With both the US Open and New York Mets having events scheduled, significant traffic is expected in Queens next week, so authorities are urging fans to use public transportation.

The annual tennis event begins on Monday with Fan Week, some open practice sessions and qualifying matches at the Billie Jean King National Tennis Center in Flushing. The tournament ends on September 8.

Organizers said they expect nearly a million fans next week. The Mets have nine home games scheduled throughout the Open, including Fan Week.

“Take the train, take the bus,” MTA CEO Janno Lieber said at a news conference Friday. “All of those options are much, much better than sitting in traffic on the Grand Central Parkway or the Van Wyck (Expressway) or any of those other crazy congested roads and then paying $20 to $40 to park.”

Lieber said the transit agency will offer additional service on the 7 line and the Long Island Rail Road. The $5 to $7 fare on the LIRR takes passengers to the main entrance of the tennis courts, while the 7 line requires a seven-minute walk across the Flushing Meadows pedestrian bridge.

Queens Borough President Donovan Richards warned of potentially heavy traffic on the main roads surrounding the tennis center.

“Queens is the most diverse borough in the United States,” he said. “That’s because people come from the airport and get on the Van Wyck. Since they can never leave, they just stay in Queens.”

To promote public transit and the tennis tournament, the MTA is introducing three new train announcements from tennis stars, including Billie Jean King and Andy Roddick.

“Hey, New Yorkers, it’s Billie Jean King,” says the tennis legend in her spot. “The US Open is back in Queens. Remember, the best way to get to the Billie Jean King National Tennis Center is to take the MTA.”