What does tapping the brakes before stopping communicate to drivers behind?

Tapping the brakes before coming to a complete stop serves as a visual signal to drivers behind that a sudden stop is about to occur. This action causes the brake lights to illuminate, alerting following vehicles that the leading driver is slowing down significantly. By providing this warning, it gives other drivers behind ample time to react accordingly, helping to prevent rear-end collisions.

The other options do not accurately represent the intended signal communicated by tapping the brakes. For instance, changing lanes would typically involve using turn signals rather than merely tapping the brakes. Similarly, tapping the brakes does not suggest that the driver is increasing speed or that a turn is in progress. These actions would require distinct signals or indicators to convey the driver's intention.