Commuters from north Wash-ington County now are assured of ongoing weekday bus service into downtown St. Paul because of a new agreement with the Metropolitan Council.

The agency took over funding of Rush Line buses on Saturday, from four counties that had contributed money to keep them going. The change means that an experiment to test commuter bus ridership from Forest Lake south to St. Paul has ended and the route will become permanent, said Victoria Reinhardt, a Ramsey County commissioner who chairs the Rush Line Corridor Task Force.

"What we hoped was that it would prove itself," she said. "Transit should not be funded by counties, but we needed to prove this was viable."

Ridership has more than doubled since October 2010, when Washington, Ramsey, Anoka and Chisago counties invested about $118,000 apiece to start four morning buses inbound and four afternoon returning buses. The idea then was to measure public interest in what eventually will become a major commuter corridor along Interstate 35.

The longterm plan for the Rush Line envisions a bus rapid-transit lane, or even light rail, that would help relieve congestion along one of the east metro's busiest freeways. The full Rush Line corridor extends 80 miles to Hinckley, Minn., in Pine County, even though any transit service north beyond Forest Lake remains under study.

Projections indicate that the population along that stretch could exceed half a million by 2030 and that commuter traffic will grow accordingly. Currently the Rush Line has 180 passenger trips a day, or 90 riders each way.

The reopening of the Union Depot in downtown St. Paul and the 2014 launch of the new Central Corridor light-rail train will draw increasing numbers of passengers to east-metro transit, said Dennis Hegberg, who chairs the Washington County Board.

"That's when I think the ridership will move up more strongly, when that opens," he said. "Then you'll have a system where you can go to St. Paul or Minneapolis."

The Rush Line buses to St. Paul follow Route 285. Buses from Forest Lake into downtown Minneapolis follow Route 288, which Hegberg said are "standing room only." The Minneapolis buses started after the collapse of the I-35W bridge over the Mississippi River in 2007.

New park-and-ride lots will be built in Vadnais Heights and Lino Lakes, said Michael Rogers, project manager for the task force. Once they're completed, the Rush Line 285 buses would merge with another route, Metro Transit's 275, to reduce some overlap in service, he said.

The Rush Line route also will drop one early-morning route and one late-afternoon route that had little ridership, but overall bus service will increase. Rush hour express fares will remain the same at $3 each way, he said.

"All in all, it's a much higher level of transit service for the people out there," Rogers said.

Hegberg, who's been a promoter of transit development in Washington County, said the Forest Lake and Hugo areas will boom when the economic downturn ends, and public transit will draw new residents.

"The Forest Lake area is going to be an economic engine," Hegberg said. "We're going to see people take a look at those corridors and buy accordingly. I think that's one reason Maple Grove continues to boom during the recession. They look at amenities and walkability and other things." Maple Grove has a major transit station.

Reinhardt said the Rush Line task force will work with the Metropolitan Council to someday move commuter traffic past Forest Lake north to Hinckley.

"We need to make sure they understand the importance of that," she said.

Kevin Giles • 651-925-5037 Twitter: @stribgiles