N Line
Skyway Bridge over Brighton Boulevard during construction.
OwnerRegional Transportation District
LocaleDenver metropolitan area
TerminiUnion Station
9 (proposed)
WebsiteMetro North Rail Line
TypeCommuter Rail
SystemRegional Transportation District
Operator(s)Regional Transportation District
OpenedSeptember 21, 2020; 14 months ago (2020-09-21)
Line length13 miles (21 km) (initial segment)
18.5 miles (29.8 km) (proposed)
Track gauge4 ft 8+12 in (1,435 mm)
ElectrificationOverhead lines, 25k V AC 60 Hz
Operating speed79 mph (127 km/h) (top)
Route diagram

proposed extension
proposed extension
North Thornton/Hwy 7
fare zone boundary
Thornton Crossroads/104th
Original Thornton/88th
fare zone boundary
SH 224
74th Avenue
Commerce City/72nd
Skyway Bridge
48th & Brighton/
National Western Center
 B  G 
Union Station
Amtrak A  B  G 
 C  E  W 

The N Line, also known as the North Metro Rail Line during construction,[1] is a commuter rail line which is part of the commuter and light rail system owned by the Regional Transportation District (RTD) in the Denver metropolitan area in Colorado. The first 13 miles (21 km) from downtown Denver to 124th Avenue in Thornton opened as part of the FasTracks expansion plan on September 21, 2020.[2] When fully built out the line will be 18.5 miles (29.8 km) long and pass through Denver, Commerce City, Northglenn, and Thornton.[3] The N Line features Colorado's longest bridge at 9,533 feet (1.8 mi; 2.9 km) called the Skyway Bridge.[4] While other RTD commuter lines are operated by Denver Transit Partners for RTD, this is the only line operated by RTD itself.[5]


The possibilities and studies for a rail line in the North Metropolitan Denver have existed since the opening of the Light Rail Central Corridor in 1994. In the 2004 election year voters approved the North Metro Corridor as part of the RTD FasTracks expansion plan. In September 2006 the Environmental Impact Statement (EIS) was started, with completion in late 2010, and gaining approval by the Federal Transit Administration in April 2011.[6] A preexisting railroad right-of-way for the line was purchased in 2009. The contract to build the North Metro Rail line to 124th Avenue was awarded to Graham, Balfour Beatty, Hamon Constructors (GBBH) in November 2013 with notice to proceed in December 2013.[7] The GBBH contract included an option that when funding is available RTD can exercise the option to build the line to 162nd Avenue.

Groundbreaking of the N Line's construction occurred on March 20, 2014[8] with an expected completion date in 2018. The GBBH joint Venture is operating under the name Regional Rail Partners (RRP).[9] By August 2018, construction on the line was 85% complete, but the estimated completion had slipped to late 2020 or early 2021;[5] the start of revenue service had again been delayed several months by September 2019.[10] Despite slowdowns caused by the COVID-19 pandemic, the line started operation on September 21, 2020.[2][11]


The N Line's southern terminus is at Union Station in Denver. It runs mostly on a preexisting railroad right-of-way to its northern terminus at Eastlake/124th station.[12][13][14] A notable exception to using the existing railroad right-of-way is the RTD designated "Skyway Bridge" whose path takes it over and past several obstacles: it crosses the BNSF Railway railroad tracks, Brighton Boulevard, a Union Pacific Railroad spur track, the Farmers Reservoir and Irrigation Company (FRICO) Ditch, the Metro Waste Water Plant and Suncor oil processing site, Sand Creek, and Interstate 270.[4]

The N line route leaves Union Station following the Union Pacific / BNSF corridor, near Coors Field it crosses over the rail yards and twice the South Platte River continuing northeast into the 48th & Brighton/National Western Center station located near the National Western Stock Show complex. The northeasterly line near Riverside Cemetery then enters the Skyway Bridge to begin a northern path returning to grade level near the Commerce City/72nd station following again the former rail right of way into the station. From there it passes under Interstate 76 and Colorado State Highway 224, then again over the South Platte River following a slightly northwest path north until the Original Thornton/88th station. Then, on a slight northeast path, the line near 100th Avenue curves northwest into the Thornton Crossroads/104th station. On a northwest path the line continues until near East 112th Avenue where in travels north into the Northglenn/112th station. On a northward path the line arrives at Eastlake/124th station, the site of a historic grain elevator and Eastlake, Colorado.


Name Opening Year Interchange Municipality Park and Ride[15] Status
Union Station 2014  A   B   C   E   G   W 
Amtrak California Zephyr
Denver No Open
48th & Brighton/National Western Center 2020 Denver No Open
Commerce City/72nd 2020 Commerce City Yes Open
Original Thornton/88th 2020 Thornton Yes Open
Thornton Crossroads/104th 2020 Thornton Yes Open
Northglenn/112th 2020 Northglenn Yes Open
Eastlake/124th 2020 Thornton Yes Open
York/144th 2042[16] Thornton Yes Proposed
North Thornton/Hwy 7 2042[16] Thornton Yes Proposed


Main article: FasTracks

In 2004 Colorado voters approved FasTracks, a multibillion-dollar public transportation expansion plan. In 2009 RTD paid $117 million ($141 million adjusted for inflation) to purchase the right-of-way from Union Pacific in preparation for the build-out of the North Metro rail line. Budgeting issues set back FasTracks plans, including those for the N Line. Construction of the line was able to proceed when RTD partnered with a private firm to build the line in 2 stages. The first stage will build the line to the 124th Avenue Station with an opening in 2020, while the second stage to North Thornton/Hwy 7 station will commence when projected ridership makes economic sense.[17]


  1. ^ "N Line". RTD - Denver.
  2. ^ a b Padilla, Anica (21 September 2020). "All Aboard: RTD's N Line Starts Rolling From Denver To Thornton". CBS Denver. Retrieved 21 September 2020.
  3. ^ "RTD - North Metro Rail Line". Regional Transportation District. Retrieved February 17, 2015.
  4. ^ a b "RTD - North Metro Rail Line Newsletter" (PDF). Regional Transportation District. Retrieved January 22, 2015.
  5. ^ a b Minor, Nathaniel (13 August 2018). "2020 Is RTD's New 'Ballpark' Estimate For North Metro Rail Line". Colorado Public Radio. Retrieved 14 August 2018.
  6. ^ "RTD - North Metro Rail Line - Project History". Regional Transportation District. Retrieved May 17, 2015.
  7. ^ "RTD - GBBH wins contract to build North Metro Rail Line". Regional Transportation District. Retrieved May 17, 2015.
  8. ^ "RTD - Press release North Metro Rail Line is one step closer to reality" (PDF). Regional Transportation District. Retrieved May 17, 2015.
  9. ^ "Regional Rail Partners – Building Commuter Rail in North Denver". Regional Rail Partners (RRP). Retrieved 13 July 2017.
  10. ^ Kesting, Amanda (24 September 2019). "Opening of commuter line to Thornton delayed again". NBC. 9News. Retrieved 25 September 2019.
  11. ^ Minor, Nathaniel (20 May 2020). "One Thing Not Derailed By Coronavirus? RTD's N Line Now 'On Track' To Open By September". Colorado Public Radio. Retrieved 25 May 2020.
  12. ^ "RTD - North Metro Rail Line Home". Regional Transportation District. Retrieved February 17, 2015.
  13. ^ "RTD - North Metro Rail Line Stations". Regional Transportation District. Retrieved April 29, 2015.
  14. ^ "RTD - FasTracks System Map". Regional Transportation District. Archived from the original on December 23, 2013. Retrieved May 12, 2015.
  15. ^ "N Line Map". RTD. Retrieved 18 September 2020.
  16. ^ a b "RTD". www3.rtd-denver.com. Retrieved 2019-07-15. If RTD does not secure additional revenues, current estimates indicate that the entire FasTracks system will not be completed until 2042.
  17. ^ Monte Whaley (November 26, 2013). "Denver's northern suburbs welcome RTD rail line". The Denver Post. Retrieved December 12, 2013.

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