The "No Overtaking" sign is a traffic sign that prohibits motor vehicles from overtaking other vehicles. This prohibition generally applies to all motor vehicles except for some exceptions like two-wheeled mopeds and motorcycles without a sidecar. The sign indicates that overtaking is not allowed from the point where the sign is placed until an "End of Overtaking" sign is encountered. This rule helps maintain safety on certain road stretches where overtaking could be dangerous.

The sign is usually represented by a circular sign with a red border and depicts two cars, with a red line or other indication forbidding overtaking. The design and exact representation may vary slightly by country, but the principle remains the same. In some countries like the USA, this is known as a "No Passing Zone" with rectangular black-on-white signs and solid yellow lines on the road marking the limit for overtaking.

This sign is also used for specific vehicle restrictions in some regions, such as prohibiting only trucks from overtaking while allowing smaller vehicles and motorbikes to do so.

In summary, the no overtaking sign is a prohibitory traffic sign aimed at preventing vehicles from passing one another in certain road sections for safety reasons.