The Most Dangerous Roads in Colorado: A Data-Driven Analysis
Analysis of 155,000+ crash records from CrashStory's database reveals Colorado's deadliest highways, most dangerous cities, and the seasonal and time-of-day patterns that put drivers at risk.
Colorado's roads present unique challenges: mountain passes with steep grades and sharp curves, sudden weather changes that can bring whiteout conditions in minutes, high-altitude sun glare, and rapidly growing population centers that overwhelm aging highway infrastructure. Using CrashStory's database of over 155,000 crash records from January 2023 through July 2024, we analyzed which roads are truly the most dangerous — and why.
Methodology
This analysis uses data from the Colorado Department of Transportation (CDOT) as indexed in CrashStory's database. Our dataset includes 155,000+ crash records spanning January 2023 through July 2024.
We ranked roads using a composite danger score that accounts for total crash count, crashes resulting in injury, crashes resulting in fatality, crash density per mile, and year-over-year trend direction. All data is publicly available and can be explored through CrashStory's dangerous roads rankings and statistics dashboard.
Top 10 Most Dangerous Highways
The following highways account for the highest crash counts and severity in Colorado:
| Rank | Highway | Key Corridor |
|---|---|---|
| #1 | Interstate 25 | Fort Collins to Pueblo |
| #2 | Interstate 70 | Denver to Utah border |
| #3 | US Highway 36 | Denver to Boulder |
| #4 | Interstate 76 | Denver to Nebraska |
| #5 | US Highway 285 | Denver to Fairplay |
| #6 | State Highway 93 | Golden to Boulder |
| #7 | US Highway 6 | Golden to Clear Creek |
| #8 | Interstate 225 | Aurora ring road |
| #9 | State Highway 119 | Longmont to Black Hawk |
| #10 | US Highway 85 | Commerce City to Greeley |
Interstate 25 dominates the rankings, which is not surprising given that it carries over 300,000 vehicles per day through metro Denver and connects the state's four largest cities along the Front Range. View detailed crash data for any highway on our dangerous roads rankings page.
Top 10 Most Dangerous Cities
By total crash count, these Colorado cities see the most accidents:
| Rank | City | County |
|---|---|---|
| #1 | Denver | Denver |
| #2 | Colorado Springs | El Paso |
| #3 | Aurora | Arapahoe |
| #4 | Lakewood | Jefferson |
| #5 | Thornton | Adams |
| #6 | Fort Collins | Larimer |
| #7 | Pueblo | Pueblo |
| #8 | Westminster | Adams |
| #9 | Arvada | Jefferson |
| #10 | Longmont | Boulder |
Explore detailed crash statistics for any Colorado city through our city rankings or browse crashes by county on our crash explorer.
Seasonal Crash Patterns in Colorado
Colorado's crash data reveals distinct seasonal patterns that every driver should understand:
Summer (June–August): Highest Volume
More vehicles on the road means more total crashes. Tourist traffic on I-70 to mountain destinations, construction zone delays, motorcycle season, and long-distance travel all contribute to elevated crash counts. However, crash severity tends to be lower than winter.
Winter (November–March): Highest Severity
While total crash counts drop slightly as some drivers stay home, the crashes that do occur are more severe. Snow, ice, reduced visibility, shorter daylight hours, and mountain pass conditions all increase the likelihood of serious injury or fatal crashes.
Fall Transition (October–November): First Snow Danger
The first major snowfall of the season is consistently one of the most dangerous periods. Drivers have not yet readjusted to winter conditions, summer tires are still on many vehicles, and the combination of falling leaves and moisture creates slippery roads.
Spring (March–May): Unpredictable Weather
Colorado's spring weather is notoriously volatile. March snowstorms followed by 60-degree days create freeze-thaw cycles that damage road surfaces and create potholes. Spring flooding in mountain canyons can close roads without warning.
View real-time and historical crash data by season on our statistics dashboard.
Time-of-Day Risk Analysis
Our data shows clear time-of-day patterns in Colorado crash frequency and severity:
Evening commute. Highest total crash count. Fatigue, congestion, and sun glare.
Morning commute. Second highest crash count. School zones add complexity.
Lower total crashes but highest severity per crash. Impaired and drowsy driving.
Lunch hour traffic spike. Distracted driving from eating, phones.
Fewest total crashes, but those that occur tend to involve high speeds or impairment.
What Makes These Roads So Dangerous
Several factors combine to make Colorado's roads particularly hazardous compared to other states:
- Rapid population growth: Colorado added over 700,000 residents in the past decade, overwhelming road infrastructure designed for far fewer drivers.
- Altitude and mountain terrain: Steep grades, tight curves, rockfall zones, and limited visibility at high elevations create conditions unlike flatland driving.
- Extreme weather variability: Temperatures can swing 50 degrees in a single day. Snow at 9,000 feet and sunshine at 5,000 feet means drivers encounter radically different conditions within a single trip.
- Wildlife crossings: Deer and elk on roadways cause hundreds of crashes annually, particularly on rural highways and mountain roads at dawn and dusk.
- Construction zones: Colorado's roads require constant maintenance and expansion, creating miles of narrowed lanes, shifting traffic patterns, and confused drivers.
- Tourist and recreational traffic: Weekend warrior traffic on I-70 to ski resorts creates massive congestion and chain-reaction accidents on mountain highways.
Safety Tips for Colorado Drivers
Based on our analysis, here are data-informed recommendations to reduce your risk:
Carry proper insurance
MedPay + UM/UIM coverage protects you when others do not.
Avoid 4-7 PM when possible
The evening commute is statistically the most dangerous time to drive.
Winter tires by October
Do not wait for the first snowfall. Colorado law requires adequate traction devices on I-70.
Extra following distance
Colorado conditions change fast. Double your following distance on highways and in mountain areas.
Know your route
Check CDOT road conditions and CrashStory data before unfamiliar mountain drives.
Watch for wildlife
Dawn and dusk on rural highways are peak times for deer and elk crossings.
Stay alert in construction zones
Fines double in active construction zones and crashes are common near lane shifts.
Plan for altitude
Vehicle performance changes at altitude. Braking distances increase and engines work harder on grades.
If you have been in an accident on any of these roads, you can search for your accident in our database, use our settlement calculator to estimate your case value, or find a qualified car accident attorney in your area.
For detailed crash data on any specific road, visit our dangerous roads rankings or explore county-level data on our county rankings page.
Frequently Asked Questions
What is the most dangerous highway in Colorado?
Based on CrashStory's analysis of 155,000+ crash records from January 2023 through July 2024, Interstate 25 (I-25) is the most dangerous highway in Colorado by total crash count, injuries, and fatalities. I-25 runs 300 miles north-south through the Front Range corridor, connecting Fort Collins, Denver, Colorado Springs, and Pueblo — the state's most populated cities.
What time of day are most car accidents in Colorado?
The peak crash hours in Colorado are between 4:00 PM and 7:00 PM, coinciding with the evening commute. A secondary peak occurs between 7:00 AM and 9:00 AM during the morning commute. Weekend nights (10 PM to 2 AM) show elevated crash rates with higher severity due to impaired driving.
Are Colorado roads more dangerous in winter?
Colorado sees distinct seasonal crash patterns. While total crash counts are highest in summer months (more drivers on the road), crash severity is highest in winter months (November through March) due to snow, ice, reduced visibility, and mountain driving conditions. The most dangerous combination is the first major snowfall of the season when drivers have not yet readjusted to winter driving.
Which Colorado city has the most car accidents?
Denver has the highest total crash count by a significant margin, which is expected given its population size. However, when measured on a per-capita basis, several smaller cities along major highway corridors show higher crash rates. Cities at major highway intersections (where I-25 meets I-70, for example) tend to have disproportionately high crash counts relative to their population.
How can I check if a specific road in Colorado is dangerous?
You can use CrashStory's free tools to analyze crash data for any Colorado road. Visit the Rankings section to see dangerous road rankings, or use the crash search tool to find specific accidents on any road. Our county and city pages also provide detailed crash statistics for local roads.
CrashStory Editorial Team
This article is for informational purposes only and does not constitute legal advice. The information is based on Colorado statutes and CDOT data available at the time of writing. Laws and regulations change. Consult a qualified Colorado attorney for advice specific to your situation. Last updated: January 15, 2025.
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