When I-25 stops,
Castle Rock shouldn't.
I-25 is the backbone of Castle Rock's transportation system. When it shuts down, the problem does not stay on the interstate — it spills onto our roads, our intersections and into our neighborhoods.
My approach is simple: keep I-25 open whenever it can safely remain open. When a full closure is unavoidable, activate a preplanned, controlled detour designed to keep Castle Rock moving.
Two problems. Two responses.
Keep I-25 open.
Coordinate with state and local agencies before the next major incident so full closures are avoided when safely possible and lanes reopen as quickly as conditions allow.
Control the detour.
When the interstate has to close, activate one official through-route for that closure, retime signals and keep diverted interstate traffic on major roads instead of neighborhood streets.
I-25 closes. Everybody improvises.
When a major incident closes I-25, thousands of drivers begin looking for another way through Castle Rock. Navigation apps send vehicles toward whatever route appears fastest at that moment. The result can be traffic spreading across multiple local corridors at the same time.
Instead of allowing the entire town to become the detour, Castle Rock should have a response ready before the closure happens.
Prevent the shutdown when we can.
Safety comes first. But a full interstate closure should be the last option, not the automatic one.
Castle Rock does not control I-25. That makes coordination more important, not less. The Town should have a standing incident plan with the agencies that respond when something goes wrong on the interstate.
The goal is not to second-guess responders at the scene. The goal is to do the work ahead of time so responders have the contacts, resources and traffic plan needed to protect people while restoring traffic as quickly as possible.
Create a standing I-25 incident playbook.
Bring Castle Rock, CDOT, Colorado State Patrol, Douglas County, Police, Fire and Public Works together around one written plan: who gets called, who makes each decision and what happens next.
Keep a lane open when it is safe to do so.
Build the plan around maintaining some interstate capacity when responders determine conditions allow it, rather than treating every major incident as an all-or-nothing closure.
Reopen lanes in stages.
When part of the roadway can safely be released, reopen it. Castle Rock should advocate for restoring usable capacity as soon as responders can do so safely instead of waiting for the entire incident to be completely finished.
Have clearance resources ready.
Major crashes, disabled commercial vehicles and hazardous materials require specialized equipment. The response plan should identify heavy-recovery, hazmat and traffic-control resources before they are needed.
Learn from every major closure.
After a significant shutdown, review what happened: how long lanes were closed, what delayed reopening, where local traffic failed and what should change before the next incident.
One plan. Not a thousand shortcuts.
When I-25 really has to close, the detour should already be decided.
A full closure will sometimes be unavoidable. During those incidents, Castle Rock should switch immediately from normal traffic operations to an emergency traffic plan.
Each major I-25 closure scenario should have a predesignated primary route for interstate through-traffic. That route becomes the focus of signal timing, signage, traffic control and public communication until interstate lanes reopen.
Predesignate the route.
Map a primary detour for each likely closure location and direction. The route should be chosen before the emergency — based on capacity, intersections, emergency access and the ability to keep traffic away from residential streets.
Warn drivers before they reach Castle Rock.
Coordinate upstream messaging so interstate drivers know about the closure and official detour before they arrive at the backup and begin searching for their own route through town.
Put signals into emergency mode.
Pre-program signal plans for major closure scenarios. When a detour is activated, give the designated corridor more green time and coordinate intersections to move the surge through town instead of managing every signal independently.
Control the critical intersections.
Use police, traffic personnel, portable signs and temporary traffic-control devices where they are needed most to prevent blocked intersections, conflicting movements and additional gridlock.
Protect neighborhood streets.
Local residents still need to get home and emergency vehicles still need access. The objective is to keep diverted interstate through-traffic on the designated major corridor instead of allowing residential streets to become unofficial highways.
A response everyone already understands.
Crash, hazmat event or other major disruption.
Responders secure the scene and determine what can safely remain open.
If a lane can safely remain open, keep traffic moving.
If a full closure is required, turn on the preplanned detour.
Retimed signals, signs and traffic control keep the route moving.
Restore interstate lanes as soon as responders determine it is safe.
This plan should exist on a normal Tuesday.
An emergency is the worst time to introduce people, choose a route or decide how signals should operate. Those decisions should already be made, tested and ready to activate.
Formalize the partnership.
Direct Town staff to establish a recurring I-25 incident-planning process with CDOT, CSP, Douglas County and the Town's public-safety and transportation teams.
Map the closure scenarios.
Identify the likely northbound and southbound closure segments, the primary detour for each and the intersections most likely to fail under diverted traffic.
Pre-program the signals.
Build emergency timing plans that can be activated quickly instead of trying to redesign traffic flow while vehicles are already stacking up.
Practice it.
Run tabletop exercises and test the communications chain so every agency knows its role before a real closure puts the plan under pressure.
Measure the result.
Track closure duration, time to activate the detour, corridor travel times and problem intersections. Improve the plan with real data after every major event.
We do not own I-25. We do own our response.
I-25 is a state highway. Castle Rock Town Council cannot order CDOT or the State Patrol to keep a highway lane open.
Council can set a priority for Town staff, strengthen intergovernmental coordination, make sure Public Works, Police and Fire have a shared response plan, support the signal and traffic-control tools needed locally and insist that Castle Rock is at the table when interstate incident procedures are developed.
Castle Rock already has many of the pieces. The work is connecting them into one clear plan that can be activated quickly when I-25 fails.
Recent incidents show how quickly trouble on I-25 becomes a Castle Rock traffic problem.
Fatal I-25 crash causes major traffic delays across the area
A prolonged interstate shutdown pushed traffic onto alternate routes and left residents dealing with major delays.
Read the storyHazmat incident blocks northbound I-25 lanes in Castle Rock
A crash and diesel spill near Castle Rock Parkway reduced interstate capacity and backed traffic through the area.
Read the story
Keep I-25 moving when we can.
Keep Castle Rock moving when we can't.
Where does traffic break down for you?
If you live with one of these backups, you probably know the problem intersections and neighborhood cut-throughs better than anyone. I want to hear what you see when I-25 shuts down.
