Facts & Stats: Everything You Should Know About Denver’s Airport Train

A passenger prepares to board an RTD A-Line train at Union Station on January 30. Streetsblog file photo by Andy Bosselman.
A passenger prepares to board an RTD A-Line train at Union Station on January 30. Streetsblog file photo by Andy Bosselman.

Facts & Stats is a new Streetsblog Denver series that looks at walking, biking and transit through the lens of data and statistics.

Correction: This article has been corrected to reflect correct ridership numbers from 2016 and 2017, which shows a steady increase in A-Line ridership, not a decrease. The error was due to incorrect information provided by RTD.  

In this story, we look at the cost, route, ridership numbers, vehicles, station design and other issues related to the Regional Transportation District’s second-newest railroad, the train between Union Station and Denver International Airport.

Of the many data points collected here, a sharp decline in ridership stands out: In 2016, the A-Line carried 35% more passengers during its first eight months of operation than it did in all of 2018.

RTD is the source of information, unless otherwise noted.  

University of Colorado A-Line to DIA


  • 7 million: Boardings in 2018 (6% increase)
  • 6.6 million: Boardings in 2017
  • 4.1 million: Boardings in 2016 (service started April 22)


  • $1.2 billion: Construction cost (Denver Post)
  • $52 million: Cost per mile ($32 million cost per km) (Streetsblog)
  • $62,202: Capital cost per passenger (based on 2018 daily boardings) (Streetsblog)
  • $10.50: Regular adult fare
  • $5 million: Amount the University of Colorado paid to name the line after itself, even though the route does not come near any of its four campuses. (Denver Post)
  • Yes: Voter-approved FasTracks project
A map of RTD's University of Colorado A-Line route.
A map of RTD’s University of Colorado A-Line route.


  • 23 miles (37 km): Length
  • 7: Stations
  • 4,329: Parking spaces at stations along the line with another 4,371 planned


  • 37 minutes: Time it takes to get between Union Station and DIA
  • 15 minutes: Frequency of service 7 days per week
  • 30 minutes: Frequency of service for early morning and late evening trips
  • 97%: On-time performance rate (Denver7)


  • 170: Maximum passengers per car
  • 79 mph: Maximum speed
  • Rolling stock: Hyundai Rotem Silverliner V (Wikipedia)
  • AC electric overhead wire: Vehicle power source
  • Standard: Rail gage
A rendering of the Denver Airport Station by architect Santiago Calatrava. Calatrava abandoned the project in 2011.
A rendering of the Denver Airport Station by architect Santiago Calatrava. Calatrava abandoned the project in 2011.

Station design

  • Denver commissioned Santiago Calatrava, a Spanish architect known for creating stellar bridges and rail stations around the world, to design Denver Airport Station. Calatrava withdrew from the project in 2011, citing a lack of funding and an unrealistic schedule (Denver Post). Gensler completed the project, along with the adjoining Westin hotel (Gensler). Calatrava was one of several high-profile architects whose projects failed to materialize under the leadership of then-mayor John Hickenlooper (Streetsblog).
  • At Union Station, the global architecture firm SOM designed the open-air Train Hall, Light Rail Terminal and 22-gate underground Bus Concourse (SOM).
  • The local firm Tryba Architects oversaw Union Station’s renovation (Tryba Architects).

Commuter vs. light rail

Commuter rail is relatively new to RTD, with its first route, the A-Line to the Denver International Airport, opening in April 2016, and its second, the B-Line from Union Station to Westminster, opening in July of that year.

RTD operates two types of trains. The familiar light rail vehicles, which have run in the city since 1994, and commuter rail vehicles, which are heavier, carry more passengers, can travel at higher speeds and generally go longer distances between stops.

Crossing gate problems

In November, the Federal Railroad Administration threatened to shut down the A-Line over crossing arms that fail to lower and raise at precise times before and after trains cross intersections (CPR), a problem that has existed since the line first opened. RTD employed human flaggers instead. 

The RTD A, B, G and N-Lines are the first newly constructed rail lines in the U.S. to integrate Positive Train Control systems, which use GPS and other technologies to monitor vehicles. The system can slow or stop trains to prevent wrecks — and it triggers the crossing signals.

RTD and its private partner have struggled to get the crossing arms to work properly. In December RTD scrambled to come up with a plan to fix the crossing gate issue by 2020. RTD presented the plan to the FRA that month and FRA allowed the A-Line to continue operating. Soon after, the FRA allowed RTD to stop using flaggers (Denver Post). Earlier this month, RTD showed another sign of progress when it announced that the FRA would stop requiring A-Line trains to blow its horns at every intersection within Denver.

Eagle P3 Public Private Partnership

FasTracks A and G-Lines and first segment of the B-Line are part of a public-private partnership called Eagle P3. The private entity, known as Denver Transit Partners, provided some money to fund the projects in exchange for RTD paying it to run and maintain the lines over 34 years.

DTP and RTD are suing each other over delays, withheld payments, and the cost of paying human flaggers (CPR).

Are their local transportation Facts & Stats you’d like to know? E-mail andy@streetsblog.org.

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  • Great to see these stats. Surprised ridership is declining. One note–something’s wrong with this number…

    $6,2202: Cost per passenger (based on 2018 daily boardings) (Streetsblog)

    • Streetsblog Denver

      Thank you. The number has been corrected to reflect that the cost per passenger is $62,202, not $6,2202

      • TakeFive

        Wait… did you use the capital costs as apposed to the operating costs? That’s kinda of silly. Capital costs are amortized over long periods typically 30 years.

        • Camera_Shy

          ohh, I don’t know…one way to look at it is, for that capital money, every passenger could have been given a new car!

          I am guessing that for feasibility, etc, capital cost can be ignored, but I’d like to know both the operating cost per passenger (per year), as well as the capital cost per passenger (everyone who ever rides it). I’m ignorant that way. Thanks!

          • swtmix


            “for that capital money, every passenger could have been given a new car!”

            And how much would it have cost to expand the roadways to accommodate those new cars? How much would the congestion caused by those new cars have cost drivers in wasted time? How much would the increased heath costs been because of the increase in pollution?

          • Camera_Shy

            Of course the requirement to get a new car would be that one must ditch their existing car, leading to a net zero increase in the number of cars on the road. 🙂

          • Richard Bullington

            Well, if you want to know “capital cost per passenger (everyone who ever rides it)” then dividing by 30 as suggested is GAAP. Beyond 30 years the NPV of money is essentially zero.

            So, it’s $2,073 per passenger for the capital cost.

            You may say “Thank you” now.

          • Camera_Shy


  • EMB

    As an increasingly frequent A-Line rider, I want two things: better bus connections to the stations with shorter wait times, and those overhead heater things that a lot of NJ Transit stations have. If you’re going to or from the airport, you may not be dressed for Denver weather at that moment, and those platforms can be a cold place to wait 15-30 minutes.

    Oh, and signs that actually direct me quickly from one train platform to the other at Union Station, without requiring me to squint to figure out whether that icon’s meant to be a bus or a train or a gondola or possibly a boat. Is the color-coding on those things even consistent? This stuff needs to be labeled for exhausted travelers carrying a week of luggage.

    Still beats getting stuck in one of those twenty-car pileups on Pena Blvd, though.

    • Oohh

      I feel you with heading to the airport in winter… I just tough it out so I don’t have to bring my big winter coat to Los Angeles or Miami, but heaters would be super nice.

      • EMB

        The heaters operate with a button push and timer, so they’re not drawing power when nobody’s there. So useful!

  • LazyReader

    35% decline in ridership in just two years. Because if you’re going to the airport you’ve got luggage, which offers little space on the train to “lug” pardon the pun.

    From downtown to the airport, Supershuttle costs $25 and Uber costs about $35. The airport train is $9, which sounds like a good deal. But Supershuttle and Uber drivers both pay gas taxes that covered virtually all of the costs of I-70 and the other highways to the airport, while train riders paid none of the $1.1 billion construction cost and only a fraction of the operating cost of the airport train.

    The reality is that the Denver airport line would have been a huge waste of money and should never have been built even if it hadn’t had an 89% cost overrun. With that overrun, Denver is basically bankrupting itself so a few people can take a train to the airport; an airport which at $4.8 Billion (2 billion overbudget) the city nearly bankrupted itself building in the first place.

    Moreover, even if you don’t believe driverless cars will have taken all riders from transit by 2030, they seem almost certain to do so well before 2050. Assuming the technology never proliferates at all, by 2040, the light rail will reach the end of it’s useful life without refurbishment.

    • mckillio

      Gas taxes pay about 50% for highways . Riders definitely paid for part of the train construction.

      • LazyReader

        And the rest can be finagled with a modest toll increase.

        RTD is funded with a combination of farebox recovery (20%) and collected sales tax, advertising, grants and interest income revenues (80%) and those are merely operating costs, not maintenance and capital costs and construction was paid for with federal funds to pay for a local project. A fare hike to compensate for low farebox recovery is only going to deter ridership, not accelerate it. Due to overruns that nearly doubled construction costs, RTD is unlikely to finish all of the lines promised to voters in 2004 without another tax increase. Those cost overruns have also harmed bus riders, who — instead of the enhanced bus service promised by RTD — saw service decline from 39 million bus-miles in 2004 to 36 million in 2015, with more cuts expected in the near future. it is likely that, by 2030, most publicly subsidized mass transit outside of New York City will completely disappear and Denver’s multi-billion-dollar rail lines will be running empty or rusting away. Denver’s RTD will inevitably collapse as many transit agencies will in a very short time frame.

        • iBikeCommute

          Colorado is literally mortgaging it’s buildings to pay for highway widening (see SB 267.) Our roads are only viable based on massive subsidies, far more than rail.

          • LazyReader

            Please, in cities and counties all over the nation transit only accounts for less than 5% of all commuters let alone residents but their systems account for nearly half of their transportation budgets. Several states dedicate a hefty share of highway user fees to transit: Connecticut is the leader at 71%; followed by New York at 55, Maryland at 42; DC at 35; Rhode Island at 31; Pennsylvania at 24; Illinois at 17; Virginia at 13; and New Jersey at 11 . Arizona, Georgia,

            Mississippi, Montana, Nebraska, Ohio, Oklahoma, and West Virginia spend none of their gas taxes on transit, while the remaining states are in the single digits. deduct from this the diversions of gas taxes and other highway user fees to mass transit and other non-highway uses, which in 2016 totaled to $33 billion. Highway subsidies total 1.7 cents per passenger mile. Our highways moved over 4.7 Trillion passenger miles in 2016. Our highway system also carried 2 Trillion ton-miles of freight, something transit cannot do.

            In 2016, transit agencies spend $50.5 billion in taxpayer funds carrying 56.5 billion passenger miles, for an average subsidy of 89 cents per passenger mile. That’s 54 times the subsidy to highways if all of the subsidies are counted against passenger miles.

            We don’t need any highway widening. And I’ve said it before highway and transit funding should be limited to expected revenues. The discrepancies in highway funding can be fixed by mild toll increases or implementing mileage based user fees.

          • TakeFive

            Both roads and transit are paid for by ‘subsidies’ ie taxpayers.

            People dependent on roads pay for all road funding while transit is mostly ‘subsidized’ by those who don’t use transit. Transit is very capital intensive since users don’t buy their own (train) cars and buses.

        • TakeFive

          The primary funding for RTD is a six-tenths percent sales tax which covers operating and other costs. It would include maintenance and smaller capital projects as well as some debt service.

          The ~$5.7 billion capital costs for FasTracks are covered primarily by an additional four-tenths percent sales tax. Federal FTA grants were close to 50% of the A, B and G commuter rail lines plus the W light rail line. the R and N lines did not qualify for FTA funding although there may have been some smaller side grants.

      • TakeFive

        Are you referring to fuel taxes covering about 50% of what the Congress appropriates for transportation funding? BTW, that figure also includes the amount mandated for transit – IIRC it’s 15%.

        • Richard Bullington

          Fuel taxes supply LESS than the annual Federal appropriation for highways alone. General fund revenues provide essentially all of the transit grant funds, and about 1/5 of the highway funds which CON-servatives yammer on are “paid for by the users”.

          Well, yes, they ARE paid for by users of roadways (e.g. citizen taxpayers), but not entirely and not just those who buy gasoline and highway diesel.

          • TakeFive

            I’m not aware of those that yammer roads being paid by users if the reference is to fuel taxes. You have a source for that assertion?

            It is true that roads are paid by those who depend on them which is everybody regardless of the specific taxes involved.

          • iBikeCommute

            You keep making the argument that everyone depends on and pays for roads in one way or another. But the obvious missing element is that some people use the roads a whole lot more but don’t pay their share. IE suburban commuters who commute daily on billion dollar highway expansions while urban folks crowd onto the bus.

          • TakeFive

            Not quite sure of your arbitrary definition for ‘fair share’ but I’ll cede the point.

          • Richard Bullington

            You clearly understand that Federal highway expenditures are not paid fully by fuel taxes. However, most CON-servatives are so convinced that they are that they [the CON-servatives not the roads] WIDELY argue that even city streets and county roads are “paid for by fuel taxes”. The fact is that they are 100% paid by property taxes and other municipal and county revenues.

            That was the point I’m making. They’re stupid or liars. Take your choice.

            I don’t dispute the fact that we ALL depend on roads for our sustenance and said so in my original comment.

          • TakeFive

            I’m still waiting for your sources for all this supposed ‘yammering’….

            It’s true that different jurisdictions pay for roads differently whether city, county or state.

          • Richard Bullington

            Since South Broadway doesn’t appear to be a numbered state highway, that grant was probably from general funds.

            So far as the trolls, they’re all over the Seattle Times, The Columbian, and The Oregonian, my “local” papers blathering about how drivers pay for the “the roads”, but bicycles and pedestrians are freeloaders.

            That’s largely true for the Interstate highways, still somewhat true about the Federal Aid Primary roads (e.g. “US Shield” highways), but not true at all about city streets which is where most bicycles are used.

      • Richard Bullington

        It’s higher than 50%; about 70. Still, no new roads get built without a sizable top-up from the General Fund.

        • mckillio

          No, it’s not.

          • Richard Bullington

            It sounds like you are considering both state and Federal taxes, and you may be right about Colorado’s particular ratio. It varies from state to state. At the Federal level, though, the ratio is about 70%.

            In 2016, the last year that Wikipedia shows, “Highway Outlays” were $30 billion, “Mass Transit Outlays” $8 billion and “Receipts from Dedicated Fund” (e.g. Fuel Taxes) were $35 billion. 35/38ths is almost exactly 92%, so I was actually way low in my recollection.

            Congress “topped up” the Trust Fund with a $70 billion contribution from the General Fund in 2016. So it’s not barely solvent but it does certainly run “in the red” every year. Eventually there will have to be another top up. And another. And another.

          • mckillio

            That doesn’t prove what you think it means.

            If you have to pull funds from somewhere else to make it solvent then it’s not really solvent.

          • Richard Bullington

            Look, I agree that general funds are used to build roadways. The particular accounting fiction known as the “Federal Highway Trust Fund” may not be in long-term balance between inflows from its dedicated funding streams and outflows to projects, but somehow the roads keep getting built. And they will continue to be built, regardless of which line item of the Federal Budget needs to be allocated to the process.

            The process may be sped up or slowed down by changes in the inflow of funds, but 80 years of history says “not by very much”.

          • mckillio

            Sure but that doesn’t mean that drivers should be more directly paying for that infrastructure, which would also make them reconsider driving everywhere all the time, reducing the demand for roads.

          • Richard Bullington

            I agree with that fully. But you only HINTED at that very obliquely heretofore. Could a reader “look between the lines” and see your thought? Sure, if that reader was inclined to agree with you.

            If you want to advocate for direct user fees, say so.

    • TakeFive

      Where do you dig up these crazy numbers?

      $4.8 billion was the Budget figure for DIA and today’s replacement cost would be closer to $30 billion. Denver’s MSA is 19th largest yet DEN is the 5th busiest airport in the country.

      Where are you coming up with “89% cost overrun”? My personal calculation for all of Fastracks is about $70 million per mile; commuter rail cost closer to $60 million per mile. According to Yonah Freemark’s latest data: https://www.thetransportpolitic.com/2019/01/08/openings-and-construction-starts-planned-for-2019/

      Among light rail projects, the average U.S. line will cost $339 million per mile to build…

      Essentially today’s costs are 5X what RTD paid to build out FasTracks.

    • swtmix


      Except those numbers were in error. There has actually been an increase of ~70% in ridership over the last two years, 7 million in 2018 vs. 4.1 million in 2016. But I’m sure you’ll try and spin that into something bad.

  • TransitNerdThrowawayAcct

    Where are you getting the RTD ridership data from?

    The numbers they reported to the APTA for all commuter rail (A and B lines) are substantially lower for 2016 (4.3 million) than the ones you stated just for the A line in 2016 (10.8 million): https://www.apta.com/resources/statistics/Documents/Ridership/2016-q4-ridership-APTA.pdf

    Although unlinked passenger trips could be different than how they defined the ridership data they gave you, the APTA shows continuous growth since 2016 in every quarter it has comparison data from (with no new lines added since 2016). Logically, I also have a hard time believing they doubled the length of the A line trains last month in the midst of a ridership decline of 35% from the first year. So something seems off.

    • TakeFive

      I found that curious but hadn’t had the time to check the APTA numbers. What I do know is that for 2018 based on their station data that the A Line is the only line where all stations reported gains in ridership. Unfortunately the same can’t be said for light rail.

    • Streetsblog Denver

      Please see the correction to the story. RTD provided incorrect information.

  • mckillio

    I’ve always wondered why the cars cost so much more than the Philly ones that were delivered around the same time since we required fewer customizations, shorter warranty period and slower speeds .

    • TakeFive

      Interesting; wasn’t aware of that.

  • TakeFive

    I calculate the cost per mile at ~$60.5 million and even that is very impressive. IIRC DTP bid the A and G Line. In any case, although the B Line was a part of the construction project RTD paid for that separately. I did some research waay back where I found that Flour borrowed ~$450 million from Lloyd’s Bank of London which I assumed was their equity portion. It’s complicated.

  • Trump is my president

    Hyundai totem packed up and left Phil adelphia months ago. Building has already been razed.

  • Sarah

    Better check your figures. If you take the 2016 average weekday boardings of 17653, and assume a full year operation, the total would be 6,461,000. Also, check the letter RTD sent to DRCOG May 1, 2017, where they state, “this past year [2016], the rail line has carried nearly 5 million passengers…” The letter is at drcog.org.

    • TakeFive

      Bravo… Well done!

    • Streetsblog Denver

      Please see the correction above. RTD provided incorrect information.


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