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Why the 'A' Line to the airport needs one year of testing

On April 17, a married pair of RTD’s new commuter rail cars pulled into the Denver International Airport train platform for the first time under their own power.

But don’t lug your suitcase to one of the eight stations along the East Rail—A Line just yet. Safety and commissioning testing is expected to take a year.

Why an entire year? Simply put: safety is RTD’s first priority.

Because commuter rail technology is different than light rail, and is new to Denver, there is a more involved testing process that must take place before the trains can start carrying passengers.



The A Line will travel approximately 23 miles between Union Station in downtown Denver to the airport. A large portion of its route runs parallel to Smith Road, through several neighborhoods in Denver and Aurora.

RTD and its contractor, Denver Transit Partners (DTP), take the safety of these communities seriously.

You might have seen the trains running along Peña Boulevard since mid-April, but before the trains are tested along the entire line, each at-grade crossing will undergo dynamic and joint agency testing to ensure that the signals and gates operate correctly. Initial testing of all 14 at-grade crossings on the line was completed in early July.

When all crossings “pass” their final tests, trains will begin running the entire route to the airport. That will probably happen later in summer 2015. While full testing is underway, the crossings will be additionally secured with flaggers who will further alert vehicle and pedestrian traffic to stop.


And remember, stay away from the power lines. Even though you might not see trains, the lines that are up are electrified.

Next, you will see the trains begin their intensive testing period. Each married pair, two train cars coupled together, needs 1,000 miles of "burn in," meaning they need to operate on the track under electrical power with only testing staff on-board, before they are ready to carry passengers.

During this time, every inch of the train will be checked to confirm everything is in working order and safe.

In addition to the train testing, each operator of the trains will need to go through 160 hours of "throttle time," which simply means they will need to be out on the tracks operating the trains before service opens to the public.

RTD is working diligently to guarantee your future ride between downtown and the airport is the most convenient and safe option available.

The A Line is on track for a spring 2016 opening. Stay up-to-date on the progress of the line here.