I-25 North Express Lanes

The expansion of I-25, by Colorado Department of Transportation (CDOT), with an Express Lane in each direction, will provide trip reliability, safety improvements and more for Northern Colorado. 

Key Project Features

  • Increase capacity by adding an Express Lane in both directions, replacing four aging bridges and widening four additional bridges.
  • Improve multi-modal access to regional transit to promote mode shift.
  • Improve bus service performance and reduce each total trip time by 15 minutes by adding new bus slip ramps from I-25 to the new Park-n-Ride at Kendall Parkway.
  • Create new pedestrian, bicycle access under I-25 at Kendall Parkway.
  • Connect the Cache la Poudre River Regional Trail under I-25 and network to 100 miles of total trails. It will also serve as a wildlife corridor.

Update from CDOT – I-25 North Express Lanes Between Berthoud and Johnstown – 12-30-19
Beginning on Jan. 6, the I-25 frontage road between Colorado Highway 56/Weld County Road (WCR) 44 to WCR 46 will permanently close. This closure is the first phase of a larger frontage road closure plan. All properties and utility companies will have access maintained to their property. It should be noted that the frontage road between Larimer County Road 14 and Colorado Highway 402 will remain in place due to the number of business accesses.

Project flyers and VMS boards began to notify local residents and property owners of this closure this week, and a press release is scheduled to be distributed soon. The project team will continue to message detour routes and other pertinent project information as this work progresses.

CDOT’s I-25 Frontage Road Vision 
When I-25 was built in the 1960’s, the old highway was turned into the current frontage road so that property owners could maintain access to their land. It was never intended to be an alternate through route adjacent to the highway. Today, the frontage road handles more traffic and functions as a major north-south arterial, creating large safety concerns and development access issues. Some safety issues as supported by accident history include:

  • The close proximity between the frontage road and I-25 sometimes makes it difficult to decipher if oncoming cars are on the highway or the frontage road and what speed they are traveling at, especially at night. Motorists pulling onto the frontage road have a difficult time deciphering these cars and sometimes pull out in front of a vehicle on the frontage road because they thought it was on I-25, creating dangerous high-speed collisions.
  • I-25 speed limit in much of northern Colorado is 75 mph with a minimum clear zone of 30’ on either side of the interstate. The clear zone is the space outside of a highway that is designed to hold traffic accidents and emergency responders without impacting traffic flows. For much of the corridor, the frontage roads are within or close to the clear zone of I-25, creating dangerous head-to-head conditions if cars were to leave the interstate and inadvertently travel into oncoming frontage road traffic.
  • Some vehicles illegally “jump off” I-25 when congestion exists to use the frontage road. This situation is unsafe and burdens law enforcement when they are busy dealing with the cause of the congestion.
  • The current frontage road alignment does not adhere to the required minimal distance between interstate on- and off-ramps and the frontage road intersection, as is the case at the Colorado Highway 60 interchange. The close proximity of the intersections causes driver confusion, especially drivers who want to turn right on red coming from the off-ramp and are in direct conflict of north/south movements from the frontage road. The functionality of the interchange also suffers due to the multiple traffic signal phases that exist for the frontage road movements.

Community leaders, emergency management and transportation agencies have identified this problem and recognize the transportation network is at a pivotal moment to provide a guiding vision that will encourage safe and efficient traffic flow. While much of the land adjacent to I-25 is currently agriculture, a unique opportunity exists to leverage impending development and partnerships to help drive a new north/south road approximately ½ mile to the east of I-25, deemed the I-25 Parallel Arterial (IPA), that will better serve the overall system than the frontage road is able.

In order to progress the IPA, an advisory committee has been formed that includes members from Berthoud, Johnstown, Larimer County, Loveland, Mead and Weld County. The committee is working together to determine road alignment, design criteria and corridor characteristics including design speeds, typical roadway templates, drainage standards and right-of-way needs. The I-25 Parallel Arterial will eventually extend from Colorado Highway 66 to US 34 in Northern Colorado when it is fully constructed.

Additionally, I-25 is being widened from CO 56 to Colorado Highway 14 to accommodate an express lane in each direction and reconstruct interchanges. During the design process, the I-25 project team evaluated the function, impact and cost of improving the frontage roads, specifically focusing on what’s best for the overall transportation system and knowing the functional life would suffer in the future due to the increase of traffic. This evaluation presented an opportunity to work with the IPA team to globally identify a transportation solution, as well as cut down the I-25 widening right-of-way needs by approximately 143 acres between Colorado Highway 66 and Larimer County Road 14.

As part of the I-25 project from Berthoud to Johnstown (Segment 6) design and construction process, this team has been coordinating with property owners adjacent to I-25, determining how best to minimize right-of-way impacts, strategizing current and future regional transportation flows and networks, ensuring access is maintained, and evaluating how best to use project resources while minimizing future waste. Part of the strategy involves strategically closing down sections of the frontage road so the frontage road land can be used for I-25 widening.

Eventually, large sections of the frontage road will be closed from Colorado Highway 66 to Ronald Reagan Boulevard in conjunction with the I-25 widening project. All frontage road closures will be messaged ahead of time with press releases and updates on CDOT’s website (https://www.codot.gov/projects/north-i-25/johnstown-to-fort-collins/johnstown-to-fort-collins).

The frontage road was not designed or intended to handle the traffic volumes it now holds or would have in the future due to northern Colorado’s growth. Ultimately, the IPA will provide a safer, more comprehensive north-south alternative that will help keep drivers safe and alleviate some of the congestion on I-25.

For all traffic updates related to this project, visit the I-25 North Express Lanes project webpage.

I-25 and CO 402 Interchange Grand Opening
The I-25 and CO 402 interchange officially opened to traffic on Friday, Oct. 18, following the grand opening event celebrating the new bridge that crews built aboveI-25 and three roundabouts, marking the end of the 120-day project, funded withhelp of Johnstown, Loveland, Weld and Larimer Counties. 

Mayor Gary Lebsack and other state and local dignitaries addressed thecrowd and the importance of projects like these the provide better infrastructurefor our rapidly growing region.

402 Interchange Grand Opening 1 (Photo Credit: Nikki A. Rae Photography. Nikki A. Rae Photography retains the copyright to the images. Images cannot be used in advertising, contests, or for financial gain without written approval.)

--- (9/29/19) ---

Starting Sunday, Sept. 29, CDOT began construction on the I-25 North: Berthoud to Johnstown Express Lanes Project, the next phase of improvements along I-25 in northern Colorado. Construction will start with reconstructing the southbound I-25 bridge over Little Thompson River, as well as elongating the southbound on-ramp from Colorado Highway 56 to allow for a safer merge. 

The full closure of eastbound and westbound Colorado Highway 402 from the southbound I-25 on- and off-ramps to the new East Frontage Road is ongoing as crews continue daytime and nighttime bridge construction, lighting and cable rail installation, drainage work and landscaping, and signage operations at the future roundabouts and ramps. Crews will also conduct paving operations on I-25 mainline and shoulders at CO 402. 

A full closure of the southbound I-25 on-ramp from CO 392 will be required on Sunday, September 29, 9 p.m. to 5 a.m. to perform earthwork operations.  On-ramp traffic will detour on northbound on I-25 to Harmony Road, and back onto southbound I-25.

Crews will require full closures of the southbound I-25 on- and off-ramps at CO 402 for striping operations. SB off-ramp traffic will detour to Exit 252 CO 60 East, turn west onto CR 48, then north on CR 7 back to CO 402. SB on-ramp traffic will detour south on County Road 7 then east on CR 48 to the southbound I-25 on-ramp. 

Work on the new Prospect Road bridge over I-25 continues with abutment work. In order to set girders on the new Prospect Road bridge over I-25, a full closure of northbound and southbound I-25 at Prospect Road and a full closure of Prospect Road over I-25 will be in place on Tuesday, Oct. 8 and Wednesday, Oct. 9 from 9 p.m. to 5 a.m.

On Thursday, Oct. 10 and Sunday, Oct. 13, a full closure of northbound and southbound I-25 at Prospect Road will be in place from 9 p.m. to 5 a.m. to form the deck of the new Prospect Road Bridge over I-25.  All I-25 on- and off-ramps will remain open during the deck forming operation. Westbound Prospect Road traffic will be detoured north to Mulberry Street. Eastbound Prospect Road traffic will be detoured south to Harmony Road and I-25 traffic will be detoured using the on- and off-ramps at Prospect Road.

For specific lane closures and traffic impacts from Sunday, Sept. 29 - Saturday, Oct. 5, please use this interactive map on the project webpage. To display full details on the traffic impacts, please click on any of the color shaded areas on the map to see full details. A pop-up on the left side of your screen will outline the details of the lane closures.

Construction activities are weather dependent and subject to change. Please watch for construction vehicles entering and exiting mainline I-25 and obey all posted signage in construction zones. Your safety and the safety of our crews is our highest priority.

The I-25 North Express Lanes Project provides a Courtesy Patrol during commute hours (6 to 9 a.m. and 3:30 to 6:30 p.m.) to assist with disabled vehicles within the Project limits from Johnstown to Fort Collins.

To stay up-to-date on construction information and keep yourself informed on I-25 North Express Lanes: Johnstown to Fort Collins Project news, call the Project hotline at 720-593-1996 or sign up for emails at northi25expresslanes@gmail.com.

More information about this project is available at: