What must the extremities of an oversize vehicle or load be marked with during transport?

Marking the extremities of an oversize vehicle or load is crucial for ensuring safety during transport. Using red flags that measure at least 30 cm by 30 cm is a recognized practice to signal the presence of an oversized load. These flags increase visibility and alert other drivers of the potential hazards posed by the wider dimensions of the vehicle or load.

The red color of the flags is distinct and easily noticeable, making it effective during both day and night conditions. Proper placement of these flags at the extremities is essential, as it helps in preventing accidents by communicating the width and length of the vehicle or load to other road users. This marking requirement aligns with regulations for operating oversized vehicles, ensuring that the load is clearly visible and reducing the risk of collisions or misunderstandings on the road.

The other options, while they may have their own purposes, do not specifically fulfill the regulatory requirement for marking the extremities of an oversize vehicle or load as effectively as the red flags do.