The Double Roundabout is a highway that appears in the episode "Tutor Sauce."
It is a normal highway with many curves and turns, including one curve reminiscent to a figure 8 shape. It has many various road signs, such as some reading "Do not cross" or "Keep left." It has buildings around it and seems to be fairly busy.
Role in episode
Mr. Krabs teaches SpongeBob how to drive a boatmobile in this highway. He thinks SpongeBob does better in driving in a lot of danger potential situations, so he takes him to the Double Roundabout. SpongeBob gets nervous about driving on the double roundabout, so Mr. Krabs says his pet snail Gary can drive through it, which turns out to be true.
Once SpongeBob is about to try driving through it, a police officer stops them and says it is illegal to let a snail or any other animal drive a boat, which makes Mr. Krabs sentenced to a class in Mrs. Puff's Boating School.