A new subway that will take commuters from Vaughan to Union Station in an estimated 42 minutes officially opened to the public today.

TTC riders on Line 1 will finally be able to hop on the Toronto-York Spadina Subway Extension on Sunday, with six new subway stops to Downsview Park, Finch West, York University, Pioneer Village, Highway 407, and Vaughan Metropolitan Centre.

“This my final act as CEO of the TTC but I am also very proud of my team because a huge amount of effort goes into opening a subway extension,” TTC CEO Andy Byford told reporters at Sheppard West Station on Sunday.

“I couldn’t be prouder of my team today. This is the culmination of many years of work.”

Byford acknowledged the challenges the project faced over the years, including cost overruns that brought the price of the subway from a projected $2.6 billion to $3.2 billion, a number which doesn’t include additional costs that could arise from a legal battle between the TTC and contractors over unpaid claims.

“This project, it’s no secret, has face challenges, a myriad of challenges,” Byford said.

“The bottom line is at the end of the day, we did what we said we’d do. We reset the project back in 2015. I’ve said to the mayor, I’m bringing it in on revised time. I believe it can be on revised budget. We’ve still got some work to do with claims but we are well on the way of working through those.”

To mark the opening of the subway extension, the province is footing the bill to make the entire transit network free for TTC riders today.

Mayor John Tory and TTC Chair Josh Colle were among the first people to ride the subway extension on Sunday.

“I just think it is a great day for Toronto and what I’ve been saying the last few days, and I know Mr. Byford agrees, this city cannot stand still. We have to be doing this all the time,” Tory said at Sheppard West Station on Sunday morning.

“This city fell decades behind on transit and now we are trying to make up for lost time so that is another reason why today is so exciting because it is heralding a new era.”

The extension is the first new subway to open in Toronto since the Sheppard Line in 2002.

Colle said there are lessons to be learned from the issues that arose over the course of the project.

“We have to manage our big capital projects differently, and we are doing that now. I actually think the TTC is going to set the standard for not only transit agencies but municipal projects now around North America with what we’ve learned from this,” he said.

“The other thing we’ve learned is you need oversight on these projects too. You need a board and a council who doesn’t lose track of these projects and I think that was happening last term and that was something we fixed.”

The transit project was jointly funded by the provincial and federal governments as well as the City of Toronto and York Region.

Officials have estimated that the extension will result in about 36 million extra transit trips each year while eliminating about 30 million car trips.

“We know this will literally take tens of tens of millions of car trips off the highways of the Greater Toronto and Hamilton area, which is so important for our economy, for our quality of life, for our fight against climate change, which we’re working so hard on,” Ontario Transportation Minister Steven Del Duca said Sunday.

“It’s also going to give more people access to York University on a daily basis, to come up here to the 905… we know gridlock doesn’t respect municipal boundaries, that it is a regional problem and needs a regional solution. This is such a landmark day because it sends a clear message (that) we know we need a fix across the whole region.”