You are driving an agricultural tractor with a maximum design speed of 40 km/h. You want to tow a type-approval-exempt trailer behind this tractor. What must you bear in mind here?

When towing a trailer with an agricultural tractor that has a maximum design speed of 40 km/h, it's crucial to follow specific regulations.

1. The maximum permissible speed of 25 km/h for this combination is mandated to ensure safety on public roads, particularly because the tractor itself is not built for higher speeds when towing a trailer.

2. Displaying a "25" speed sign on the trailer is required as it informs other road users of the lower speed limit, ensuring they can anticipate the vehicle's movement and operate safely around it.

The third option, regarding the need for a registered licence plate for the trailer, is not applicable in this specific situation because the trailer is exempt from type approval; thus, it does not require its own registration.

Correctly identifying these rules is essential for legal compliance and safety on the road. Understanding these regulations helps prevent accidents and ensures that all road users are aware of the capabilities and limitations of slower-moving vehicles.