The Tron Lightcycle Power Run rollercoaster under development in Magic Kingdom’s Tomorrowland will force two other Disney attractions to temporarily close.

Construction of the coaster is already underway in a previously unused section of the park adjacent to Space Mountain.  Attentive guests walking near the smoking section between Storybook Circus and Tomorrowland can spot crews working through the trees.

As site clearing work wraps up, Disney has announced two rides will shutter temporarily as part of the construction project. The first affected will be the Walt Disney World Railroad, with the trains remaining parked at Main Street Station beginning in December.

“During this time, guests will be able to get an up-close look at the railroad and take advantage of one-of-a-kind photo opportunities,” Jennifer Fickley-Baker, editorial content manager for Disney World, wrote on the Disney Parks Blog.

Concept art of Tron coaster in Walt Disney World (Disney)

Disney did not say when the railroad, one of the park’s opening day attractions, will resume operations. Prolonged closures are not uncommon for similar attractions. The Disneyland Railroad was closed for a year while its tracks were rerouted for the California version of Star Wars: Galaxy’s Edge.

The other attraction impacted by the Tron coaster will be the Tomorrowland Speedway. Disney said it will close for a “portion” of 2019, have its track adjusted and then reopen in the summer of 2019.

The coaster itself, themed after Disney’s 1982 sci-fi film, will open in 2021. Its construction was announced at the 2017 D23 Expo in Anaheim, Calif., following its successful debut in Shanghai Disneyland. That version of the ride reportedly hits speeds of 60 miles per hour. If duplicated in the Magic Kingdom, it would dethrone Rock ‘n’ Roller Coaster as the fastest coaster at Walt Disney World.

The Tron coaster will be the biggest addition to the Magic Kingdom for Walt Disney World’s 50th anniversary in 2021. It will also be the first ride originally constructed for Shanghai Disneyland to be exported to the U.S.