What shape does a trumpet interchange resemble?

A trumpet interchange is designed to facilitate the merging and diverging of traffic between a highway and a secondary road that does not have direct access to the highway. It features a specific design where one road ends at a point where it meets a highway, typically without additional turn lanes.

In this configuration, the shape resembles a "T" intersection because the main highway runs horizontally while the secondary road meets it perpendicularly at the top of the "T." This type of interchange is particularly useful for enabling vehicles to enter or exit the highway without the need for complicated merging patterns, allowing for smoother traffic flow and less congestion.

Other shapes do not accurately represent the design or function of a trumpet interchange. For example, a circular shape would imply a roundabout, which serves a different purpose in traffic management. A triangle does not convey the necessary directional flow at the interchange, while a square lacks the essential characteristics of the angles and directionality involved in such designs.