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

Crews will continue roadway tie-in work on the new portion of the US Highway 34 bridge next week and continue paving the new I-25 on- and off-ramps at US 34. To shift traffic and open work areas on US 34, full closures of the eastbound US 34 on-ramp to southbound I-25 and southbound I-25 single lane closures at US 34 will take place from 9 p.m., Monday, until 5 a.m., Tuesday, and again from 9 p.m., Tuesday, until 5 a.m., Wednesday. Eastbound US 34 traffic will go north on I-25 to Exit 259/Crossroads Boulevard, turn left and continue west on Crossroads Boulevard and turn left back onto southbound I-25.

To perform project maintenance, mobile closures will take place on I-25 project-wide from 9 p.m., Monday, until 5 a.m., Tuesday, and again from 9 p.m., Tuesday, until 5 a.m., Wednesday.

To place temporary detour pavement on northbound I-25, single lane closures will take place near Harmony Road from 9 p.m., Tuesday, until 5 a.m., Wednesday and again from 9 p.m., Wednesday, until 5 a.m., Thursday.

Roadway widening and ramp tie-in work at Prospect Road continues.

Abutment work and pier installation for bridge reconstruction will take place on the Cache La Poudre bridge between Harmony Road and Prospect Road outside the active roadway.

Concrete finishing activities on the new southbound I-25 lanes near the new Union Pacific Railroad bridge will take place to prepare to switch traffic onto the new concrete in early 2021.

Wall construction and concrete paving continue on the new northbound I-25 lanes between Colorado Highway 402 and US 34 next week.

Flagging operations will continue this week, 7 a.m. to 5 p.m., on the northbound I-25 on-ramp from Colorado Highway 60 to allow for equipment crossings. Structural support columns will be constructed for the CO 60 bridge this week at I-25 and CO 60. There will also be traffic pacing on I-25 during those hours to allow for equipment to enter and exit the work zone.
There will be a nighttime closure at the northbound I-25 on- and off-ramp from CO 60 on Thursday, 9 p.m. to 5 a.m., to accommodate the construction equipment entering and exiting the work zone.

Work this Week

Jan. 24 - 30

Lane closures for the week of Jan. 24:

  • Monday – Tuesday: Nighttime full closures of eastbound US 34 on-ramp to southbound I-25.
  • Monday – Tuesday: Nighttime southbound I-25 single lane closures at US 34.
  • Monday – Tuesday: Nighttime mobile closures from Johnstown to Fort Collins.
  • Monday - Friday: Daytime closures of northbound I-25 on-ramp from CO 60 with flaggers.
  • Monday - Friday: Daytime frontage road closure at I-25 and Weld County Road 46.
  • Tuesday - Wednesday: Nighttime northbound I-25 single lane closures at Harmony Road.
  • Thursday: Nighttime northbound I-25 on- and off-ramp closure at CO 60.

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.

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