Service Adjustments from Sept. 19-20 Started Until Fri Sep 18 Starting late-evening tonight, and throughout the weekend, GO buses replace UP Express trains for planned construction. On Saturday, Sept. 19 and Sunday, Sept. 20, GO buses will run direct between Pearson Airport Terminal 1 and Union Station Bus Terminal. Service adjustments on Monday, Sept. 21:- Trains departing Pearson Airport Terminal 1 to Union Station, between 05:27 and 00:54, will arrive and depart 1 minute earlier than regularly scheduled.Select your station to plan your trip.