PITTSBURGH -- Repairs to shuttle train tunnels at Pittsburgh International Airport could slow travel within the airport over the next two weeks, officials said.

Repairs to the tunnels began today and will cut the frequency of train trips by about half, said Jeff Martinelli, a spokesman for the Allegheny County Airport Authority, which operates the airport.

Outbound travelers are advised to get to the airport about 15 minutes early because of possible delays, he said.

Just one of the airport's two shuttle trains will operate between Monday and Saturday, when workers will replace wallboards in one of two tunnels. The second tunnel will be repaired between Oct. 1 and Oct. 5.

The repairs are the first since the half-mile-long tunnels opened in 1992.