A red arrow at an intersection indicates that?

A red arrow at an intersection signifies that vehicles must stop and cannot proceed in the direction indicated by the arrow. This traffic signal is designed to enhance safety by controlling the flow of traffic at intersections. When a red arrow is displayed, it clearly communicates to drivers that they are required to halt their movement in the direction of the arrow, effectively preventing any turns and helping to manage the interactions between vehicles and pedestrians.

In the context of the other choices, it’s important to note that turning traffic must entirely stop; therefore, the option indicating that traffic can proceed with caution or that vehicles can turn right is incorrect. This maintains the regulation that drivers must comply with traffic signals to ensure safe driving conditions. The clarity of the red arrow's message is crucial in keeping intersections safe and orderly.