I-25 North Express Lanes: 120th to Northwest Parkway/E-470

Project Facts

  • Goal: Increase mobility and travel choice along a six-mile segment of I-25 by building an Express Lane in each direction of a highway that connects downtown Denver to major growth in northern Colorado.
  • Cost: $21.5 million
  • Timeline: March 2019 - summer 2020
  • Contractor: Graham Contracting Ltd.
  • Location: I-25 between 112th Avenue and Northwest Parkway/E-470
north i 25 express lanes


In August 2011, CDOT completed a Final Environmental Impact Statement (FEIS), which identified and evaluated multi-modal transportation improvements for I-25, including the stretch between US 36 and Colorado Highway 7—among the most congested in the Denver metro area. (On average, 174,000 vehicles travel this stretch each day.) The FEIS' preferred alternative for the corridor will increase safety, capacity and user choice.


  1. Spring 2016 - Fall 2018
    Crews focused on the outside portions of I-25 and completed ramp reconfiguration work.

  2. Started in March 2019 and ongoing
    Crews are focusing on the inside portion of I-25 by:
    • installing new concrete median barrier and lighting;
    • incorporating tolling infrastructure for the new Express Lanes;
    • making technology improvements;
    • resurfacing the pavement with new asphalt;
    • restriping the roadway; and
    • completing ramp improvements, including metering, to improve operations.

Schedule & Travel Impacts

Week of January 20

Overnight (10 p.m. to 4 a.m.) on Monday, Jan. 20 –Northbound I-25 closure between 120th Avenue and 136th Avenue, along with a full closure of the 120th Avenue on-ramp to northbound I-25 and the northbound I-25 off-ramp to 136th Avenue. Motorists should exit northbound I-25 at 120th Avenue, travel east to Washington Street, north on Washington Street then west on 136th Avenue to reenter northbound I-25. No closures on southbound I-25.

This work is weather dependent and subject to change.

Detour Routes:

n i-25 detour route.png

Commercial Vehicle (HAZMAT and Oversize/Overweight) Detour Routes:

  • Southbound I-25 Detour - Commercial vehicles will exit southbound I-25 at CO 7, travel west to southbound US 287, then travel east on 120th Avenue/US 287 to reenter southbound I-25.
  • Northbound I-25 Detour - Commercial vehicles will exit northbound I-25 at 104th Avenue/CO 44, travel east to northbound US 85, then travel west on CO 7 to reenter northbound I-25.

Commercial Truck Detour Map


This project will:

  • Add capacity and ultimately provide the choice of a reliable trip with the addition of one HOV/Express Lane in both directions of I-25.
  • Install an auxiliary lane along northbound I-25 to connect the 136th Avenue on-ramp to the 144th Avenue off-ramp, which will help drivers merge more comfortably between the two interchanges.
  • Improve driving conditions by resurfacing the roadway.
  • Address necessary drainage and utility improvements along the corridor.
  • Improve technology.
  • Improve operations at ramps through traffic metering devices.

How to use Express Lanes

Express Lanes increase roadway capacity and help manage congestion on Colorado highways by adding lanes that provide a new choice to drivers. Motorists can choose to ride the bus, carpool or pay a toll to use the new Express Lanes as an alternative to the free, general purpose lanes.

Colorado: The Official State Web Portal