What is the purpose of alternating between high and low beams?

[Kelsey]

Alternating between high and low beams serves as a warning function. Here is an extended introduction about high and low beams: 1. Meaning: Alternating between high and low beams is used during nighttime encounters with oncoming vehicles, overtaking, and serves as a warning by switching between high and low beams. 2. Usage: High beams should be turned on in poorly lit conditions, such as on highways or rural roads. In well-lit conditions, as well as when encountering oncoming vehicles, following another vehicle, encountering pedestrians, or non-motorized vehicles, low beams should be used. This includes urban roads with streetlights. It is especially necessary to flash the lights when overtaking large trucks, as they have large blind spots and high chassis, so repeated flashing is needed to alert the truck driver and ensure safety before overtaking.