COLUMBUS, Ohio (AP) _ A study that says the Port Columbus International Airport might not be able to handle the growing number of travelers flying to and from there over the next 15 years, has prompted a preliminary plan to replace the airport’s terminal.

Officials with the Columbus Regional Airport Authority have developed a $1.3 billion plan that would include a larger terminal located to the west of the current one, according to The Columbus Dispatch ((http://bit.ly/1EC3jCQ).

The study presented to the airport authority this week estimates the number of passengers could grow at an average pace of 1.8 percent per year. By 2032, the number of annual passengers could surpass 8 million, putting a strain on the terminal, the study said.

The plan calls for a terminal with 48 gates, a parking garage with 5,441 spaces and a separate rental-car facility, both within walking distance of the new terminal expected to cost $603 million. A ground transportation center would include space for a possible light-rail service between the airport and downtown Columbus.

The plan is still in the early stages, and the authority’s board of directors is not taking any immediate action, the newspaper reported.

“Something of this magnitude would require a 10-year planning and construction cycle,” board member William Heifner said. “So, if we had to do something in 2030, we’d need to start planning in 2020,” he said.

Elaine Roberts, the authority’s CEO, said the first phase would involve infrastructure improvements and construction of a rental-car facility. That facility is estimated to cost $181 million.

The number of passengers at Port Columbus was up 2.1 percent in 2014, to 6.4 million. For the first three months of this year, passenger growth is up 4.1 percent.

Roberts said faster growth could speed up the need for the new terminal.

“But the economy could change, the airlines could change, growth could be slower,” Roberts said.