Nearly 2.7 billion trips taken during the quarter in the U.S., the "sixth consevutive quarterly increase," APTA said. All major modes registered gains.

APTA said heavy rail use rose 2.5%, paced by gains in 11 of the 15 systems APTA measured. Eighteen out of 28 so-called "commuter rail" (or regional passenger rail) systems reported ridership increases, with ridership up 1.7%. Bus ridership rose about 1%, APTA said.

"Since nearly 60 percent of the trips taken on public transportation are work commutes, public transit is a vital service for cities and towns nationwide," said APTA President and CEO Michael Melaniphy.

"In some areas of the country, local and regional economies are rebounding, and not surprisingly, public transit ridership is up in regions where jobs are increasing and employment is up," Melaniphy continued.

Moreover, "Even though gas prices declined in the second quarter, more people decided to take public transportation. This goes to show that there is a growing public demand for public transportation services and the next Congress and President must address this issue," he said.