Hartsfield-Jackson International Airport has delayed the opening of its new rental car center and SkyTrain line by about a month, pending further testing of the SkyTrain people-mover. “It’s to ensure the long-term reliability of the train,” said airport spokesman Al Snedeker. The rental car center and SkyTrain were originally scheduled to open Nov. 10, but the grand opening has been moved to Dec. 8. The SkyTrain will go from the airport to the Georgia International Convention Center and then onto the rental car center. The airport has been testing the train for most of this year, but decided to continue the testing, Snedeker said.