Interstate Loud

"Interstate Loud" is the 52nd episode of the Sintopia animated television series Intertropolis & Routeville and the 52nd and final episode in the first season of the series. It is the 30-minute crossover special to the Sintopia television series Intertropolis & Routeville and the Nickelodeon television series The Loud House. The special is considered the episode of Intertropolis & Routeville according to Blanding Cassatt. The episode is directed and story by Jordan Cassatt and written and storyboard by Kimberly Blanding. It premiered on September 27, 2021 on Nickelodeon and January 10, 2022 on Sintopia and the production code is 127.

Plot
In the crossover episode with The Loud House and Intertropolis & Routeville, Lisa Loud accidentally leaves the teleportation portal on for too long while she's sleeping. Later, The Loud Family went to tell Lisa by waking her up that it's still on. Failed to shut down the portal, Lisa and the Louds ends up getting sucked in the portal, transporting them randomly into Intertropolis and Routeville (Highway City) and meeting I-48 and US 86.