Commuting into Toronto from the suburbs and beyond is already bad enough, but it's about to (temporarily) get a whole lot worse.

Anyone planning a weekend visit to the city using GO transit might want to look for an alternative means of travel, with two major rail lines shutting down and most trains cancelled to accommodate some much-needed track construction work.

If you use the Lakeshore West and Barrie GO Lines to get in or out of the city, get ready for a weekend of inconveniences, as the bulk of Lakeshore West GO train service will be suspended between Oakville and Union Station from Saturday (Nov. 20) until the end of service on Sunday.

If you're a Lakeshore West Line customer with tickets to see the Leafs face off against the Pittsburgh Penguins on Saturday night, there will be a few trains passing through the construction zone to get fans in and out of the heart of the city.

This includes Union-bound trains leaving Aldershot GO at 4:55 p.m. and West Harbour GO at 5:13 p.m. After the game, two trains will leave Union Station at 10:35 and 10:50 p.m., but if you miss those, you'll be stuck with a very long bus ride.

GO customers who use Long Branch, Mimico, or Exhibition GO stations will be left out waiting in the cold if they don't get this memo, and are advised to use TTC routes to connect with Union Station instead.

These closures are giving Metrolinx room to safely replace older sections of track and a switching station, which will allow for faster and more reliable travel along the line.

Now four weekends into the complex project, Metrolinx expects the track and switching upgrades to be operational before the end of the year, though it won't be fully complete until 2022.

If this significant closure wasn't already enough of a headache for regional commuters, Niagara trains service is also down. Customers travelling between Niagara Falls and Burlington are advised to use the GO bus Route 12 service, while replacement buses and refunds will be offered to WEGO ticketholders.

But wait, there's even more reason to stay home this weekend, as temporary changes to Barrie train service are planned for Saturday, with some trains not stopping at stations between Allandale Waterfront and Bradford GO.