Bus rapid transit in the Denver metropolitan area

The Denver metropolitan area currently has one bus rapid transit service, the Flatiron Flyer, with three more under construction.

Flatiron Flyer

Flatiron Flyer
Flatiron Flyer bus on Wewatta Street in Denver
Overview
Operator	Regional Transportation District
Garage	Platte Division, Boulder Division
Vehicle	56 MCI D4500CL coaches
Began service	January 3, 2016;9 years ago (2016-01-03)
Predecessors	BF, BMX, BV, BX, HX, S, T, 86X, 90L
Route
Locale	Denver metropolitan area
Communities served	Aurora, Boulder, Broomfield, Denver, Superior, Westminster
Start	Denver Union Station, Civic Center Station, Anschutz Medical Campus
Via	U.S. Route 36
End	Downtown Boulder Station, Boulder Junction Station
Service
Frequency	Peak: 10 minutes Off-peak: 30 minutes [1]
Weekend frequency	Saturday: 15 minutes Sunday: 30 minutes
Ridership	1,219,000 (FY2023, annual) [2]
Route map Legend Boulder Junction 4, 6 Downtown Boulder 1, 2, 5 Boulder local stops Boulder local stops Pearl Pkwy & 49th Central Ave & Flatiron Pkwy E 28th & Walnut/ 28th & Canyon (CU) Arapahoe & 55th Arapahoe & 48th Arapahoe & 38th/ Arapahoe & Marine Arapahoe & 30th 28th & Arapahoe 4, 6 28th & College/ 28th & Colorado 4, 6 Broadway & Euclid (CU) Broadway & Baseline Table Mesa & 39th US 36 US 36 & Table Mesa 1, 2, 4, 5, 6 US 36 & McCaslin 1, 2, 4, 5, 6 US 36 & Flatiron 1 US 36 & Broomfield 1, 3, 4, 5, 6 US 36 & Church Ranch 1, 3 US 36 & Sheridan 1, 3, 4, 5, 6, 7 Aurora local stops Aurora local stops Fitzsimmons Pkwy & Montview Colfax & Fitzsimmons Pkwy Colfax & Wheeling Colfax & Vaughn Aurora Ct & 16th 17th Pl & Aurora Ct Aurora Ct & 17th Ave Aurora Ct & 16th Ave Quentin & 16th Ave Quentin & 17th Ave Quentin & 19th Ave Anschutz Medical Campus 5 Denver local stops Denver local stops 20th & Larimer/19th & Market 18th & California/ 19th & Stout 18th & Welton/ Broadway & Glenarm Civic Center Station 4, 7 Union Station 1, 2, 3, 6 Key FF1 FF2 FF3 FF4 [a] FF5 FF6 [a] FF7 [a] Two lines Multiple lines This diagram: view talk edit ← {{{previous_line}}}  {{{system_nav}}}  {{{next_line}}} →

Flatiron Flyer is an 18-mile (29 km) express bus system between Denver, Aurora, and Boulder, Colorado, traveling along U.S. Route 36. Different levels of service are available, including a non-stop from Boulder to Union Station in high-occupancy toll lanes (HOT lanes), and all-stop, which serves six park-and-rides along U.S. Route 36 in normal highway lanes. The line branches out to different destinations in Denver, Aurora and Boulder. The Regional Transportation District operates the line, opened on January 3, 2016.

The ITDP classified the system as "not bus rapid transit" (BRT), due to the use of lanes shared with private cars along US 36, lack of street level boarding/alighting and the lack of an off-board fare system. The system has been criticized as an example of bus rapid transit creep because RTD and the Colorado DOT ^[3] claim the Flatiron Flyer is bus rapid transit despite it lacking most BRT features. ^[4]

Route

A branching route system is employed, with the backbone of the system being the HOT lanes along U.S. Route 36. ^[5] High-occupancy vehicles and buses travel free in the HOT lanes, while single-occupancy vehicles must pay between $1.25 to $7.60, depending on time of day, or up to $13.68 without an electronic toll collection pass. ^[6] The HOT lane will be managed to ensure that traffic will flow at 50 to 55 miles per hour (80 to 89 km/h). ^[7] Union Station and Civic Center in Denver and Anschutz Medical Campus in Aurora serve as the southern termini, while Downtown Boulder and Boulder Junction are the northern termini.

Given that the Flatiron Flyer travels with other vehicles in the HOT lanes, the lack of street level boarding and alighting, and the lack of an off-board fare system, it has been classified as "Not BRT" by the Institute for Transportation and Development Policy, which promotes construction of BRT systems. ^[8] This new system has been criticized as bus rapid transit creep.The original FasTracks plan approved by voters indicated that center-line BRT stations would be created to avoid buses exiting the highway and sitting at traffic intersections. ^[9] However, this plan was shelved and three of the stops were redesigned to use slip ramps instead.

Subsequent plans to give buses the right to use the shoulder as a travel lane during traffic jams required a change in law; RTD buses got the go-ahead in March 2016, and took effect in April of that year. ^{[10] [11]}

Stops

There are six park-and-rides along U.S. Route 36 from Denver to Boulder, which have been dubbed "stations", that will be served by Flatiron Flyer: ^[12]

• US 36 – Sheridan (1,310 parking spaces)
• US 36 – Church Ranch (394 parking spaces)
• US 36 – Broomfield (pedestrian bridge, 940 parking spaces)
• US 36 – Flatiron (264 parking spaces)
• US 36 – McCaslin (pedestrian bridge, 466 parking spaces)
• US 36 – Table Mesa (pedestrian bridge, 824 parking spaces)

These stops have ticket vending machines, and passenger information systems.

Service

Express service between Boulder and Denver is expected to take slightly under an hour, which is about 10 to 15 minutes faster than current bus routes. ^[7]

There was some opposition to the proposed consolidation of routes between Boulder and Denver. Buses along the most popular routes would come more frequently under the new service plan, but Boulder Junction would receive less service. ^[13]

Service plan

Headways along different routes vary based on the time of day. ^[14]

Route	Routing	Eastbound to Denver			Westbound to Boulder			Notes
		AM peak	Midday	PM peak	AM peak	Midday	PM peak
FF1	Downtown Boulder – Union Station	15 min	15 min	15 min	15 min	15 min	15 min	[15]
FF2	Downtown Boulder – Union Station Express	2 trips	–	1 trip	2 trips	–	1 trip	[16]
FF3	US 36 & Broomfield – Union Station	–	–	–	–	–	–	Runs 2 trips per week in each direction (Sunday evenings only) [17]
FF4	Boulder Junction – Civic Center	15 min	–	15 min	15 min	–	15 min	Currently suspended
FF5	Downtown Boulder – Anschutz Medical Center	5 trips	–	2 trips	1 trip	–	3 trips	[18]
FF6	Boulder Junction – Union Station	–	–	3 trips	3 trips	–	–	Currently suspended
FF7	US36 & Sheridan – Civic Center	20 min	–	–	–	–	20 min	Currently suspended

History

Flatiron Flyer was constructed as part of the FasTracks program, which built six new commuter rail, light rail, and bus rapid transit lines in the Denver metropolitan area. ^[19]

Widening U.S. Route 36 to accommodate the bus line was a joint project between the Colorado Department of Transportation and RTD, termed the US 36 Express Lanes Project. The highway was widened by 40 feet (12 m) in each direction, adding a high-occupancy vehicle lane, which the buses will use when possible. To accommodate the lanes, several bridges were replaced and shoulders were widened. As part of the multi-modal commitment, a concrete trail was added between Westminster and Table Mesa, the U.S. 36 Bikeway. ^[20] The project was completed in two phases. The first phase, from Federal Boulevard to 88th Street in Louisville/Superior, ^[21] took three years (July 2012 - July 2015) and cost $317 million. Phase 2 of the project extended the HOT lanes from 88th Street to Table Mesa Drive in Boulder through a public–private partnership; ^[22] it opened on January 3, 2016, with toll collection starting in March of that year. ^[23]

Fleet

In June 2015, RTD announced the $35 million purchase of 59 MCI D-Series motorcoaches, each of these 45-foot (14 m) buses can carry up to 57 passengers. ^[24]

In August 2015, the University of Colorado (CU) paid $5 million over five years to place advertisements on Flatiron Flyer buses, with an option to extend for another five years. The deal also included the naming rights for the DIA rail line, dubbed the University of Colorado A Line. ^{[25] [26]}

Criticism

Originally, the voter-approved plan called for a 41-mile (66 km) high-capacity commuter rail line running from Denver Union Station to Longmont, passing through North Denver, Adams County, Westminster, Broomfield, Louisville and Boulder. ^[27] RTD opened the first segment of this rail line, the B Line, from Union Station to Westminster Station — near 71st Ave. and Federal Blvd. — in July 2016. ^[28] The completion of the originally-planned route from Westminster to Longmont has been delayed until 2044 due to lower tax revenues and higher costs than expected. ^{[29] [30]} RTD introduced "Flatiron Flyer" as its brand for the US 36 Bus Rapid Transit component of FasTracks, serving travelers between Denver and Boulder. ^{[31] [32]} As an interim measure until Northwest Rail can be completed, RTD committed to study high-speed bus options in other parts of the corridor as well as the possibility of extending the North Metro Line to Longmont. ^[33] The consolidation of current express service between Denver and Boulder into the Flatiron Flyer system attracted criticism from Boulder residents, since increased frequencies would be balanced with some service cuts. ^{[34] [35] [36]} Additionally, the ITDP classifies the system as "not bus rapid transit", due to the use of lanes shared with private cars along US 36. ^[8]

LYNX

LYNX is a planned Bus Rapid Transit system in Denver and its inner suburbs. One line, on East Colfax Avenue, is under construction, and is planned to open in 2027, while others on Federal and Colorado Boulevard are in various stages of planing, and are planned to open by 2030. ^{[37] [38]}

Diagonal Flyer

The Diagonal Flyer is an under-construction express bus line in Boulder and Longmont, Colorado. Buses will run in two patterns, the DF1, which will run all-week, for most of the day between Longmont and Downtown Boulder Station, mirroring the route of, but doubling service on what is now the BOLT route, and the DF2, which will run on weekday peak hours only between Longmont and Boulder Junction, mirroring the alignment and service levels of the former route J.

Construction started on September 23, 2024, and service is projected to start in May of 2027. ^[39]

CO-7 BRT

BRT on State Highway 7, between Boulder and Brighton, is planned to open in 2027, with a "starter service" in 2026. ^[40]

References

1. Temporarily suspended

1. "RTD – Proposed Service Changes".
2. "RIDERSHIP (BOARDINGS) BY MONTH, YEAR AND MODE" (PDF). RTD. Archived (PDF) from the original on February 14, 2025. Retrieved March 4, 2025.
3. "Where is CDOT building BRT?" (PDF). Colorado Department of Transportation.
4. "Flatiron Flyer Facts".
5. Whaley, Monte (September 30, 2014). "U.S. 36 buses to arrive next October". The Denver Post. Retrieved August 21, 2015.
6. Aguilar, John (May 8, 2015). "Colorado's new express lanes, passes will take getting used to". The Denver Post. Retrieved 30 May 2015.
7. Heffel, Nathan (June 21, 2015). "Beyond The Tolls: U.S. 36 Brings Buses, Bikes Into The Mix". Colorado Public Radio. Retrieved August 21, 2015.
8. "U.S. 36 bus transit plan is not what it seems, group says". Denverpost.com. 25 January 2015. Retrieved 2015-04-17.
9. "2004 Fastracks Plans [page 1-19]" (PDF).
10. "U.S. 36 Flatiron Flyer can drive on shoulders". The Denver Post. 2016-04-29. Retrieved 2020-01-24.
11. Proctor, Cathy (2016-04-29). "RTD's Denver-Boulder buses will use shoulders to bypass jams". www.bizjournals.com. Retrieved 2020-01-24.
12. "Introducing the Flatiron Flyer" (PDF). RTD. Retrieved August 26, 2015.
13. Antonacci, Karen (March 16, 2015). "RTD solicits public comments on proposed Denver-Boulder route". Boulder Daily Camera. Retrieved August 21, 2015.
14. "Flatiron Flyer". RTD. Archived from the original on November 1, 2017. Retrieved November 13, 2017.
15. "FF1 Schedule". RTD Denver. Retrieved 16 April 2025.
16. "FF2 Schedule". RTD Denver. Retrieved 16 April 2025.
17. "FF3 Schedule". RTD Denver. Retrieved 16 April 2025.
18. "FF5 Schedule". RTD Denver. Retrieved 16 April 2025.
19. Burness, Alex (September 10, 2014). "RTD's 'Flatiron Flyer' Boulder-Denver rapid-transit bus to debut in 2016". Boulder Daily Camera. Retrieved August 21, 2015.
20. Reimers, Ashley (2015-07-07). "Flatiron Flyer provides quicker ride for Westminster commuters". Colorado Community Media. Retrieved 2020-01-24.
21. Whaley, Monte (June 22, 2015). "U.S. 36 first phase gets send off from local, state, fed officials". The Denver Post. Retrieved August 21, 2015.
22. "US 36 Express Lane Project Phase 2". Colorado Department of Transportation. Retrieved 30 May 2015.
23. "US 36 express lane tolls to begin March 30". KMGH. 2016-03-18. Retrieved 2020-01-24.
24. Proctor, Cathy (June 30, 2015). "Meet RTD's Flatiron Flyer, your new Denver-Boulder ride". Denver Business Journal. Retrieved August 21, 2015.
25. Whaley, Monte (August 18, 2015). "CU wins RTD branding agreement for DIA train". The Denver Post. Retrieved August 21, 2015.
26. Beuten, Cathy (2015-08-19). "CU partners with RTD to name airport FasTracks rail line". University of Colorado. Retrieved 2020-01-24.
27. "RTD - Northwest Rail Line". Regional Transportation District. Archived from the original on February 12, 2015. Retrieved February 11, 2015.
28. Villanueva, Raquel; McGill, Nick (25 July 2016). "RTD unveils B-Line in Westminster". TEGNA, NBC. 9News KUSA-TV. Retrieved 25 July 2016.
29. Whaley, Monte (August 29, 2012). "RTD defends FasTracks spending". The Denver Post. Retrieved 31 May 2015.
30. Whaley, Monte (January 31, 2015). "Denver is being transformed by FasTracks, 10 years after key vote". The Denver Post. Retrieved 31 May 2015.
31. "U.S. 36 reconstruction ongoing as is branding plan". Denverpost.com. 2014-11-06. Retrieved 2015-04-17.
32. "FasTracks". Broomfield Economic Development. City and County of Broomfield. Retrieved 14 November 2017.
33. Whaley, Monte (February 4, 2013). "RTD foots bill for study of northwest transit system, cities sign on". The Denver Post. Retrieved 22 April 2013.
34. "Boulder council: RTD proposals have broad impacts - Boulder Daily Camera". Dailycamera.com. 2015-02-24. Retrieved 2015-04-17.
35. "Boulder concerned about RTD transit plan along U.S. 36 - Boulder Daily Camera". Dailycamera.com. Retrieved 2015-04-17.
36. "RTD proposes cut of direct Boulder service". Denverpost.com. 22 February 2015. Retrieved 2015-04-17.
37. "East Colfax Avenue Bus Rapid Transit". www.denvergov.org. Retrieved 2025-09-25.
38. "Denver Metro Bus Rapid Transit (BRT) Project". Colorado Department of Transportation. Retrieved 2025-09-25.
39. "CO 119 Bus Rapid Transit Project". www.rtd-denver.com. 2025-05-05. Retrieved 2025-09-25.
40. "Transit". Colorado Department of Transportation. Retrieved 2025-09-25.

External links

• Official website