GO Transit is warning commuters about big changes at Union Station starting today.

Major construction at the transit hub will result in many weekday trains departing from different platforms.

The changes come as crews begin the next phase of the Union Station Revitalization Project.

Platforms 11 to 13 will be closed along with the tracks that serve them.

“We have been letting them know for the past couple of weeks. We’ve been giving out flyers, we’ve been flooding the concourse with staff,” Metrolinx spokesperson Anne Marie Aikins told CP24 Wednesday morning.

A good portion of them will come for their train this afternoon and go, ‘Woah, what did you do with my train?’ So we need to prepare them for that so we are again going to flood our concourse with staff to help direct them and transit safety staff as well.”

Aikins said there are several signs posted to remind passengers about the changes.

“There are big signs on the doors, they can’t open the doors, they can’t go in the elevator," she added.

“If people do get up here, get on the wrong track someplace else and try to run across the track, because that is what people do, we really want to caution you trains come in here faster than you think they come in here and you’ll never win against a train. So we are really worried about that and making sure we have enough staff to educate them about that.”

For a full list of trains affected by the platform closures, visit GO Transit’s website.