The countdown to the opening of the city’s first new subway in more than 15 years has begun.

Officials from all three levels of government were on hand at the new Downsview Park Station on Friday morning to celebrate hitting the 30-day mark from the official opening of the new 8.6 kilometre Toronto-York Spadina Subway extension.

The subway extension was initially supposed to be up and running in 2016 but its completion date was pushed back amid numerous delays.

Once it officially opens on Dec. 17, the extension will become the first new subway to open in the City of Toronto since the ribbon was cut on the Sheppard Line on Nov. 22, 2002.

“We have a transit map right now that doesn’t look as a transit map should look for a city growing as fast as this city but we are in the process of changing that and today is an important step forward in that regard,” Mayor John Tory told reporters at Downsview Park Station. “The notion that we should have waited 15 years between the last time we opened a major subway project and today is not acceptable. It is not acceptable to the people; it is not acceptable to us.”

The Toronto-York Spadina Subway extension was initially projected to cost $2.6 billion, however the final price tag ended up coming in at $3.075 billion.

TTC staff have previously said that start up delays, scope and design changes as well as numerous claims and settlements with contractors were to blame for the cost overruns.

The completed extension includes the six new stations and three new commuter lots as well as TTC, York Region and GO bus terminals.

The extension will allow commuters to travel from the previous end of the line at Sheppard West Station to the new terminus point at Vaughan Metropolitan Centre in about 14 minutes.

“I have lived in the GTHA my entire life and I know we have accomplished a lot over the years but what we are going to experience on Dec. 17 is perhaps the single greatest transit achievement of my lifetime,” Ontario Transportation Minister Steven Del Duca told reporters at Downsview Park Station. “It is the first time that subway trains will leave the 416 and it will be the first time that a major institution in York University will have the connectivity of the subway.”