Light-rail trains will begin rolling between St. Paul and Minneapolis on June 14 on the Green Line, nearly four years after construction started along the Central Corridor between the two cities.

The opening day, coming 60 years to the month after the last street car left the Twin Cities, will be marked with free rides and day-long community celebrations, said Susan Haigh, chairwoman of the Metropolitan Council.

The announcement was made Wednesday morning at the Union Depot station by Haigh and Knight Foundation Program Director Polly Talen.

The project, which cost a total of $957 million — half of it supplied by federal funds, with the balance divided among state, regional, county and city governments — required 18 new stations, in addition to five it will share with the Blue Line in downtown Minneapolis.

With six months left before the line begins service, it appears that all systems are go. Construction is 98 percent complete, more than half the line's 47 cars have been delivered and 61 new rail operators are being trained.

Laura Baenen, Metropolitan Council project spokeswoman, said that the only significant remaining construction is in downtown St. Paul.

There, workers are wrapping up a traction-power substation and the stairway-elevator at Central Station, as well as ironing out track switches near the Green Line's new operations and maintenance base in Lowertown.

Most of the work left to do is testing the new light-rail cars and training the operators. In about a month, Baenen said, regular testing of the cars will begin during the week.

"We will start seeing light-rail vehicles being tested as frequently as they will be in operations … every 10 minutes," she said.

In addition to train operators, Baenen said that 116 maintenance workers are being hired for the Green Line's Lowertown facility, which is adjacent to the Saints' ballpark site.

From downtown St. Paul, the 11-mile route begins at the Union Depot, winds north to the State Capitol and then turns west down the center of University Avenue. After crossing into Minneapolis, it turns into the University of Minnesota campus along Washington Avenue, crosses the river and then links up with the Blue Line, where it continues through downtown Minneapolis until reaching Target Field.