ATLANTA (AP) — A new $1.4 billion international terminal is set to open in May at the world's busiest airport.The terminal at Hartsfield-Jackson Atlanta International Airport is set to open on May 16 and has been in the works for 12 years.Airport officials say it will be more than a sleek new launching pad for millions of passengers. They say it's also a "new front door" to Atlanta that can help shape the future of the airport.The terminal was first proposed in 2000 to deal with a surge of international travelers. Hartsfield handled nearly 10 million international passengers last year and regulators predict that number will grow to more than 13 million by 2015.It's the biggest expansion at the airport in more than 15 years.