Under which condition is it legal to turn right on red?

Turning right on red is permitted under specific conditions, which are primarily aimed at ensuring safety for both the driver and other road users. To legally turn right on red, a driver must first come to a complete stop at the red traffic signal. This complete stop is crucial because it allows the driver to assess the situation thoroughly, checking for any oncoming traffic, cyclists, or pedestrians who may be crossing the intersection or approaching from the driver's right.

This requirement prioritizes safety by ensuring that the driver is fully aware of their surroundings before making the turn, thereby reducing the risk of collisions. Additionally, it aligns with the general rules of the road that dictate drivers must yield to all other traffic and pedestrians before proceeding when facing a red light.

The other options are less safe or not entirely accurate. Simply having no traffic in sight does not absolve a driver from the responsibility of ensuring that it is safe to turn, as there could be unseen dangers. Turning whenever it is convenient lacks the adherence to safety protocols required by law. Lastly, turning right on red is not permitted at all intersections; there are specific signs indicating where this maneuver is allowed or prohibited.