Major impacts expected on I-25 near Monument April 9–17 for bridge and drainage work

Travel Advisory

April 8, 2021 - Denver Metro/Southeastern Colorado - Single lane closures through the weekend and full overnight highway closures through next week, 20-minute delays expected

MONUMENT – As part of the Interstate 25 South Gap project between Monument and Castle Rock, drivers should expect delays on I-25 near Monument for County Line Road bridge construction and drainage improvements over the next several days.  

16-hour single lane closures - this weekend (April 9 to 11)

  • There will be a single lane closure of southbound I-25 near County Line Road overnight Saturday for drainage work. Motorists should watch for ramp closures at County Line Road. 

Full highway closures - early next week (April 11 to 17) 

  • There will be a full overnight closure of southbound I-25, with a ramp detour, at the County Line Road bridge Sunday and Friday nights, which will reopen the following mornings.  Then there will be a full overnight closure of northbound I-25, with a ramp detour, in the same area on Monday and Thursday nights and will reopen the following mornings. Closures are necessary to safely set bridge beams, install bridge overhang and set deck panels for reconstruction of the County Line Road bridge.

Full project details on these closures listed below:

16-hour lane and ramp closures on southbound I-25             

  • Travel Impact: Single lane closure along southbound I-25, starting a half-mile north of County Line Road and extending less than one mile to just south of the County Line Road interchange overnight on Saturday. The County Line Road on-ramp to southbound I-25 will be closed Friday night into Saturday morning. The southbound I-25 off-ramp to County Line Road will also be closed Saturday night into Sunday morning.
  • When: 6 p.m. Friday, April 9 to 10 a.m. Saturday, April 10 - on-ramp closure only
  • 7 p.m. Saturday, April 10 to 11 a.m. Sunday, April 11 - single lane and off-ramp closure
  • Why: Crews will replace drainage by connecting the new pipes under I-25. Crews will remove asphalt to install and connect drainage pipes buried more than 10 feet beneath the interstate. Following this work, crews will then replace the asphalt and restore traffic by re-striping the roadway.
  • One lane will be open along southbound I-25 in this area, so drivers are asked to stay the course on I-25 and expect delays. For access to southbound I-25 on Friday night into Saturday morning, head north on I-25, exit and turn around using the Greenland Road interchange and then use the Greenland Road on-ramp to southbound I-25. For access to County Line Road on Saturday night into Sunday morning, continue south on I-25, exit and turn around using the CO 105 interchange and then use the northbound I-25 off-ramp to County Line Road. 
  • Anticipated Delay: 20 minutes

Detour map for Friday night into Saturday morning along Southbound I-25/County Line Road

   Detour map for Friday night into Saturday morning.

Detour map for Saturday night into Sunday morning along Southbound I-25/County Line Road

Detour map for Saturday night into Sunday morning.

Overnight southbound I-25 closures

  • Travel Impact: Full closure of southbound I-25 beneath the County Line Road bridge. Full closure of the County Line Road bridge.  The northbound I-25 off-ramp to County Line Road will also be closed. 
  • When: 8 p.m. Sunday, April 11, to 5 a.m. Monday, April 12. Impacts may begin as early as 6:30 p.m.
  • 8 p.m. Friday, April 16, to 5 a.m. Saturday, April 17. Impacts may begin as early as 6:30 p.m.
  • Why: Construction of the County Line Road bridge over I-25. 
  • Detour: Traffic will funnel into one lane just north of the County Line Road bridge and detour around the closure using the southbound I-25 off- and on-ramps at County Line Road. Access to and from I-25 at County Line Road will be closed. Use the CO 105 interchange (exit 161) for local access. For access to southbound I-25, head north on I-25 and turn around at the Greenland Road interchange (exit 167). See map below.
  • Anticipated Delay: 20 minutes

SB underpass and ramp closures map

Overnight northbound I-25 closures

  • Travel Impact: Full closure of northbound I-25 beneath the County Line Road bridge. Full closure of the County Line Road bridge. The southbound I-25 ramps at County Line Road will also be closed.
  • When: 8 p.m. Monday, April 12, to 5 a.m. Tuesday, April 13. Impacts may begin as early as 6:30 p.m.
  • 8 p.m. Thursday, April 15, to 5 a.m. Friday, April 16. Impacts may begin as early as 6:30 p.m.
  • Why: Construction of the County Line Road bridge over I-25. 
  • Detour: Traffic will funnel into one lane just south of the County Line Road bridge and detour around the closure using the northbound I-25 off- and on-ramps at County Line Road. Use the CO 105 interchange (exit 161) for local access and access to I-25. 
  • Anticipated Delay: 20 minutes

South Gap NB underpass and ramp closures map

Project Information

Travelers are urged to “know before you go.” Gather information about weather forecasts and anticipated travel impacts and current road conditions prior to hitting the road. CDOT resources include:

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 $419 million project also includes shoulder widening, rebuilding bridges, new wildlife crossings, resurfacing with new pavement, improving operations with a southbound I-25 truck climbing lane near Monument and modernizing technology. Project completion is scheduled for November 2022.

Remember: Slow for the Cone Zone

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!