GDT > RTD Rider’s Guide > Routes > Route AB – Boulder / Denver Airport
SkyRide Routes AB1 and AB2, ‘Boulder / Denver Airport’, run from to Downtown Boulder Station and Boulder Junction to Denver Airport via US 36, Flatiron, the Northwest Parkway and E-470.
Map & Schedule
Route AB1 operates 7 days a week. Frequency is generally 60 minutes at all times, although an extra trip is offered in the early afternoon to serve a common end of shift time for airport employees.
Route AB2 operates on weekdays only providing peak period service at 60 minute frequency via 28th Street in Boulder to Boulder Junction, which reopened in August 2025. The route was suspended due to the Covid-19 pandemic and proposed to be reinstated in the System Optimization Plan, this was partially done in January 2025 and August 2025.
Route AB3 operates on Saturdays only providing peak period service at 60 minute frequency via 28th Street in Boulder to Downtown boulder Station. The route was created in August 2025.
Vehicles Used
The route is operated by RTD using MCI D4500CT over-the-road coaches from Boulder Garage.
Ridership
| Year | Route AB | Route AB1 | Route AB2 | Total |
| 2018 | – | 598,000 | 62,000 | 660,000 |
| 2019 | 2,000 | 619,000 | 111,000 | 732,000 |
| 2020 | – | 288,000 | 28,000 | 316,000 |
| 2021 | – | 409,000 | – | 409,000 |
| 2022 | – | 522,000 | – | 522,000 |
| 2023 | – | 601,000 | – | 601,000 |
| 2024 | – | 641,000 | – | 641,000 |
Note: Figures from 2021 include former Route AB and AB2 riders.
Current Issues
None reported.
Future Plans
The System Optimization Plan proposes to reinstate route AB2 service in the peak periods, 7 days a week.