More people are using public transit nationwide, according to a new industry report released Monday, but Metro is diverging somewhat from national trends.

Nationally, transit use rose nearly 5 percent in the first quarter of the year compared to the same period of 2011, the American Public Transportation Association report shows. It credits high gas prices with fueling the trend.

Heavy rail systems like Metro averaged a 5.5 percent rise, while bus systems rose 4.5 percent.

Metro did not show the same gains on rail but surpassed the average on bus.

The rail system’s ridership was 2.8 percent higher than the first quarter of 2011, the report said. Bus ridership on the system, though, rose 7.9 percent. That gave the system a 4.4 percent ridership boost, just below the 5 percent national average uptick.

It’s not entirely clear why Metro is showing less of an increase on rail while bus is growing more. Metro has been improving how it counts bus riders, getting more accurate numbers, while also emphasizing express routes to save riders time.

Some commuters also may have cut back on Metrorail use when federal transit benefits dropped from a maximum of $230 per month to $125 per month on Jan. 1, opting for cheaper bus trips or other options as gas prices rose. The Washington region has an unusually high concentration of riders using the federal transit benefits.