10 things you didn’t know about the A Line as it reaches a decade of service
As the A line reaches its 10th anniversary on April 22, RTD is celebrating with some nerdy facts about the train that’s helped millions get to and from the airport
RTD’s “Train to the Plane”–the A Line – will have helped customers skip bumper-to-bumper traffic and the hunt for airport parking for a decade on April 22. Here are 10 facts – one for each year of service – that you may not know about the A Line.
Written in the stars?
Beforethe commuter rail became voter-approved in 2004 as part of FasTracks, RTD had reserved the “A”to designate a future “Airport”rail service from downtown Denver to Denver International Airport(DEN)in 1997, when plans for rapid transit took shape. The A Line’s final rai lwas completed in 2014. Testing and safety compliance followed in 2015,all to prepare for the A Line’s official 2016 launch.
People power
Bringing the A Line to life took 7 million hours with an average of 800 employees working daily to fulfill the project. RTD partnered with Denver Transit Partners to finance, design, build, operate, and maintain the A Line under a 34-year concession agreement.
Faster than Earth’s fastest land animal
Traveling at speeds up to 79 mph, the A Line is faster than a cheetah and operates from Denver Union Station to DEN with travel taking approximately 37 minutes along the 23-mile track. The commuter rail is powered by overhead electrical lines.
Every 15 minutes
Miss your train? Another will be right behind it. For customer accessibility, the A Line departs every 15 minutes from Union Station from 8 a.m. to 8 p.m. and every 30 minutes thereafter in the evening and early morning hours. These hours remain identical to the service hours when the A Line made its inaugural trips.
Airport fare that beats gas and rideshare costs
While dynamic rideshare prices to and from the airport can range from $35-$85 – and gas is currently hovering around $4 a gallon across Colorado – RTD’s faresare a stable known quantity. This includes the Airport Day Pass, totaling $10 for a full day of transit. When the A Line wheels first rolled in 2016, the airport fare was $9, for comparison.With visitors able to continue their travel from the A Line to other RTD transit services to reach their final destination from DEN, the Airport Day Pass i sa rare value.
First-of-its-kind milestone
RTD’s A Line was the first in the nation to be built with Positive Train Control (PTC) technology from the ground up. PTC is a Federal Railroad Administration requirement for all passenger rail systems in the U.S resulting from the Rail Safety Improvement Act of 2008. The safety technology enforces speed limits, prevents movements through misaligned switches, and signals an operator to slow or stop the train, or automatically stops a train if needed.
On-time performance
When time matters for catching a flight, the A Line boasts high reliability. RTD’s train to the plane averaged 90% on-time performance in 2025, overall – a measurement of how closely trains adhere to the posted schedule.
Service you can count on
Service availability ranked even higher at 97.7% for the A line in 2025 – meaning nearly every scheduled trip ran as planned.
A decade of strong ridership
The A Line led RTD rail ridership through the pandemic. By July 16, 2024, the line had welcomed 50 million customers since its April 2016 debut. The A Line led RTD rail ridership overall throughout 2025 and into early this year: From January 2025 through February 2026 – the latest data available – another7,166,178 customers boarded the commuter rail to reach their destination. All told, roughly 59,400,000customers have traveled the A Line since opening day.
Finally, for the transit enthusiasts
There’s no shame in being an avid fan, and here are some metrics for those who can’t get enough. Each A Line railcar is 85 feet long and equipped with luggage racks. A single railcar weighs in at 140,000 pounds and four trains – or two married pairs – can hold up to 300 seated customers who are heading out on or returning from a new adventure.
Extra, extra
A decade in, the A Line remains RTD’s most popular rail lines for helping customers make connections from the heart of downtown Denver to the world. Inspired to plan your next trip to the airport via transit? Visit the NextRide trip planning tool.
See what A Line operators and customers had to say about the service to the airport in this special short video that commemorated the commuter rail line reaching 50 million customers in July 2024.
And, to learn more about RTD A Line and SkyRide options to the airport, visit here.