The world's busiest airport for international travel is growing again. Dubai International Airport opened a new concourse yesterday with the arrival of a British Airways flight from London.Officials say the new $1.2 billion concourse will boost the airport's capacity from 75 million to 90 million passengers annually. Concourse D will be used by more than 70 international airlines flying in and out of Dubai International, by far the Middle East's busiest airport. It is linked to the airport's existing Terminal 1 by an airport train.British Airways and Royal Jordanian will be the first airlines to use the facility, with other carriers phasing in operations over the coming weeks. Dubai International surpassed London Heathrow as the busiest airport for international traffic in 2014.