What does a "no U-turn" sign communicate to drivers?

A "no U-turn" sign clearly communicates to drivers that making a U-turn is prohibited at the specific intersection where the sign is posted. The purpose of this signage is to enhance safety by preventing potentially dangerous maneuvers that could lead to accidents or disrupt the flow of traffic.

By indicating that U-turns are not allowed, the sign helps drivers make informed decisions about their routes without attempting a maneuver that could cause confusion or put themselves and others at risk. This prohibition is often in place where visibility is limited or where road conditions do not safely accommodate such turns.

In contrast to the other options, the sign does not imply any allowances for U-turns based on time of day, nor does it suggest that U-turns can be made under certain conditions or are encouraged for traffic flow. The explicit prohibition is straightforward and serves a vital role in traffic management and safety at intersections.