RTD Airport Bus • Boulder ↔ Denver International Airport
RTD AB1 Boulder to Denver Airport Bus Schedule, Stops, Fare and Live Tracker
RTD Route AB1 connects Boulder with Denver International Airport (DEN), serving the Broadway corridor, US 36 stations and the airport transit center. It is an airport route, so the fare, boarding location and flight-planning buffer matter as much as the timetable.
This guide converts RTD’s current schedule into an easier rider view with key departures, route timepoints, airport boarding instructions, the $10 Airport Day Pass, live tracking, park-and-ride options and two current stop changes that AB1 passengers should know before leaving.
Boulder to DEN
Select the eastbound AB1 schedule. Current weekday trips use Downtown Boulder, CU/Broadway, 27th Way, Table Mesa, McCaslin and Flatiron timepoints before DEN.
DEN to Boulder
Select the westbound schedule. Reviewed weekend timetables depart Denver Airport Station from Gate 8 and continue to Flatiron, McCaslin, Table Mesa, CU and Downtown Boulder.
Airport fare
A standard trip that begins or ends at Denver International Airport requires RTD’s airport fare product. The Airport Day Pass is currently $10.
Do not use schedule alone
Airport travel is time-sensitive. Check the current schedule, AB1 live tracker and service alerts shortly before leaving.
Two active changes matter now: Table Mesa boarding locations are temporarily relocated during structural repairs, and the Via Varra/Via Lata AB1 stops have also been moved. Details appear below.
AB1 Route: Boulder to Denver International Airport
RTD identifies AB1 as a Boulder / Denver Airport service. Within Boulder, the route uses the Broadway pattern rather than the Canyon/28th pattern used by AB3.
The diagram below simplifies the principal published timepoints. It is a rider orientation graphic, not a street-level navigation map.
Downtown Boulder
Primary Boulder terminal and RTD customer facility.
Broadway / Euclid
University of Colorado area timepoint.
Broadway / 27th Way
Additional Boulder schedule timepoint.
Table Mesa
Important US 36 connection and park-and-ride.
McCaslin
US 36 station serving Louisville/Superior area.
Flatiron
US 36 station before the airport segment.
DEN Airport
Denver Airport Station / Transit Center.
Additional Boulder stops exist between major timetable columns. RTD’s AB1 note identifies Boulder stops including Downtown Boulder Station, Euclid, Baseline, 27th Way, Dartmouth, Table Mesa/39th Street Park-n-Ride, Table Mesa/Tantra and US 36 & Table Mesa Station.
Choose the Correct AB1 Direction
Eastbound — Boulder → DEN
Use this direction when traveling to Denver International Airport. On the reviewed Monday–Friday schedule, the airport timepoint is Denver Airport Station Gate 6. Saturday also shows Gate 6 on the reviewed timetable.
Westbound — DEN → Boulder
Use this direction when leaving the airport for Boulder. The reviewed Saturday and Sunday/Holiday schedules show departure from Denver Airport Station Gate 8.
Airport gate assignments can differ by service day or future service change. Use the day-specific RTD schedule rather than memorizing one gate permanently.
Monday–Friday eastbound
AB1 Weekday Boulder to Denver Airport Times
RTD marks all timetable times as approximate. The board below highlights useful current weekday departure anchors from Downtown Boulder and the corresponding scheduled DEN arrival.
BOULDER DEPARTDEN ARRIVERUN TIME
2:57 AM4:10 AM73 min
4:27 AM5:40 AM73 min
5:27 AM6:40 AM73 min
6:26 AM7:50 AM84 min
9:26 AM10:50 AM84 min
12:26 PM1:50 PM84 min
3:26 PM4:50 PM84 min
6:26 PM7:50 PM84 min
7:27 PM8:45 PM78 min
9:41 PM10:59 PM78 min
11:41 PM12:59 AM78 min
There are additional AB1 trips not displayed in this compact board. Some trips can begin at Table Mesa instead of Downtown Boulder, and several weekday Downtown Boulder departures use Gate 3 instead of Gate 2. Use RTD’s full schedule below for your exact departure.
How One Early AB1 Airport Trip Progresses
This example converts one current Monday–Friday RTD timetable row into a simple stop-by-stop trip.
AB1 Timepoint
Scheduled Time
Rider Use
Downtown Boulder Station Gate 2
2:57 AM
Boulder origin
Broadway / Euclid — University of Colorado
3:06 AM
CU / Broadway boarding
Broadway & 27th Way
3:09 AM
Central Boulder timepoint
US 36 & Table Mesa Station
3:20 AM
Park-n-Ride / connection
US 36 & McCaslin Gate B
3:26 AM
Louisville/Superior area
US 36 & Flatiron Gate A
3:32 AM arrive / 3:33 AM leave
Broomfield-area connection
Denver Airport Station Gate 6
4:10 AM
DEN Transit Center arrival
Current Table Mesa construction changes the physical boarding location. Do not rely solely on the normal gate name shown in a timetable; follow RTD’s temporary boarding instructions.
Saturday + Sunday/Holiday
AB1 Weekend and Holiday Schedule Differences
Saturday Boulder → DEN
The reviewed Saturday eastbound schedule begins with a 3:04 AM Downtown Boulder departure reaching DEN at 4:17 AM. Later departures continue throughout the day.
Sunday/Holiday Boulder → DEN
The reviewed Sunday/Holiday schedule begins with a 3:03 AM Downtown Boulder departure reaching Denver Airport Station at 4:14 AM.
Sunday/Holiday DEN → Boulder
The reviewed westbound schedule begins at DEN at 5:20 AM and includes late-night service. A 12:10 AM airport departure reaches Downtown Boulder at 1:13 AM.
Selected Sunday/Holiday DEN Departures
DEN GATE 8DOWNTOWN BOULDERTRIP
5:20 AM6:28 AM68 min
8:20 AM9:30 AM70 min
9:20 AM10:30 AM70 min
7:50 PM9:02 PM72 min
10:50 PM11:59 PM69 min
12:10 AM1:13 AM63 min
Scheduled trip-time examples
How Long Does AB1 Take From Boulder to DEN?
Current weekday scheduled terminal-to-terminal examples vary by trip. The figures below are derived from the published Downtown Boulder departure and DEN arrival columns; they are schedule times, not guarantees.
2:57 AM
Early morning
73 min
4:27 AM
Early morning
73 min
9:26 AM
Daytime
84 min
11:41 PM
Late evening
78 min
Do not build a flight connection around the scheduled bus arrival alone. Traffic, weather, service disruption, airport walking time, baggage check and security all occur outside the timetable.
Flight connection planner
How Early Should You Take AB1 for a Flight?
Denver International Airport advises passengers to arrive inside DEN at least two hours before their boarding time. That airport recommendation begins when you reach the airport—it is not a recommendation to leave Boulder only two hours before boarding.
1. Boarding time
FLY
Start with the boarding time on your airline itinerary, not just scheduled departure time.
2. DEN buffer
2H+
DEN advises being inside the airport at least two hours before boarding.
3. Transit Center
DEN
Allow time to move from the RTD Transit Center into Jeppesen Terminal.
4. AB1 trip
AB1
Match the scheduled airport arrival to a trip with sufficient margin.
5. Delay margin
+
Add extra time when weather, traffic or missing the bus would jeopardize the flight.
For an important flight, taking the latest mathematically possible AB1 is weak planning. The consequence of missing one bus is much larger than arriving at DEN early.
RTD uses Local and Airport fare levels. A standard-fare trip that originates or ends at Denver International Airport requires an airport fare product.
Airport Day Pass$10.00Standard airport fare product
Valid all service day throughout the RTD system, including travel to or from DEN.
Standard Day Pass$5.50Non-airport standard fare
A standard Day Pass by itself does not cover a trip to or from DEN. RTD lists a $4.50 airport upgrade.
3-Hour Pass$2.75Standard local fare
RTD lists a $7.25 airport upgrade from a standard 3-Hour Pass.
Monthly Pass$88Airport included
RTD’s standard Monthly Pass is valid throughout the system and includes travel to and from the airport.
Discount fares
RTD discount fares apply to eligible seniors 65+, riders with disabilities, Medicare recipients and eligible LiVE customers. Discount fare products include airport travel at no additional airport charge.
Youth
RTD currently allows riders age 19 and younger to ride all RTD services free with required proof of eligibility.
Active-duty military
Active-duty U.S. military members currently ride RTD services free with proof of eligibility.
Ways to Pay on AB1
Tap-n-Ride
Tap an eligible contactless credit/debit card or supported mobile wallet when boarding.
MyRide
RTD’s MyRide app/card supports account-based payment and fare capping.
Cash
Cash is accepted on RTD buses. Have exact change because the operator does not make change.
Airport upgrade
Standard 3-Hour or Day Pass riders can pay the required airport upgrade under RTD’s current fare rules.
Partial AB1 trips can be different: RTD says some partial journeys on Airport routes can qualify for a non-airport fare. Tell the bus operator before paying when your trip does not begin or end at DEN and you believe the lower fare applies.
RTD buses pick up and drop off passengers at the DEN Transit Center. Denver International Airport says the Transit Center is reached from the south end of Jeppesen Terminal by exiting through the glass doors and taking an escalator or elevator to ground level.
Arriving on AB1
Exit the bus at Denver Airport Station and follow DEN signs from the Transit Center toward Jeppesen Terminal, airline ticketing, baggage services or security.
Leaving DEN for Boulder
Follow airport signs to the Transit Center, then verify AB1, the current boarding gate and the westbound departure time before waiting.
Luggage
DEN states that RTD bus drivers help passengers load and unload luggage. Keep essential documents and valuables with you rather than inside unattended baggage.
Current DEN construction: the airport is presently reporting that the South Level 6 terminal bridge and connected escalator are closed until mid-November. Follow current airport wayfinding because pedestrian circulation can change during construction.
RTD information at DEN
DEN lists an RTD information booth at the Transit Center. Published booth hours are Monday–Friday, 8:00 AM–4:30 PM.
Ground Transportation Information Counter
DEN lists its Ground Transportation Information Counter on Level 5 of Jeppesen Terminal, with published daily hours of 6:00 AM–11:30 PM.
These changes were displayed by RTD when this page was reviewed on August 12, 2026. Because both are active “until further notice,” confirm them again before your trip.
UNTIL FURTHER NOTICETable Mesa Station Construction
RTD began structural repair work at the Table Mesa Park-n-Ride on March 23, 2026. Gates B and C in front of the parking garage are temporarily closed.
Arriving AB / FF riders: RTD says passengers deboard along Table Mesa Drive across from the Park-n-Ride.
Eastbound AB1: board at the south-ramp boarding plaza on the south side of US 36. RTD directs customers through Level 4 of the garage and the pedestrian bridge to reach that plaza.
Westbound AB1: board at Gate E along Table Mesa Drive.
RTD currently estimates the construction project will continue through September 2027.
STOP MOVEVia Varra / Via Lata Stops Relocated
RTD moved both AB1 stops at Via Varra Road & Via Lata Drive because of safety concerns.
Eastbound affected stop: #34785.
Westbound affected stop: #34786.
The relocated stops are just south of the Terracina Luxury Apartments driveway.
Alternate eastbound stop: 13600 Block Via Varra #35482.
Alternate westbound stop: 13500 Block Via Varra #35483.
Do not use an old screenshot of Table Mesa or Via Varra as your final boarding guide. Temporary stops are exactly the kind of detail that can change while a saved timetable remains on your phone.
Driving to a station can make AB1 practical for riders who do not live within walking distance of a Boulder stop. Parking rules and fees can change, so verify the facility before leaving a vehicle for an airport trip.
Tantra Dr / Table Mesa
500 Tantra Dr
Boulder, CO
RTD lists paid parking
105 parking spaces
Bike racks: Yes
Bike lockers: Yes
AB1 listed among bus routes
US 36 / McCaslin East Side
1164 Dillon Rd
Louisville, CO
RTD lists paid parking
466 parking spaces
Bike racks: Yes
Bike lockers: Yes
AB1 listed among bus routes
US 36 / McCaslin West Side
305 Center Dr
Superior, CO
RTD lists paid parking
466 parking spaces
Bike racks: Yes
Bike lockers: Yes
AB1 listed among bus routes
Airport parking strategy: “paid parking” does not automatically mean every vehicle can remain for any number of days. Review RTD’s current parking rules before leaving a car during a multi-day trip.
AB1 Live Bus Tracker: What to Check Before Leaving
RTD Next Ride is the appropriate real-time tool for Route AB1. Use it after confirming your scheduled trip rather than replacing the timetable with a live map.
1. Scheduled trip
Confirm that an AB1 trip is supposed to operate on your service day.
2. Vehicle prediction
Look for a live or predicted arrival at the correct stop.
3. Route alert
Check Table Mesa, Via Varra and any new detour notices.
4. Flight status
For airport travel, also confirm that your airline flight remains on schedule.
No vehicle on the map does not automatically mean AB1 is canceled. GPS reporting can be unavailable before a trip starts or during a tracking problem. Compare the tracker with the official timetable and alerts.
View the Current RTD AB1 Timetable and PDF Options
RTD’s current AB1 schedule page provides both a PDF Map and PDF Timetable control. Those PDFs are generated by RTD rather than exposed as a reliable permanent file URL, so this page does not invent or hard-code a guessed PDF address.
The official live schedule is embedded below when RTD permits iframe display. If the viewer is blocked, use the buttons immediately underneath it.
PDF accessibility: RTD notes that generated PDF schedules may not be fully screen-reader accessible and directs riders who need an accessible timetable to use the web schedule.
How to Read the AB1 Timetable Without Missing Your Bus
Select AB1, not simply “AB.”
RTD groups AB1, AB2 and AB3 under Boulder / Denver Airport service, but their Boulder stop patterns are not identical.
Choose eastbound or westbound.
Eastbound generally means toward DEN; westbound means toward Boulder.
Select the service day.
Monday–Friday, Saturday and Sunday/Holiday schedules have different departure patterns.
Find the nearest major timepoint.
Printed schedule columns do not represent every stop along the route.
Understand the dash symbol.
A dash means that particular trip does not serve that printed timepoint.
Check temporary boarding instructions.
Table Mesa is the current example where the normal schedule label and physical boarding location differ.
Avoid the wrong airport bus
AB1 vs AB2 vs AB3: They Are Not the Same Boulder Route
RTD groups AB1, AB2 and AB3 as Boulder / Denver Airport services. That does not make the Boulder portions interchangeable.
AB1Broadway Pattern
RTD’s timetable note identifies AB1 Boulder stops through the Broadway pattern, including Downtown Boulder, Euclid, Baseline, 27th Way, Dartmouth and Table Mesa-area stops.
AB2Separate RTD Airport Service
AB2 is another Boulder / Denver Airport option shown by RTD. Open its own schedule before using it because its stop pattern and departure times can differ from AB1.
AB3Canyon / 28th Pattern
RTD’s timetable note identifies AB3 through Canyon/28th-area Boulder stops including McGuckin, 28th/Arapahoe, Taft and Colorado before Table Mesa.
If Google Maps or another trip planner suggests an AB2 or AB3 departure, do not apply the AB1 stop list to it. Open the exact route recommended for your journey.
How to Ride AB1 if You Have Never Used RTD Before
Identify the stop number.
RTD bus stops use red-and-white signs showing the routes and a stop number.
Confirm AB1 on the vehicle.
Do not board solely because the destination says airport; check the route identifier too.
Have payment ready.
Tap the appropriate contactless/MyRide fare or prepare exact cash before boarding.
Store luggage safely.
Follow operator instructions and keep aisles and accessible areas clear.
Track your progress.
Airport passengers can use the major US 36 stations as useful trip landmarks.
Request your stop when needed.
RTD advises signaling roughly one block before the stop using the cord, strip or stop-request button available on the vehicle.
AB1 Wheelchair Accessibility and Mobility Planning
Denver International Airport states that RTD buses and trains serving DEN are wheelchair accessible. Riders should still distinguish an accessible vehicle from the condition of an individual sidewalk or temporary boarding location.
Accessible vehicle
Ask the operator for the ramp, lift or mobility-device assistance needed for boarding.
Table Mesa construction
The temporary eastbound boarding arrangement involves the station garage, Level 4 and the pedestrian bridge. Riders who need assistance should review RTD’s current construction information before arriving.
DEN Transit Center
DEN describes elevator access between Jeppesen Terminal and the ground-level Transit Center.
Need specialized trip assistance? RTD Customer Care can help with route planning, and Access-a-Ride is RTD’s separate ADA complementary paratransit service for eligible riders.
Luggage, Bikes and Airport Travel on AB1
Suitcases
DEN says RTD bus drivers help passengers load and unload luggage. Be ready at your stop so baggage handling does not make you miss boarding.
Valuables
Keep passports, identification, phones, wallets, medication and travel documents with you rather than in baggage that is harder to monitor.
Bicycles
RTD lists bike racks and lockers at several AB1 Park-n-Rides. Check current vehicle bike-capacity rules before depending on bicycle space for an airport connection.
RTD Sunday/Holiday schedule
AB1 Holiday Schedule
RTD states that buses follow the Sunday/Holiday timetable on these six holidays:
New Year’s Day
Use the AB1 Sunday/Holiday schedule.
Memorial Day
Use the AB1 Sunday/Holiday schedule.
Independence Day
Use the AB1 Sunday/Holiday schedule.
Labor Day
Use the AB1 Sunday/Holiday schedule.
Thanksgiving Day
Use the AB1 Sunday/Holiday schedule.
Christmas Day
Use the AB1 Sunday/Holiday schedule.
Flight-day reminder: airlines still operate on holidays even when the transit schedule changes. Check the correct RTD service day before leaving for DEN.
If You Miss AB1 or the Bus Is Delayed
You missed the Boulder departure
Immediately check the next AB1, AB2 or another RTD airport option in the official trip planner. Do not assume another airport route uses your current stop.
No live prediction appears
Compare Next Ride with the timetable and alerts. A missing GPS prediction is not identical to a canceled trip.
Table Mesa stop looks closed
Follow the current AB/FF temporary boarding instructions rather than waiting at closed Gates B or C.
Your flight margin is disappearing
Re-evaluate immediately. Saving the fare is not worth missing a flight when another safe transportation option provides a more reliable arrival margin.
AB1 Airport Trip Checklist
Confirm AB1 instead of AB2 or AB3.
Select eastbound or westbound.
Check weekday, Saturday or Sunday/Holiday schedule.
Verify your current stop or station gate.
Review Table Mesa construction if using that station.
Review Via Varra relocation if using that area.
Open RTD Next Ride shortly before departure.
Confirm the $10 airport fare or your eligible fare product.
Have MyRide, contactless payment or exact cash ready.
Check your airline’s boarding time and flight status.
Allow DEN’s recommended airport-arrival buffer.
Keep travel documents and valuables accessible.
Boulder / Longmont lost property
What to Do if You Leave Something on AB1
RTD says items found on Boulder/Longmont routes are sent to Downtown Boulder Station rather than the Denver Civic Center lost-and-found location.
Downtown Boulder Station
1800 14th Street
Boulder, CO 80302
Published pickup hours:
Monday–Friday
8:00 AM–5:00 PM
When to check
RTD says found items are normally available after 1:00 PM on the following business day. Items are generally retained for at least seven days before disposal or donation.
Call before visiting: RTD Lost & Found uses 303-299-6000, option 3.
Record Route AB1.
Include direction, boarding location and where you exited.
Record the approximate time.
The scheduled trip and time can help identify the correct vehicle.
Describe the item precisely.
Include color, brand and identifying characteristics.
Protect sensitive accounts immediately.
Lock payment cards or devices instead of waiting for the lost-and-found process.
Denver International Airport lists the Ground Transportation Information Counter on Level 5 of Jeppesen Terminal.
When reporting an AB1 problem, provide useful details: route AB1, direction, stop number, boarding location, date, approximate time and vehicle number when visible.
Official-source research record
Official Sources Used for This AB1 Guide
RTD AB1 Schedule
Current timetable, direction controls, major timepoints, airport gates, weekend/holiday schedules and generated PDF controls.
Denver International Airport
DEN Transit Center access, airport bus location, luggage assistance, accessibility and airport transportation information.
Route, schedule, fare and alert review: August 12, 2026
Independent-site disclosure: busschedule.us does not operate RTD buses, control AB1 schedules, sell RTD fares, manage DEN gates or guarantee arrival times. For a travel decision, use the current RTD schedule and live service information.
Frequently Asked Questions About the AB1 Bus
What is RTD Route AB1?
AB1 is an RTD airport bus service connecting Boulder and Denver International Airport. Within Boulder, RTD identifies AB1 as the Broadway-pattern airport route.
How much is the AB1 bus to Denver Airport?
RTD’s standard Airport Day Pass is currently $10 and is valid all service day across the RTD system, including the airport. Eligible discount fares include airport travel under RTD’s current rules.
Where does AB1 leave from in Boulder?
Downtown Boulder Station is a principal AB1 terminal. RTD also lists Boulder stops along the Broadway pattern including Euclid, Baseline, 27th Way, Dartmouth and Table Mesa-area stops.
Does AB1 stop at the University of Colorado?
The official AB1 timetable includes Broadway–Euclid / University of Colorado as a major schedule timepoint.
Does AB1 stop at Table Mesa?
Yes. AB1 serves the Table Mesa area, but current structural repair work has temporarily changed boarding and deboarding locations. Check the active RTD alert before travel.
How long does AB1 take from Boulder to DEN?
Current weekday Downtown Boulder-to-DEN timetable examples range from about 73 to 84 minutes for the trips reviewed on this page. Actual travel can be longer during disruptions or traffic.
What time is the first AB1 from Boulder to DEN?
The current reviewed Monday–Friday eastbound schedule shows a 2:57 AM Downtown Boulder departure reaching DEN at 4:10 AM. Saturday begins at 3:04 AM in the reviewed schedule, while Sunday/Holiday begins at 3:03 AM. Recheck the current timetable before relying on an early flight connection.
Where do I catch AB1 at Denver Airport?
RTD buses use Denver Airport Station at the DEN Transit Center. The reviewed Saturday and Sunday/Holiday westbound AB1 schedules show Gate 8, but riders should verify the gate for their exact service day.
Can I pay cash on AB1?
Yes. RTD accepts cash on buses, but the driver does not make change, so have the exact required fare ready.
Can I use a contactless bank card on AB1?
RTD offers Tap-n-Ride using eligible contactless credit or debit cards and supported mobile wallets. The same card or device should be used consistently for fare-capping purposes.
Is AB1 wheelchair accessible?
Denver International Airport states that RTD buses and trains serving DEN are wheelchair accessible. Temporary stop conditions can still affect how easily an individual boarding location can be used.
Is AB1 the same as AB2 or AB3?
No. They are all RTD Boulder / Denver Airport services, but their Boulder stop patterns and schedules differ. AB1 follows the Broadway pattern, while RTD identifies AB3 through a Canyon/28th pattern.
Does AB1 run on holidays?
RTD buses operate a Sunday/Holiday schedule on New Year’s Day, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.
How can I track AB1 in real time?
Use RTD Next Ride for Route AB1. Check the live tracker together with the official schedule and active service alerts.
What happens if I leave luggage or another item on AB1?
RTD says lost items from Boulder/Longmont routes are sent to Downtown Boulder Station. Call RTD Lost & Found at 303-299-6000, option 3, before visiting.
