ELI5: Explain Like I'm 5

Advisory speed limit

An advisory speed limit is a speed limit that is recommended, but not required, for a certain stretch of road. Advisory speed limits are posted with a yellow sign that has a black number on it. This number will tell you the speed that is considered to be safe and reasonable for traveling on that road. Drivers can choose to go faster or slower than the advisory speed limit, but they should never go too fast or risk being ticketed by the police.