Ridership on Metro Transit buses and trains increased for the fourth straight year as the agency provided nearly 81.4 million rides in 2013, according to figures released Thursday.

Boardings on the Northstar Commuter line were up 12 percent compared to the previous year and were among the reasons Metro Transit saw an overall increase of 315,000 rides system wide, agency officials said.

"Only twice in 32 years has Metro Transit ridership reached this level," said General Manager Brian Lamb. "In 2013, we provided five million more rides than just four years ago."

Surprisingly, the number of people using the Blue Line dipped 3.2 percent to just over 10.1 million. But gains on the Northstar Line (up by 86,963 rides) and urban bus service (up by 565,266 rides) more than offset the drop in ridership on the light-rail line from downtown Minneapolis to the Mall of America. Agency officials attributed the ridership drop on the Blue Line to weekend disruptions.

"We know that many weekend of construction and maintenance on the Metro system wore on our customers last year," Lamb said. "This year, we intend to repay that patience with the results - improved reliability and comfort on the Blue Line and the opening of the Green Line."

On Wednesday, the Met Council announced that the new light-rail line between downtown Minneapolis and St. Paul will begin on June 14. It will be called the Green Line.

The number of rides provided on Metro Transit's 53 freeway-oriented express routes rose slightly from 9.459 million in 2012 to 9.488 million in 2013 while numbers on the agency's six suburban local routes fell 1.9 percent from 1.661 million in 2012 to 1.630 million last year.

The bright spot by far was the Northstar Commuter Line. Customers took 787,239 rides, the highest ridership total since the line between Big Lake and Minneapolis began four year ago. Weekday ridership, the line's primary target, was up 17 percent.

"Although trains served more special events than before, new weekday commuters drove the strong gains in Northstar ridership," Lamb said. "The line's weather-proof reliability, comfortable ride and new onboard Wi-Fi service offer an increasingly attractive package for work travelers."

After declining by 117,000 rides from 2011 to 2012, urban local bus service saw a resurgence in 2013. Total ridership on Metro Transit's 60 routes was 59,300,133 and accounted for 70 percent of all trips taken on Metro Transit vehicles. Agency officials said extended evening and weekend bus service in the east metro and a partnership with Minneapolis Public School that expanded bus service for students at South and Southwest high schools fueled the gains.

Earlier this month, the Minnesota Valley Transit Authority said it also set a ridership record in 2013. The agency, which provides bus service in several communities south of the Minnesota River,said more than 2.7 million people boarded its buses and eclipsed the old mark set in 2008 by 67,500 rides.

Much of that jump was attributed to the Red Line, the bus rapid transit line that runs in bus-only lanes along Cedar Avenue between the Mall of America and the Apple Valley Transit Station. The line, which opened in June, accounted for 130,733 rides, MVTA officials said.