Record ridership on Sound Transit drove the increase, with about 30.3 million boardings last year, an increase of more than 8 percent from 2012. The agency operates regional buses, the Central Link light rail and the Sounder commuter rail.
Spokesman Bruce Gray attributes the increase to the improving economy: "There's more jobs and more people riding the trains to get to work," he said.
Statistics from the American Public Transportation Association show that King County's bus system saw ridership jump more than 3 percent, as did Kitsap Transit in Bremerton. It was up half of 1 percent in Spokane.
However, the figures also show that bus ridership was down slightly in Olympia, Tacoma, Richland and Vancouver.
It was also down more than 12 percent in Everett. The Everett Transit System cut its service 15 percent in mid-2012 to balance its books, and it stopped offering free rides to seniors and some other populations - charging them 25 cents instead, said agency spokeswoman Sabina Popa.
"People travel a little differently when they ride for free than when they have to pay a fare, no matter how small it is," she said.
Washington State Ferries booked more than 22.5 million passenger trips last year, up a little more than 1 percent from 2012.