B Line

Facts

  • Length (miles): 5.7 miles (41 miles future total)
  • Vehicle Type:
    • Denver to Westminster: Electric
    • Westminster to Longmont: Diesel
  • Stations: Currently 4: Union Station, 41st• & Fox, Pecos Junction, and Westminster; when fully built out 6 additional stations: Downtown Westminster, Broomfield, Flatiron, Downtown Louisville, Boulder Junction at Depot Square, and Downtown Longmont
  • Parking: 1,150 spaces
  • Service Frequency: 60 min

At a Glance

  • The B Line, also referred to as the Northwest Rail Line, is part of RTD’s 2004 voter-approved FasTracks plan to expand transit across the Denver metro region.
  • The proposed 41-mile diesel commuter rail corridor would operate between Denver’s Union Station and Longmont, passing through north Denver, Adams County, Westminster, Broomfield, Louisville, Boulder, and Boulder County.
  • As part of the FasTracks plan in 2004 and subsequent studies and agency coordination, there are four existing stations: Denver Union Station, 41st•Fox (B and G lines), Pecos Junction (B and G lines), and Westminster–72nd (B Line). The Northwest Rail Peak Service Feasibility Study, authorized in 2022 by the RTD Board of Directors, proposed the following six additional stations: Downtown Westminster, Broomfield–116th, Flatiron (Broomfield), Downtown Louisville, Boulder Junction at Depot Square, and Downtown Longmont.

Project Overview

  • 2010: RTD FasTracks Environmental Evaluation was completed, identifying the benefits and effects of implementing transit on BNSF Railway right-of-way.
  • 2012: Construction of the first 6.2-mile electrified segment between Union and Westminster stations began as part of the Eagle P3 project set to open in 2016.
  • 2013-2014: RTD and its contractor completed the Northwest Area Mobility Study to determine the best mobility options for northwest communities including, the feasibility of building the Northwest Rail in phases and providing arterial bus rapid transit.
  • 2015-2016: RTD FasTracks earmarked $17 million to build the first phase of the end-of-line station in Longmont under a construction-ready plan; RTD will use the station for bus transfers then upgrade to a rail/bus facility after it completes the B Line Rail. Construction of the station will begin in 2015 and end in 2016.
  • 2016: The first B Line segment opened on July 25. RTD will begin additional construction when funding becomes available.
  • 2021: RTD Board approves study of a “peak service” rail schedule to northwest communities and supports the majority of 43 recommendations forwarded by an independent accountability committee
  • 2022: RTD initiates the Northwest Rail Peak Service Feasibility Study to examine use of the agency’s existing B Line commuter rail alignment, along with the possibility of leasing BNSF Railway right-of-way and tracks, to extend service during peak commuting hours from Westminster Station 35.3 miles north to Boulder and Longmont

Ridership

Boardings regularly fluctuate due to many factors, including economic conditions, seasonal demands, remote work trends, service disruptions, large events, and activities. A regularly updated overview of RTD's ridership is available online in the Board Briefing Documents.

  • 2024 Total Ridership: 145,000
  • 2023 Total Ridership: 157,000
  • 2022 Total Ridership: 152,000