Speed limits generally indicate:

Speed limits are primarily designed to reflect the safest driving speed under ideal conditions. This means that the limit is set considering factors like a clear, dry road and good visibility. While drivers can exceed the speed limit in specific situations, it is important to understand that doing so is illegal and unsafe under most circumstances.

In many situations, changing conditions such as weather, traffic, or road work can necessitate driving slower than the posted speed limit for safety. Therefore, the idea behind suggesting that speed limits indicate the fastest speed you may go if conditions are ideal aligns with the intent of establishing these limits, promoting safe driving practices, and protecting all road users.

Understanding this concept can help drivers make more informed decisions on the road, taking into account the context and conditions they are currently facing.