Getting Around Boulder
Boulder and Denver share a common mass transit system called RTD, which serves both the city and the wider Denver region. For visitors, that shared network is the backbone of car-free travel: it links Boulder's downtown and campus with Denver, Denver International Airport, and a string of neighbouring towns. Many locals also simply ride bicycles around the downtown, since most of the city sights sit close together.
Rail, Metro and Trams
Boulder itself has no rail, metro or tram network for visitors to use. The nearest and most accessible train station is in Denver, where you can board Amtrak's California Zephyr and the seasonal Ski Train to Winter Park. There is supposedly an Amtrak throughway bus service from Denver to Boulder, but it is made redundant by the more frequent and cheaper Flatiron Flyer bus. In practice, visitors treat Denver Union Station as the regional rail hub and reach it by bus.
Buses and Public Transport
RTD runs multiple services to and around Boulder, and nearly all RTD buses carry bike racks, so you can combine riding and transit easily. The main services a visitor is likely to use are:
- Flatiron Flyer — the main commuter service in and out of Boulder, running at least every 15 minutes on safe, comfortable buses. It is the practical link to Denver Union Station, where you can connect to other Bustang routes across the state as well as intercity companies such as Greyhound.
- AB — a direct connection between Boulder and Denver International Airport via E470.
- BOLT — a commuter service between Longmont and Boulder, with a stop in Niwot.
- JUMP, 225 and DASH — three routes that run parallel to one another, heading east to Erie, Lafayette and Louisville respectively.
- GS — a direct commuter bus between Boulder and Golden, though it runs very infrequently.
- NB — a semi-seasonal shuttle running only to Nederland in summer and all the way to the Eldora ski resort in winter.
- Flex (Transfort) — Fort Collins' transit provider offers this service to Boulder in three variations; only the F3X goes all the way, making express stops in Longmont and Loveland.
- Bustang — Colorado's state-funded intercity bus service. Its summer seasonal route between Denver and Estes Park stops in Boulder and Lyons, and is the only way to see Rocky Mountain National Park without a car, short of backpacking in.
Locals often use the "Skyride" RTD bus to get to and from the airport, which is described as greener and easier than driving.
Taxis and Ride-Hailing
The source material does not describe taxi or ride-hailing services in Boulder, so visitors should plan around the RTD bus network, cycling and walking rather than assuming a hail-and-ride option.
Walkability and Cycling
Downtown Boulder is compact and well suited to walking: most of the city sights are within a couple of miles of one another, and plenty of locals get around the downtown on bicycles. Bike sharing is available through Boulder B-Cycle, which has stations downtown and near campus and offers unlimited rides under 30 minutes, priced at $8 per 24 hours or $20 per 7 days. For longer trips, Boulder is connected to downtown Denver by the US 36 Bikeway and to Longmont by the LOBO trail.
Driving and Parking
If you do drive around town, expect heavy traffic on the main thoroughfares, plenty of pedestrians and cyclists, and somewhat tight parking downtown. Several city-owned garages are tucked behind the buildings downtown; look for the large green "P" signs outside their entrance ramps, since they don't look like parking garages from the outside. Parking in the university area can lead to expensive tickets. Boulder's police are vigilant about drunk driving, so leave the car behind if you've been enjoying local microbrews. Watch for school zones — when the yellow lights are flashing, slow to 20 mph — and note that many main streetlights have cameras that can capture you running the tail end of a yellow light, with tickets arriving by mail.
Getting from the Airport into Boulder
Denver International Airport (DIA) is the nearest and most practical airport for Boulder. There are two main ways in by transit: take the AB bus, which runs directly from Boulder to DIA via E470, or combine the Flatiron Flyer with the A Line. The Flatiron Flyer is the more frequent option for reaching Denver Union Station, from which you can connect onward.
Getting to Boulder from Denver
Boulder sits roughly 30 miles from downtown Denver, reachable via I-25 and highway 36, also known as the Boulder Turnpike. Both the drive and the bus ride on US 36 offer spectacular, scenic views of the Flatirons, Boulder's iconic natural landmark. The Flatiron Flyer is the recommended transit option for this trip, running at least every 15 minutes and costing less than the alternative Amtrak throughway bus.