What sign either indicates a reduction in speed or a caution about certain conditions?

The advisory speed sign is specifically designed to inform drivers about a recommended speed limit for certain conditions, which often relates to road curves, construction areas, or other situations where a reduction in speed may be necessary for safety. These signs provide guidance based on the current conditions of the road, helping drivers make informed decisions about their speed.

The purpose of advisory speed signs is to enhance safety by suggesting a speed that is safer than the posted regular speed limit under specific circumstances. They do not carry the force of law like regulatory signs (e.g., stop or yield signs), but they are crucial for navigating potentially hazardous road conditions safely.