How should standard hand signals be used according to the guidelines?

Standard hand signals serve as an important method of communication for drivers, especially when mechanical signals, such as turn signals, may not be functioning properly or are obscured. Utilizing hand signals adds an additional layer of clarity and safety on the road. While mechanical signals are a primary means of indicating intent to other drivers, hand signals reinforce these communications, ensuring that other road users understand the driver's intentions clearly. This is particularly beneficial in situations where visibility is compromised or when a driver may be traveling at slower speeds, such as on bicycles or motorcycles.

The incorrect options suggest limitations that do not apply to the effective use of hand signals. For example, while they are utilized by cyclists, they are not exclusive to them; all drivers can and should be aware of and utilize them when necessary. Furthermore, suggesting that only professional drivers should use these signals overlooks their importance for all road users in enhancing safety. The idea that hand signals are not widely recognized is misleading, as they are standardized and many drivers are familiar with them, making them a valuable part of road communication.