Future commuters line up to check out the first of four stainless steel cars during a ribbon cutting ceremony Dec. 2 at Denver Union Station. The cars will transport passengers from Denver Union Station to Denver International Airport have arrived from their assembly plant in Philadelphia and they promise to get passengers to or from the airport in 35 minutes.The East Rail line will make six stops during its 23-mile trip from Denver to DIA and will connect light rail lines throughout the metro region, including Aurora's Interstate 225 line. (Marla R. Keown/Aurora Sentinel)

DENVER | Denver is celebrating its new train service between downtown and the airport.

Future commuters line up to check out the first of four stainless steel cars during a ribbon cutting ceremony Dec. 2 at Denver Union Station. The cars will transport passengers from Denver Union Station to Denver International Airport have arrived from their assembly plant in Philadelphia and they promise to get passengers to or from the airport in 35 minutes.The East Rail line will make six stops during its 23-mile trip from Denver to DIA and will connect light rail lines throughout the metro region, including Aurora's Interstate 225 line. (Marla R. Keown/Aurora Sentinel)

The train — officially called the University of Colorado A line — began running between Union Station and Denver International Airport on Friday filled with dignitaries.

Paying passengers are expected after a ceremony to celebrate the opening.

The 23-mile trip takes about 37 minutes and cost $9 each way.

Riders can take the new train for free on both Friday and Saturday.