Minnesota's first commuter rail line has gotten a dramatic boost -- from bus riders.

Ridership on the Northstar Link Commuter Bus was up 106 percent last month over May 2010, jumping from 1,697 rides to 3,499. The bus service, combined with climbing gas prices and increased familiarity with the Northstar commuter rail line, which runs from Big Lake to downtown Minneapolis, has pushed train ridership up by more than 6 percent over the first four months of 2011. Train ridership in April was up more than 16 percent from April 2010.

"Most people are finding out that the Northstar Link provides a stress-free, comfortable ride," said Stearns County Commissioner Leigh Lenzmeier, chairman of the Northstar Corridor Development Authority, which sponsors the bus service.

Not all of the bus riders are commuters heading to work. A mid-day Friday bus link, in which riders leave St. Cloud at 10:15 a.m. and arrive in Minneapolis at 12:45 p.m., has become increasingly popular. The regular scheduled Northstar Link bus meets Northstar trains in Big Lake seven days each week.

"Commuter rail is still new," Luci Botzek, Sherburne County deputy administrator, said of the Northstar line, which made its debut in November 2009. "It's a different animal from the bus and light rail. Change takes time.

"But the increased number of riders on the Northstar Link is encouraging. A lot of St. Cloud students and faculty are going back and forth to the Twin Cities. They're taking the train from Big Lake or Elk River, where most Northstar rides originate, as we expected."

What proponents of the $317 million commuter rail line did not anticipate were ridership projections that were well off the mark. Northstar fell 21 percent short of meeting projections in its first full year.

There have been few complaints about the train itself -- a quiet ride that avoids the traffic snarls of Hwy. 10 through Sherburne and Anoka counties. The train's on-time performance exceeded 97 percent last year, said Ed Byers, director of commuter rail for Metro Transit.

Half the train ridership is from Big Lake and Elk River, the two farthest and highest-priced ticket stops from the Target Field station in Minneapolis. Those top fares are "good for the system," said Botzek.

Currently, the train has stations in Big Lake, Elk River, Anoka, Coon Rapids, Fridley and at Target Field.

"Unfortunately, we're burdened with those original projections," Botzek said. "They probably weren't as scientific as they could have been. But they're out there now, and it's really tough to get rid of them."

Many of the bus riders who connect with the train in Big Lake are coming from or going to St. Cloud, the target destination for Northstar's Phase II, which would extend the 41-mile rail line another 30 miles west. But in the face of those first-year expectations and new leadership in Anoka County that seems more interested in building a train station in Ramsey, Phase II could be several years from approval.

"That decision is in the hands of the local authorities," said Sen. Amy Klobuchar, a supporter of the commuter train. "It's out of our hands in Washington."

Paul Levy • 612-673-4419