What condition is indicated by a sign for a "steep hill downwards"?

The indication of a "steep hill downwards" sign is primarily meant to alert drivers that they need to adjust their speed to maintain control of their vehicle. Descending a steep hill can significantly increase the speed of a vehicle due to gravity, which can make it challenging for the driver to maintain control and stop safely. Slowing down allows the driver to navigate the descent safely, reducing the risk of losing control and enhances the effectiveness of braking systems, which may overheat if used excessively.

In addition, it's crucial to consider the potential for road conditions that could affect traction, such as wet or icy surfaces, making it even more important to approach with caution. Thus, heeding the warning to slow down ensures a safer driving experience.