Extensive Lane Closure on I-25 This Weekend

August 13, 2019 - Denver Metro Area, Colorado

MONUMENT - The Colorado Department of Transportation will reduce southbound Interstate 25 to one lane for 16 hours this weekend to complete drainage improvements at the southern end of the project.  

Beginning at 7 p.m. on Saturday, Aug. 17, and continuing until 11 a.m. on Sunday, Aug. 18, one lane of southbound I-25 will be closed for two miles – from County Line Road to Highway 105 in Monument.  One lane will remain open.  However, extensive delays are anticipated and motorists are encouraged to plan ahead and add extra time if traveling south of Larkspur. 

All construction is weather-dependent and subject to change.

Project Contact Information

Project Hotline: 720-745-5435

Web: i25gap.codot.gov

Sign up for email updates: [email protected]

Text alerts: Text I25GAP to 21000

Project Facebook Page: Facebook.com/I25SouthGapProject

The following safety measures have been implemented on the project:

  • Reduced speed limit to 60 mph and installed Portable Variable Speed Limit Signs, which allow the project to adjust speed limits in real-time based on weather conditions, crashes, or construction-related impacts. With this technology, crews can slow down traffic ahead of a crash, incident or weather impact, possibly reducing the likelihood of secondary crashes.
  • Daily enforcement in the work zone by the Colorado State Patrol.
  • Ensure adequate first responder access by providing access breaks in the barrier where possible. 
  • Intermittent shoulder pull-off locations for emergencies. 
  • Limit lane closures to off-peak travel periods at night unless emergency situations warrant a lane closure such as road damage repairs or other emergency situations.
  • No detouring traffic to alternate routes.
  • Multiple courtesy patrol vehicles dedicated to the project work zone, which helps get disabled vehicles off the road and traffic moving.
  • Monitor traffic through a project operations center that uses cameras, signs and vehicle detection devices to help with incident management.
  • Deployed Smart Work Zone systems and devices that warn motorists of backed up traffic, trucks entering and exiting the work zone and other incidents and activities. 
  • Stage equipment prior to large snow events to assist with snow operations and response issues.
  • Hold bi-weekly meetings with emergency response agency partners to coordinate efforts on project operations and work zone safety.
  • Implemented significant safety improvements on the frontage roads between Larkspur and Castle Rock.
  • Employed extensive public relations efforts including text alerts, social media, special media briefing events, paid advertising campaigns, public meetings, weekly e-blasts to stakeholders, regular meetings with stakeholders and elected officials, coordinating seamlessly between two counties.
  • Added Bustang routes and ride-sharing program to give motorists other travel options during construction.
  • Provided an extra lane for the Renaissance Festival, which helped alleviate traffic congestion on southbound I-25 during this 8-week event, which concluded in early August.

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 lane will operate as an Express Lane, allowing motorists the choice of taking the Express Lane 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 $350 million project also includes shoulder widening, rebuilding bridges, new wildlife crossings, resurfacing with new pavement and modernizing technology. Project completion will occur in 2022.

Travel options to improve commutes are available during construction. Some of the services include a new Bustang route from Colorado Springs to the Denver Tech Center. CDOT is partnering with the Denver Regional Council of Governments' Way to Go program to provide more commuting options, such as incentives to vanpool and carpool. Visit i25myway.org to learn more.


Whole System - Whole Safety  

To heighten safety awareness, CDOT recently announced its Whole System. Whole Safety initiative. This project 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 safety conditions for those traveling by 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 interregional express service. Gov. Jared Polis has charged CDOT to further build on the state’s intermodal mobility options.