RTD celebrates 10 years of A Line service
Train to the Plane boasts the highest ridership of RTD rail lines, serving more than 59 million customers since its launch
DENVER (April 22, 2026) –– The Regional Transportation District (RTD) is celebrating the 10th anniversary of the A Line today, the commuter rail service known as the Train to the Plane. The 23-mile A Line operates from Denver Union Station (DUS) to Denver International Airport (DEN), providing customers with fast, reliable connections to domestic and international travel. With more than 59,400,000 boardings since the service’s debut, the A Line’s utilization surpassed that of all other RTD rail services in 2025.
To mark a decade of the A Line, RTD held a media conference at 10 a.m. today with speakers including RTD General Manager and CEO Debra A. Johnson, RTD Board Chair Patrick O’Keefe, Aurora Mayor Mike Coffman, and Denver Transit Partners (DTP) Project Manager and CEO Nate Morgan.
“Celebrating the 10-year anniversary of the A Line is truly a milestone for the entire region. From day one, this service has strengthened connections and created opportunities for customers and visitors alike, expanding access destinations throughout the Denver metro area.” Johnson told attendees today. “The launch of the A Line in 2016 made it easier than ever to reach key activity centers while supporting economic growth and sustainable mobility.”
When the A Line launched in 2016, it became the first commuter rail service completed as part of the 2004 voter-approved FasTracks project. Customers aboard the electric commuter rail train can skip bumper-to-bumper traffic and airport parking costs, all while being conveniently dropped off near the main airport terminal. The service operates at speeds up to 79 mph, faster than light rail’s top speed of 55 mph, for a 37-minute trip to DEN from DUS.
A Line leads in boardings
The Train to the Plane has maintained strong utilization throughout its decade in service. During the COVID-19 pandemic, the A Line led the nation in terms of commuter rail utilization and revenue hours, according to a 2024 report. In January 2026, the most recent month for which data is available, A Line ridership increased 17.7% compared with the same time last year. In 2025, ridership increased by 4.3%, the highest increase among all RTD commuter rail lines. From January 2025 through February 2026, boardings totaled 7,166,178, bringing total ridership close to 60 million since its launch.
"Transportation investments like the A Line continue to attract homebuyers, investors and businesses to Aurora," said Aurora Mayor Mike Coffman. "I join RTD in celebrating this vital connection that has improved multimodal mobility for the entire region."
“There are so many things that can make a trip out of town stressful. The ride to the airport shouldn’t be one of them,” added Denver Mayor Mike Johnston. “For 10 years the A Line has been as consistent as it is convenient and, thanks to RTD’s hard work, I have no doubt that will continue to be the case for decades to come.”
Because timely service is crucial for making travel connections, the A Line’s notable on-time performance averaged 90% overall last year and 91% as recently as March 2026. On-time performance measures how often vehicles arrive at stations according to the posted schedule. Service availability – the percentage of trips that operate as scheduled – reached 97.7% for the A Line in 2025. The combined metrics make the A Line a reliable solution for customers to bridge travel connections to and from the airport.
“I often boast that Denver International Airport has the best direct connection to its downtown core than any other city in the U.S., and I believe that is true,” said DEN CEO and former RTD General Manager and CEO Phil Washington. “For the past decade, the A Line has delivered a reliable, accessible, and convenient connection between downtown Denver and the airport. It has transformed how DEN connects to downtown and how our community connects to the world. This milestone reflects the partnerships, planning, and public trust that made it possible. And, best of all, the A Line was completed ahead of schedule and well under budget.”
For customer ease of access, the A Line departs every 15 minutes from DUS from 6 a.m. to 8 p.m. and 30 minutes during early morning and late evening hours, identical to the service hours when the A Line first launched in April 2016.
Built for safety
The A Line was the first public transit rail line 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, signals an operator to slow or stop the train, and automatically stops a train if needed.
To maintain level boarding in compliance with the Americans with Disabilities Act of 1990, the A Line and all of RTD’s other commuter rail services use a specialized underfloor wheel lathe to precisely grind the steel wheels of the trains. This process ensures train doors consistently align with platform heights for seamless boarding.
A decade in the making
To deliver the A Line, RTD and its concessionaire operator, DTP, entered into the first public-private partnership for transit in the United States. The A Line was the first of three commuter rail lines to open in Denver because of that partnership.
Plans for RTD’s first commuter rail between downtown Denver and DEN began in 1997. RTD conducted an investment study to evaluate recommendations for commuter rail, light rail, and highway development plans. The A Line’s final track was constructed in 2014, followed by testing and safety compliance in 2015 ahead of the A Line’s 2016 debut.
RTD designated the letter “A” to be reserved for the “Airport” commuter rail line almost 30 years ago. Crews for the A Line worked over 7 million hours to fulfill the project, averaging 800 employees a day. Since the line’s 2016 launch, the cost of an Airport Day pass has increased only $1. Today, a $10 Airport Day Pass provides full-day travel for customers who arrive in Denver and want to continue their journey using RTD’s mobility options to reach their next local destinations.
To mark the 10-year anniversary, here are some additional A Line facts:
- Since opening in April 2016, the A Line has logged about 11 million miles transporting customers
- The Train to the Plane marked a critical milestone of serving 50 million customers by July 16, 2024 – a number equal to filling Empower Field more than 657 times and Coors Field more than 992 times
- The A Line’s 79 mph speed is faster than a cheetah
- A Line trains are heavier than light rail trains, weighing 140,000 pounds, and include luggage racks for customers
- At roughly 23 miles from downtown, Denver International Airport is among the farthest major airports from a downtown in the United States; the A Line completes the trip in 37 minutes
Transit to global connections
The A Line remains RTD’s most popular commuter rail line. Since its historic opening in 2016, the service continues to strengthen mobility options and provide reliable service to help millions of Denver-metro customers and visitors make worldwide connections.
Travel tips
To make connections at DUS or any of the Park-n-Rides along the A Line, customers can plan their airport connection using the NextRide trip planning tool.
More tips to make travel easier include:
- Skip the line at ticket vending machines – download the RTD MyRide app and purchase a $10 Day Pass online or use RTD’s new Tap-n-Ride contactless payment. Simply tap a Visa or Mastercard credit, debit, prepaid card, or mobile wallet directly on a validator to pay your fare and ride.
- Sign up for Service Alerts for real-time travel updates
- Contact RTD Customer Care at 303.299.6000 for route or schedule support. Agents are available 6 a.m.–8 p.m. on weekdays, and 9 a.m.–6 p.m. on weekends and holidays.
- To guarantee a pleasant transit experience, follow the RTD Code of Conduct onboard vehicles and while waiting at stations and stops
- Visit RTD’s Safety and Security webpage to learn more about the agency's efforts to bolster personal safety and enhance security across the entire system
Report safety and security concerns 24/7 to RTD Transit Watch by contacting Transit Police in three convenient ways:
- Elert form on RTD website
- Call: 303.299.2911
- Text: 303.434.9100