What happens when you start running 225 trains a day through a campus of 52,000 students?

The University of Minnesota is about to find out.

In preparation for the June 14 debut of the Green Line, university officials have taken extraordinary precautions to try to keep students, staff and visitors from wandering onto the tracks and into harm's way. That's no small task, especially for a generation notoriously glued to its cellphones.

The U has been rolling out all kinds of alerts, including a poster saying: "A train weighs 98 tons. YOU DON'T. Use caution near light rail tracks."

But everyone's a little nervous that caution may be in short supply.

"It is going to be a challenge to get the attention of students," says U spokesman Tim Busse. "They are routinely distracted. But at the same time, they're also smart and adaptable."

The Green Line will cut through the heart of the U as it travels along Washington Avenue between downtown Minneapolis and St. Paul, with three campus stops (the West Bank, East Bank and Stadium Village stations).

It will be sharing the same busy thoroughfare with bike lanes, buses and tons of pedestrians. "If we could get a battleship in there, we'd have every form of transportation possible," joked Busse.

One big concern is bicyclists, who often make up their own traffic rules. In this case, Metro Transit has created six "bike boxes" — green rectangles painted on the street — to give bicyclists a safe place to wait for the rail crossing light. It even created a two-minute video to show how they work.

Another big fear: that someone will try to beat a train through a crossing. The U hopes to drill home the message that it's not worth trying. "It's 45 seconds," said Busse. "You can spare the 45 seconds to stay safe."

The big safety campaign will kick into gear in the fall, with a special focus at freshman orientation. "We're going to have a lot of experience making sure all of this works even before school starts."

maura.lerner@startribune.com