No entry signboard image

Quick answer：

A 'No entry' signboard is a traffic sign that indicates a road or area is closed to all vehicular traffic. It is typically used to prevent unauthorized access or to redirect traffic. Such signs are usually square or rectangular with a red circle containing a black prohibition symbol (a black bar or circle) and the word 'NO' or 'NO ENTRY' in bold letters. They are commonly found at the beginning of one-way streets, dead ends, and areas where access is restricted for safety or security reasons.