Which of the following would indicate a traffic incident requiring assistance?

A situation where all travel lanes are blocked clearly indicates a traffic incident requiring assistance. When all lanes are obstructed, vehicles cannot pass through, which poses a significant safety hazard. This typically suggests an accident or some other major obstruction that needs immediate attention from traffic management or emergency response teams.

In contrast, normal traffic levels, heavy congestion without any incident, and all travel lanes open do not signify a need for assistance. Normal traffic levels indicate that everything is functioning smoothly, heavy congestion without an incident suggests that the slowdown is due to high volume but not an immediate threat, and open lanes signal that there are no obstacles that would require intervention.