Which of the following describes an interchange on the motorway?

An interchange on the motorway is specifically a junction where two motorways meet. This feature allows for smooth transitions between the different roads, facilitating the flow of traffic and reducing the likelihood of bottlenecks. Interchanges are designed to enable vehicles to change from one motorway to another without the need to stop, utilizing ramps and overpasses to achieve this.

The other options represent different aspects of motorway infrastructure but do not accurately define an interchange. A rest area offers facilities for drivers to take breaks but does not involve connections between motorways. A type of traffic light pertains to signal control for intersections, which is different from the design of interchanges that typically do not utilize traffic lights to manage the flow between motorways. Lastly, entrance to a service area highlights access to amenities such as food and fuel but does not correlate with the concept of a junction where two motorways converge.