In what situation should you not move over for an emergency vehicle?

The correct answer, which states that you should not move over for an emergency vehicle when there is a median or barrier preventing lane change, is based on the safety considerations not only for yourself but also for the emergency responders. When a median or barrier exists, it typically indicates that it is unsafe or impractical for a vehicle to change lanes. Attempting to navigate around a barrier could lead to a dangerous situation, including potential collisions with other vehicles or obstacles.

Safety regulations emphasize the importance of following traffic laws while allowing emergency vehicles to pass safely. In situations without a barrier, a move-over is often required, but when a physical obstruction exists, it is both unreasonable and unsafe to change lanes. The other scenarios presented—heavy traffic, the emergency vehicle not responding to an accident, and having no other vehicles around—might involve considerations for yielding to emergency vehicles, but they do not inherently restrict the ability to move over as effectively as the presence of a median or barrier does.