What is the recommended speed indicated by speed limit signs with yellow background and black numbers?

[DiAlan]

Rectangular signs with yellow background and black numbers indicate recommended driving speeds. Here is relevant information: Speed limit: Speed limits typically refer to the prescribed range of driving speeds for a certain length of road segment, primarily aimed at preemptively reminding drivers to reasonably control their speed in subsequent sections of the road ahead and to prevent the dangers of speeding. Speed limits are an indispensable and most critical aspect of road transportation safety. Zonal speed limits: Based on traffic laws and regulations or enterprise facility regulations, specific zones are delineated in practical situations, and the maximum driving speed for vehicles within these zones is standardized. Common applications of zonal speed limits include school zone speed limits, factory zone speed limits, and speed limits for external vehicles, among others. The ultimate goal of zonal speed limits is to reduce speeding accidents and create a safe and worry-free driving environment for people, vehicles, and objects in areas such as school campuses or factory zones.