SALT LAKE CITY — Utah Transit Authority ridership increased 34.1 percent during the first quarter of the year compared to the same time frame a year ago, thanks to the opening of two new TRAX lines and higher gas prices.

The Utah Transit Authority reports Salt Lake City had the nation's second biggest increase in ridership for light rail in the country, second only to Memphis at 45.7 percent. The increase in FrontRunner ridership was in the top 10 nationwide for commuter rail, at 8.5 percent, ninth in the country.

A new report from the American Public Transportation Association crunched the numbers for 27 light-rail systems across the country. Twenty-five of the 27 reported increased ridership. When combining bus, light rail and commuter rail service, public transportation ridership jumped 5 percent in the first quarter of 2012 over the first three months of 2011. The combined service increase for UTA year over year was 7.5 percent.

The APTA believes gas prices are a large part of the reason behind the increase, and UTA spokesman Gerry Carpenter agrees.

"With gas prices nearing $4 a gallon, people are looking for alternatives to filling up their gas tank all the time," Carpenter said.

But gas prices don't entirely account for the extremely large growth in TRAX ridership locally, which has prompted UTA to add cars to trains during high traffic times and increase the number of trains running. He also attributed the increase in ridership to the new West Valley and Mid-Jordan TRAX Lines, which were added in August of last year.

"The new configuration with the red, blue and green lines, and the higher frequency in the core areas between Murray and downtown have really increased our ridership overall on light rail," Carpenter said.

Michael Melaniphy, APTA's president and CEO, points out nearly 60 percent of trips taken on public transit are for work commutes.

"In some regions of our nation," Melaniphy said, "the local economy is rebounding and people are commuting to their new jobs by using public transportation."

Carpenter said UTA has tracked weekly gas prices going back more than 10 years and can compare them to ridership numbers for the same times. Almost every time gas prices have spiked in the region, there has been a correlating increase in public transportation use. Typically, some of the new riders revert to their old commuting method once gas prices drop; but not all of them do, resulting in a net increase in ridership over time that continues to grow.