What does a "no U-turn" sign indicate?

A "no U-turn" sign indicates that making a U-turn at that intersection is illegal. This signage is specifically used to inform drivers that they are not permitted to reverse their direction by turning 180 degrees at that location. Such restrictions are often implemented in areas where performing a U-turn could be dangerous or cause significant traffic disruptions, such as busy intersections, highways, or places where visibility is limited. The presence of this sign is meant to enhance road safety by reducing the chances of collisions and ensuring a smoother flow of traffic.

The other possibilities suggest various conditions under which U-turns might be allowed, which is not the case when a "no U-turn" sign is present.