What does a no entry sign indicate?

A no entry sign distinctly indicates that you cannot legally enter the roadway ahead. This sign is placed to control traffic and ensure safety by preventing vehicles from entering areas where they might conflict with oncoming traffic or where access is prohibited for other reasons, such as construction or hazardous conditions. It is vital for drivers to heed this warning to avoid accidents and to comply with traffic regulations.

The other options suggest conditions under which entry might be permissible, which is directly contradictory to the purpose of a no entry sign. Understanding this is crucial for safe and lawful driving.