature of traffic incidents, which typically occur without prior intention. Finally, the presence of witnesses can be vital in determining the particulars of how a crash occurred, serving as a resource for information rather than being a condition that must be excluded.