No reason has been given for The Disney Company’s just-announced decision to delay the opening of its first entertainment theme park in China, but speculation is that the extra time may be necessary to complete the extensive transportation upgrades needed to get visitors to and from the planned Shanghai Disneyland, located in the city’s thriving Pudong district

The upgrades include a high-speed rail system and a subway, both seen a critical to connecting the new park with an estimated 330 million potential visitors that live within a three-hour radius of the park. The English-language China Daily newspaper reported last month that sources within The Shanghai Shendi Group, Disney’s joint-venture partner on the project with a 57-percent share, had indicated there might be difficulties with the 2015 opening.

Originally slated to open early this year, the park—Disney’s third in Asia after Hong Kong and Tokyo—is now expected to open sometime in the spring of 2016. Shanghai Mayor Yang Xiong recently said the basic construction of the park and ancillary facilities would be completed this year, but when asked for an exact opening date, said, “I guess we still need to do more preparatory work and have further discussions with the Walt Disney Company as well as other Chinese partners.”

Ground was broken on the first phase of the $5.5 billion project four years ago and work is underway on two hotels, a “Downtown Disney” shopping center and the largest Disney castle in the world—the Enchanted Storybook Castle, featuring a winding staircase that will take visitors on a ‘Once Upon a Time’ adventure. The Shanghai park will also feature the “Garden of the Twelve Friends,” a five-acre green space with lush cherry blossom groves featuring 12 massive mosaics depicting Disney characters fashioned as the signs of the Chinese Zodiac.

“The park will take full advantage of advances in technology that will fully immerse our guests in our stories and attractions so that they will have happy experiences like never before,” Disney said in a promotional statement.

In addition to its Hong Kong and Tokyo theme parks, and the planned Shanghai park, Disney operates venues in Paris, France, California, and Florida.