What does a yellow traffic light indicate?

A yellow traffic light serves as a warning signal to drivers that the light is about to turn red. It indicates the need to prepare to stop safely. When you see a yellow light, it's essential to evaluate the situation ahead: if you can stop safely before the intersection, you should do so; if you're too close to stop safely, continue through the intersection with caution. This signal is designed to ensure that drivers respond appropriately, helping to prevent accidents by encouraging them to reduce speed and be alert as they approach the intersection.

The context of what the other options suggest clarifies why they do not represent the correct interpretation of a yellow light. For instance, proceeding with caution would imply maintaining speed, and increasing speed is contrary to the intent of a yellow light, which is to provide a warning rather than a directive to speed up. Lastly, the idea that no action is required contradicts the purpose of the yellow light, which is meant to prompt drivers to be vigilant and prepare for a change in traffic conditions.