Crashes that occur within the accident scene or "Q" area due to an original incident are called:

The term "secondary crashes" refers specifically to additional accidents that occur within the vicinity of an initial incident, often as a result of the changes in traffic patterns, driver reactions, or hazards introduced by the original crash. These secondary incidents typically happen while responders and others are present at the scene of the original crash, creating a dangerous environment that can contribute to further collisions.

Understanding the context of how secondary crashes occur is crucial for law enforcement and first responders. The presence of stalled vehicles, debris on the road, and distracted drivers can elevate the risk of further accidents. Proper management of the scene is essential to minimize the likelihood of these additional crashes.

The other terms in the question suggest related but distinct concepts. For example, "subsequent harmful events" and "tertiary crashes" might imply a further escalation or another layer beyond just secondary incidents. "Unplanned events" is too broad and does not specifically capture the nature of crashes that directly relate to the initial accident scene. By recognizing and reacting appropriately to conditions that may lead to secondary crashes, officers can help ensure the safety of all involved and effectively manage traffic incidents.