Under what condition might a right-turn lane NOT be controlled by a traffic signal?

Answer: B — When separated by a barrier

A right-turn lane might not be controlled by a traffic signal when it is separated by a barrier. In this situation, the physical barrier creates a distinct separation between the right-turn lane and the traffic flow that would ordinarily be guided by traffic signals. This means that vehicles in the right-turn lane can proceed without needing to wait for a signal to change, as long as it is safe to do so. Other circumstances, such as the presence of yield signs or being marked for pedestrians, do involve some form of control or consideration that requires driver compliance with specific rules or caution. Likewise, if a right-turn lane merges with through lanes, it suggests that the traffic conditions may still adhere to signal controls, as they are part of a more significant intersection where signals are applicable. The separation by a barrier, however, establishes a unique condition where traffic signals may not influence movement in that lane.