What is a common sign of someone not being aware of a motorcycle?

Not checking mirrors or blind spots is a significant indicator that a driver is not aware of a motorcycle's presence. Motorcycles can easily be overlooked by drivers, especially if they are in a vehicle's blind spot or are much smaller than other vehicles on the road. A lack of awareness can lead to dangerous situations, as drivers who do not perform these checks may not be prepared to yield the right of way or avoid a collision.

On the other hand, behaviors such as checking mirrors frequently or using turn signals consistently indicate that the driver is actively engaged and aware of their surroundings, including the presence of motorcycles. Speeding through intersections is a risky behavior that doesn't inherently relate to awareness of motorcycles but rather reflects a disregard for traffic laws and safety. Therefore, the option regarding not checking mirrors or blind spots more directly exhibits a lack of awareness of motorcyclists on the road.