Perry herself encouraged fans to keep an eye out for the shiny viral campaign and confirmed the truck announces the title of her new album and its release date.
"Find the #PRISM semi, take a picture and I'll RT you," she promised, catnip for her Katykats. "Don't worry, Los Angeles is just the first stop on the map."
The October release date will come early in the annual holiday rush, which is already slated to include Lady Gaga's "ARTPOP," due Nov. 11. Perry recently passed Gaga as Twitter's most popular woman.
In April, Perry told reporters she was halfway through her "Teenage Dream" follow-up, with Max Martin, Dr. Luke and Greg Wells among the collaborators.
Perry's had no shortage of projects since wrapping up the album's "California Dreams" tour: among others, she produced and starred in a 3D concert film (which also chronicled her split with ex-husband Russell Brand), "Part of Me"; reprised her role as Smurfette in the animated "The Smurfs 2," due July 31; and announced her latest fragrance, Killer Queen.
The multi-platinum "Teenage Dream" made Billboard history with five No. 1 singles, a single-album record for a female artist. In 2012, she was named Billboard's Woman of the Year.