Project History

Project History

The EIS analyzed potential transportation improvements along the I-25 corridor between Fort Collins/Wellington and downtown Denver, as well as US along 85 and US 287. The Preferred Alternative as identified in the final EIS includes the following transportation improvements, with an estimated total cost of $2.18 billion (2009 dollars):

  • General Purposes Lanes- One new general purpose lane in each direction of I-25 between State Highway (SH) 66 and SH 14.
  • Tolled Express Lanes (TEL)- One buffer-separated TEL in each direction of I-25 from the existing HOV/Express Toll Lanes at approximately 84th Avenue in Denver to SH 14.
  • Interchange Upgrades- Upgrades 13 interchanges along I-25.
  • Express Bus- Express bus with 13 stations along I-25, US 34 and Harmony Road with service from Fort Collins and Greeley to downtown Denver and DIA.
  • Commuter Rail- Commuter rail service with nine stations connecting Fort Collins to Longmont using the Burlington Northern Santa Fe Railroad right-of-way, generally paralleling SH 119 then County Road 7 and tying into FasTracks North Metro line in Thornton, providing service to downtown Denver. Passengers may also connect to the FasTracks Northwest line in Longmont, which will travel to Boulder.
  • Commuter Bus- Commuter bus service with eight stations and stops along US 85 connecting Greeley to downtown Denver.
  • Congestion Management- Includes accommodations for ridesharing, carpools and vanpools along with additional bicycle and pedestrian facilities. In addition, signal timing, ramp metering on I-25, and signage will also be improved.

Due to funding limitations, the Preferred Alternative will be constructed in phases over time. Construction of the first phase is estimated to cost $670 million (2009 dollars) and is scheduled to be complete by 2035 based on current funding. Phase 1 was approved in the (ROD) by the Federal Highway Administration (FHWA) and includes:

  • General Purpose Acceleration/Deceleration Lanes - Reconstructing and widening I-25 between SH 14 and SH 392 to add continuous acceleration/deceleration lanes that would ultimately become part of the eight-lane configuration in the future
  • Tolled Express Lanes – Adding one buffer-separated TEL in each direction on I-25 between SH 56 and SH 66, and between 120th Avenue and US 36 (connecting to the existing I-25 Express Lane facility to downtown Denver)
  • Interchange Upgrades – Upgrading six interchanges along I-25 including SH 14, Prospect Road, US 34 (Phase 1 includes construction of an interchange at US 34/Centerra Parkway), SH 56, WCR 34 and SH 7.
  • Express Bus – Initial express bus service with six stations/stops along I-25, US 34 and Harmony Road with service from Fort Collins and Greeley to downtown Denver and DIA.
  • Commuter Bus - Commuter bus service along US 85 connecting Greeley to downtown Denver.
  • Carpool lots - Constructing six carpool lots along I-25, several of which will be shared with the I-25 express bus transit stations.

In addition, right-of-way for future commuter rail implementation will be purchased in phase one using state funds.