What is the primary purpose of signal lights in vehicles?

The primary purpose of signal lights in vehicles is to communicate driver intentions. This function is essential for maintaining safety on the road. When a driver activates signal lights, they are informing other road users of their planned maneuvers, such as turning or changing lanes. This form of communication helps to prevent accidents by allowing other drivers and pedestrians to anticipate and respond appropriately to the actions of the vehicle.

By signaling in advance, drivers contribute to a more predictable roadway environment, which is crucial for safe navigation among vehicles and pedestrians. This system of communication among road users is fundamental to effective and safe driving practices, reinforcing the idea that clear communication can significantly reduce the likelihood of collisions.

The other options, while they may seem relevant, do not accurately reflect the primary function of signal lights. For example, signal lights do not indicate vehicle speed, warn of engine problems, or enhance a vehicle's appearance. Their sole purpose is to convey the driver’s intent to others on the road.