One of RTD's new commuter rail cars waits in storage. 

(Nathan Heffel/CPR News)

A new commuter rail line from Denver's Union Station to Denver International Airport will start running in the spring of 2016.

The service, set to launch April 22, will be known as the Regional Transportation District University of Colorado A Line. It will be faster than light rail, traveling at up to 79 mph. The estimated travel time for the 23-mile ride is close to 40 minutes.

The Denver Post reports that the $9 fare buys a regional pass that riders can use for multiple trips in a single day.

The $2.2 billion project is being funded by local RTD taxes, a federal grant and money from Denver Transit Partners, which will build, operate and maintain the trains.