Significant construction work ahead on the Interstate 25 South Gap Project

News Release

June 24, 2020 - Denver Metro Area & Southeastern Colorado - Overnight closure of southbound I-25 next week


DOUGLAS/EL PASO COUNTIES—Construction is ramping up this summer on the I-25 South Gap project as crews take advantage of the warmer and drier weather to accomplish temperature-dependent operations such as asphalt paving.

This summer, crews will focus on paving, bridge construction, ramp improvements, wildlife crossings and building a truck climbing lane on southbound Monument Hill. Motorists can expect a variety of impacts along the 18-mile corridor in the coming weeks, including overnight closures of I-25 and extended lane or ramp closures.

Greenland Road traffic shift and ramp closures

What: A 12-hour single lane closure of southbound I-25 at Greenland Road directly followed by a 45-day closure of the southbound I-25 on-and off-ramps at Greenland Road.

When: 6 p.m. Thursday, June 25, to 6 a.m. Friday, June 26. Ramp closures in place 24 hours a day for 45 days.

Why: The initial lane and ramp closures will result in a major traffic shift the morning of June 26, which allows crews to construct the west half of the Greenland Road interchange. This will ultimately deliver a two-lane underpass at Greenland Road. The long-term ramp closures will allow crews to reconstruct the ramps into a new, permanent configuration.

Detours: Use County Line or Upper Lake Gulch roads 

Full closures of southbound I-25 near Larkspur

What: A series of full closures of southbound I-25 near Larkspur, between Spruce Mountain Road and Upper Lake Gulch Road.

When: 7 p.m. to 5 a.m., Sunday, June 28, Tuesday, June 30, and Wednesday, July 1. Motorists can expect impacts as early as 6 p.m. each night, as crews begin setting up traffic control signs. The interstate will be fully open during the day.

Why: Safe reconstruction of the Spruce Mountain Road bridge, which spans I-25.

Detour: Southbound I-25 traffic will funnel into one lane just north of Spruce Mountain Road, where all traffic will exit. Motorists will then take Spruce Mountain Road south to the Upper Lake Gulch Road on-ramp to continue on southbound I-25. This detour is expected to take an average of five minutes.

Northbound I-25 traffic will funnel into one lane in this area. Expect slower speeds.

Safety reminder: Traffic shifts along the corridor

Traffic shifts occur almost nightly along the 18-mile construction zone. Some of these shifts, specifically in the northern section of the project near Castle Rock, will result in less concrete barriers and wider lanes. Please remember the speed limit is 60 mph and fines are doubled in work zones. Increased enforcement is occurring on the ground and by aircraft. Exercise caution and pay extra attention as you travel the I-25 South Gap corridor.

All construction schedules are weather-dependent and subject to change. In all construction zones, please drive the posted speed limit, avoid distractions and increase your following distance.

Project Contact Information

Project Hotline: 720-745-5435


Sign up for email updates: [email protected]

Text alerts: Text I25GAP to 21000

Project Facebook Page:

For current travel information and updates, check

About the Project

CDOT is improving 18 miles of I-25 between Monument and Castle Rock by widening the highway from two to three lanes in each direction. The new lanes will operate as an Express Lanes, allowing motorists the choice of taking the Express Lanes for a faster, more reliable travel time in exchange for a toll. Express Lanes will be free to vehicles with three or more people and motorcycles. All travelers will have the choice of taking the general-purpose lanes for free.

The project also includes shoulder widening, rebuilding bridges, new wildlife crossings, resurfacing with new pavement and modernizing technology. Project completion is scheduled for 2022.

I-25 at Greenland DetourI-25 at Greenland SB DetourI-25 SB Closure Map


The following tips are to help you stay safe while traveling through maintenance and construction work zones.

  • Do not speed in work zones. Obey the posted speed limits.

  • Stay Alert! Expect the unexpected.

  • Watch for workers. Drive with caution.

  • Anticipate lane shifts and merge when directed to do so

  • Expect delays, especially during peak travel times.

  • Allow ample space between you and the car in front of you.

  • Avoid using mobile devices such as phones while driving in work zones.

  • Turn on headlights so that workers and other drivers can see you.

  • Be especially alert at night while driving in work zones.

  • Be patient!


Safe transportation infrastructure is essential for emergency first responders and freight drivers as Colorado navigates the COVID-19 pandemic. With that in mind, construction continues on CDOT projects with social distancing and other health safety measures to reduce COVID-19 exposure on the worksite. The Colorado Department of Public Health and Environment announced guidelines for construction activities. The public is urged to join the campaign for #DoingMyPartCO and practice social distancing, wear face masks, stay at home when possible, and avoid nonessential travel. With fewer vehicles on the roads, CDOT crews will be able to work more efficiently and safely.


In early 2019, CDOT announced its Whole System — Whole Safety initiative to heighten safety awareness. This initiative takes a systematic statewide approach to safety combining the benefits of CDOT’s programs that address driving behaviors, our built environment and the organization's operations. The goal is to improve the safety of Colorado’s transportation network by reducing the rate and severity of crashes and improving the safety of all transportation modes. The program has one simple mission—to get everyone home safely.


CDOT has approximately 3,000 employees located throughout Colorado, and manages more than 23,000 lane miles of highway and 3,429 bridges. CDOT also manages grant partnerships with a range of other agencies, including metropolitan planning organizations, local governments and airports. It also administers Bustang, the state-owned and operated inter-regional express service. Gov. Jared Polis has charged CDOT to further build on the state’s multimodal mobility options.