What is the purpose of reflective triangles in a commercial vehicle?

The purpose of reflective triangles in a commercial vehicle primarily revolves around safety, particularly in situations where the vehicle is stopped or disabled. Reflective triangles are used as a warning device to alert other drivers of the presence of a vehicle that is not moving. When placed behind a stationary vehicle, these triangles reflect light from oncoming traffic, making the disabled vehicle more visible, especially in low-light conditions or during dusk and dawn. This visibility is crucial to prevent accidents and ensure that other drivers have enough time to react appropriately.

The other options do not align with the primary function of reflective triangles. Enhancing visibility during the day, indicating lane changes, and improving aerodynamics are not the primary purposes of these devices. Reflective triangles serve an important role in roadside safety by signaling to others that there may be a hazard ahead.