What does a yellow box junction signify?

A yellow box junction is designed to keep the intersection clear to ensure the smooth flow of traffic. The primary rule regarding yellow box junctions is that drivers must not stop in the junction unless their exit is clear. This means that if you approach a yellow box and there is no space to move through because vehicles are blocking the way, you should not enter the box. By following this rule, it helps prevent gridlock and allows emergency vehicles and other traffic to navigate through the junction more effectively.

In this context, the other choices do not apply to yellow box junctions. Emergency vehicle priority is a general traffic rule that applies in many scenarios but is not specific to yellow box junctions. Similarly, no entry for vehicles and parking permitted are regulations that pertain to different traffic control measures, not to yellow box junctions specifically. Understanding the purpose of yellow box junctions is crucial for maintaining safety and efficiency in traffic flow.