Public transit in Southern Ontario is set to be completely changed over the coming years with the addition of tens of billions of dollars of new infrastructure, including four new subway projects in Toronto and a rapid transit line in Hamilton.

Though many of these additions — which include the infamous Ontario Line — have been in the works for some time, they just got one step closer to reality on Tuesday with a huge helping hand from the federal government.

Ontario and @INFC_eng are partnering to deliver the province’s historic four priority subways projects, bringing better, faster transit to the people of the GTA. Learn more about today’s funding announcement: https://t.co/ezBnhmx0pR pic.twitter.com/jnivWncuQ5

— Vincent Ke MPP (@vincentkempp) May 11, 2021

Prime Minister Justin Trudeau has confirmed that Ottawa will be stepping up to give a whopping $12 billion to existing transit plans for the GTHA, which will go toward undertakings including the aforementioned Ontario Line, the Scarborough Subway and Yonge North Subway extensions and the Eglinton Crosstown West Extension to Pearson.

The Ontario Line will run 15 stops from Exhibition Place to the Science Centre, while the Scarborough extension will bring an additional three stops to the city's east end, and the Yonge North extension, six stops from Finch up to High Tech Road.

The Crosstown Extension will add seven stops to the nearly-completed Eglinton West Crosstown LRT and will, like the others, run mostly underground.

BREAKING! PM re transit announcement: 12 billon re 4 subway projects, 3 in GTA, 1 rapid transit line in Hamilton. Investing in Ford govt’ Ontario Line, Yonge St N & Scarborough subway extension- inc. Vaughan, Markham, Rich Hill. Eg W LRT and rapid Hamilton line. #onpoli #topoli

— Cristina Tenaglia (@cristina_CP24) May 11, 2021

There will also be a new public transportation route coming for Hamilton — welcome news after an earlier and much-anticipated proposal for an LRT line in the city was nixed by Ford at the end of 2019.

Trudeau called the investment "historic" in a presser on the subject on Tuesday afternoon, given that it will help connect cities as far as Richmond Hill and Mississauga to the city, and move people quicker and more easily between parts of the region.

It's also money that the provincial government has been requesting for its ambitious transit expansion plans for years now. It is anticipated that the new subway lines alone will collectively have a daily ridership of more than 620,000 by 2041.

The Yonge North and the Scarborough Subway Extensions will also be good additions to the rapid transit system.

— David Cooper (@leadingmobility) May 11, 2021

Though that date may seem eons away, the bulk of the initiatives are due to be completed more than a decade earlier, by 2030.