Traffic Impacts

All work is weather dependent and will be rescheduled if operations cannot be completed.

Motorists have likely noticed a series of permanent frontage road closures along I-25 North. Eventually, the frontage road will close permanently between Colorado Highway 66 to US 34 with a section between Larimer County Road 14 to Colorado Highway 402 remaining open. These closures will not only allow for the expansion of I-25 North, but also a newer, safer north-south arterial called the High Plains Boulevard.

When I-25 was built in the 1960s, 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 interstate. Today, the frontage road handles more traffic and functions as a major north-south arterial, creating large safety concerns, problematic and confusing spacing between intersections, and development access issues. Some safety issues as supported by accident history and emergency management 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.
  • The I-25 speed limit in much of northern Colorado is 75 mph with a minimum clear zone of 30 feet 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 minimum distance between interstate on- and off-ramps and the frontage road intersection, specifically at the Colorado Highway 56 and Colorado Highway 60 interchanges. 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 and efficiency 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 to a implement a long-term plan that will encourage safe and efficient traffic flow. A unique opportunity exists to leverage impending development and partnerships to help build a new north/south road approximately ½ mile to the east of I-25, deemed High Plains Boulevard, that will better serve the overall system than the frontage road is able.

An advisory committee has been formed for the High Plains Boulevard that includes members from Berthoud, Johnstown, Larimer County, Loveland, Mead and Weld County. The committee worked together to determine road alignment, design criteria and corridor characteristics including design speeds, typical roadway templates, drainage standards and right-of-way needs. High Plains Boulevard will eventually extend from Colorado Highway 66 to US 34 in northern Colorado when it is fully constructed. This new highway will give commuters an alternative north-south option through northern Colorado besides I-25.

Construction of High Plains Boulevard will begin in 2021, on the stretch from Weld County Road 38 to Colorado Highway 56/Weld County Road 44. Over time, the full boulevard will be built out, and it will extend from CO 66 to US 34. Until then, there will be several local detours throughout the area as each section of the frontage road begins to close, as shown on this map. When the I-25 North Express Lanes project is complete, only property owners and utility companies will have access to certain portions of the frontage road. The section of frontage road between Larimer County Road 14 to Colorado Highway 402 will become a local Johnstown road and will remain open to service various businesses that exist in this section.

Travelers can use local roads (Colorado Blvd, County Line Road, etc.) during the time between frontage road closures and construction of High Plains Construction for the High Plains Boulevard project will vary section by section and will most likely be driven by development in the area. The first section between WCR 38 and CO 56 is projected to be completed by late 2021.

Constuction Activities & Impacts

To remove temporary bridge falsework at Prospect Road, full closures of I-25 at Prospect Road and Prospect Road over I-25 will take place from 9 p.m., Thursday, until 5 a.m., Friday.

  • Westbound Prospect Road traffic will be detoured north on I-25 to Exit 269/Mulberry Street and back onto southbound I-25 to Exit 268/Prospect Road.
  • Eastbound Prospect Road traffic will be detoured south on I-25 to Exit 265/Harmony Road and back onto northbound I-25 to Exit 268/Prospect Road.
  • I-25 traffic will be detoured up and over I-25 using the on- and off-ramps at Exit 268/Prospect Road.

To shift traffic and open work areas for ramp reconstruction, a full closure of the southbound I-25 on-ramp from eastbound US Highway 34 and a single lane closure on eastbound US 34 will take place from 9 p.m., Monday, until 5 a.m., Tuesday.

  • Southbound I-25 traffic will go north on I-25 to Exit 259/ Crossroads Boulevard and turn left. Continue west to the southbound I-25 on-ramp.

To perform underground work, set temporary barrier and shift traffic, single lane closures will take place on I-25 near Harmony Road, 9 p.m. to 5 a.m., Sunday through Wednesday.

Northbound I-25 traffic and traffic on the northbound I-25 on-ramp from Harmony Road will be shifted to the west next week into a new temporary roadway alignment. Northbound on-ramp traffic from Harmony Road can expect a new ramp configuration as they enter I-25. Please use caution. To perform this work, a full closure of the northbound I-25 on-ramp from Harmony Road will take place from 9 p.m., Tuesday, until 5 a.m., Wednesday.

  • Northbound I-25 traffic will go south on I-25 to Exit 262/ Colorado Highway 392 and turn left. Continue east to the northbound I-25 on-ramp.

A single lane closure on I-25 will take place project-wide, 9 p.m. to 5 a.m., Monday through Wednesday, to perform necessary project maintenance.

On Monday, Feb. 22, 9 p.m. to 5 a.m., the southbound I-25 on-ramp from Colorado Highway 60 will be closed for equipment mobilization. Motorists should use Colorado Highway 56 or Colorado Highway 402 to access southbound I-25. The flagging operations scheduled for CO 60 overnight Monday have been canceled due to work being completed ahead of schedule.

Flagging operations will continue this week at the Frontage Road and Larimer County Road 16 intersection to allow for equipment to safely enter and exit the work zone.
Structural support is being placed behind the south bridge abutments, located at I-25 and Colorado Highway 60. Installation work for a 48-inch drainage line west of CO 60 and I-25 will also begin.
There will be a nighttime closure of the northbound I-25 on- and off-ramps at CO 60, Tuesday -  Thursday, 9 p.m. to 5 a.m., to accommodate construction equipment entering and exiting the work zone.
Traffic pacing operations on southbound I-25 at CO 60 will take place Monday through Friday to accommodate the construction equipment entering and exiting the work zone.
In order to set barrier, there will be a single lane closure on northbound I-25 starting at CO 56 and moving north, Sunday night through Thursday night.

Work this Week

Feb. 28-March 6

Lane closures from Sunday, Feb. 28 through Saturday, March 6: 

  • Sunday: Nighttimeclosures on I-25 between LCR 16 and CO 402 -- northbound I-25 right lane closure and off-ramps, and southbound left lane of I-25.
  • Sunday: Nighttime northbound I-25 right lane closure and southbound I-25 left lane closure, between LCR 16 and CO 402.
  • Monday: Nighttimesouthbound I-25 left lane closure, south of CO 402, and nighttime southbound I-25 right lane closure, south of LCR 14.
  • Monday: Nighttime southbound I-25 right lane closure, south of Weld County Road 46.
  • Monday - Thursday: Early morning closures of southbound I-25 on- and off-ramps at CO 60.
  • Monday - Thursday: Daytime traffic pacing operations on southbound I-25, between CO 60 and CO 402.
  • Monday: Daytime full closure on LCR 14 at I-25.
  • Monday: Daytime flagging operations with intermittent traffic stops on LCR 14 and the Frontage Road.
  • Monday - Thursday: Daytime all-way flagging operations and intermittent traffic stops at the LCR 16 and Frontage Road intersection.
  • Tuesday - Thursday: Nighttime southbound I-25 right lane closure, south of WCR 46.
  • Tuesday - Thursday: Nighttime northbound I-25 left lane closure at Little Thompson Bridge.
  • Monday– Wednesday: Nighttime I-25 single lane closures at Harmony Road.
  • Sunday– Friday: Nighttime I-25 single lane closures project-wide

Extended Closures

 I-25 frontage road (WCR 44 to Valley Road intersection) near the Berthoud exit - PERMANENTLY CLOSED

On July 27, the eastern I-25 frontage road between Weld County Road 44 and the intersection of Valley Road closed permanently to allow crews to safely realign I-25 at the CO 56 intersection and improve the intersection altogether. In the long term, this closure will allow for the expansion and additional lanes on I-25 North.

Through access will no longer be available. Additionally, the Berthoud Park and Ride will close for approximately one week beginning July 27. The lot will be temporarily relocated to a site accessed from Weld County Road 44 before it is relocated to its final site. Please follow posted signage in the area and plan accordingly.

Construction is weather-dependent and subject to change.

Park and Ride Locations

East Frontage Road (Prospect Rd to Mulberry St) - PERMANENTLY CLOSED


I-25 North Frontage Road near Berthoud now permanently CLOSED

The I-25 frontage road between Colorado Highway 56/Weld County Road 44 to WCR 46 is now permanently closed. 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.

The frontage road between Larimer County Road 14 and Colorado Highway 402 remains in place due to the number of business accesses.

Updated Jan. 6 Alternative Routes Map

Click the button below to view CDOT’s I-25 Frontage Road Vision.

Colorado: The Official State Web Portal