America’s most dangerous winter roads

Winter doesn’t just change how the roads look—it changes how they behave, turning seemingly safe pavement slick within seconds  as temperatures drop faster than roads can adapt. In fact, winter weather contributes to nearly 20% of weather-related crashes nationwide, according to the Federal Highway Administration.

Consequences in the commercial space extend far beyond the sole vehicle or driver that’s part of the fleet. In crashes involving large trucks, about 70% of the people killed and roughly 72% of those injured are occupants of other civilian vehicles.

During the holiday and winter season, the risk to passenger-vehicle occupants further increases. Thanksgiving travel brought roughly 70 million people onto U.S. roads in 2024, and just a few weeks later, more than 100 million traveled by car around Christmas and New Year’s. This surge puts significantly more passenger vehicles in close proximity to heavy trucks. 

Extended darkness during the winter months also play a role—nighttime fatal crash rates are 3x higher than daytime—and road surface conditions can deteriorate quickly as temperatures drop.

To understand how seasonal shifts translate into safety incidents and accidents, we analyzed anonymized operational data from Samsara’s Connected Operations Platform across 2022–2025. The results show a consistent pattern: crash risk increases in winter, independent of fleet size or industry. The conditions themselves introduce more exposure, meaning each mile driven in winter carries inherently higher risk than the same mile driven in spring or summer.

Seasonal breakdown: Crashes per mile climb in winter

Commercial drivers log more miles in spring than any other season, but those miles are statistically safer. In winter, the story shifts: Drivers travel slightly less, but experience about 7% more crashes per 1 million miles. That difference may seem small—but has large implications at scale. Here’s how this breaks down by season:

In other words, winter risk isn’t about how much we drive, but how hazardous each mile becomes. The seasonal differences in crashes show how exposure and environmental severity interact differently across the year.

The winter holiday season

During the week of Thanksgiving, many shippers scale back operations and drivers take time off, reducing the number of trucks on the road and, correspondingly, lowering the total volume of commercial crashes that week.

But fewer commercial crashes doesn’t necessarily mean safer roads. Last Thanksgiving, as passenger vehicle volume surged during the holiday week, the commercial crash rate per mile rose 13%.

Thanksgiving Week vs. Prior Week (M–F 2024)

This culminated in a distinct spike on the Sunday after Thanksgiving (+65%), driven by the confluence of fleets ramping back up merging with the single busiest travel day of the year.

Return-to-Road Spike (Sunday, 2024)

When danger peaks

Winter crash risk is highest in the afternoon and evening commute windows, when together they account for nearly half of all crashes and traffic is heaviest. Congestion, changing pavement temperatures, and the transition from daylight to darkness combine to shrink reaction time. Nighttime hours remain especially risky as temperatures drop and visibility worsens, while late-night and early-morning periods still see serious crashes driven by fatigue and black ice.

Top states for winter crash rate increases

Some states—such as Wyoming, New Mexico, and Montana—have elevated commercial crash rates year-round. However, winter conditions amplify crash risk most sharply in states where long-haul freight corridors intersect with rapidly changing weather conditions. From fall to winter, crash rates increased 168% in North Dakota, 65% in Mississippi, and 50% in Kentucky, with significant spikes also observed in Minnesota, Michigan, and Iowa. These states share a common pattern: high-speed rural or interstate roadways combined with early-season freeze and variable pavement conditions, which create abrupt exposure changes for commercial drivers.

Geographical risk patterns shift dramatically—some small-mileage northern and rural states show rates 2–3x higher than national averages, even if their total crashes are modest.

• High-population states (like Texas or California) dominate in absolute crashes.

• Low-mileage, high-hazard states (like North Dakota or Minnesota) dominate in per-mile risk.

Regional patterns

• Upper Midwest: North Dakota, Minnesota, Iowa, and Michigan show the steepest crash rate increases, tied to snowpack, ice storms, and heavy long-haul traffic.

• Appalachia & South: Kentucky and Mississippi exhibit sharp rises due to intermittent freeze–thaw events and limited salting infrastructure.

• West & Mountain States: Nevada and Colorado see rate gains linked to night-time black ice and high-altitude corridors.

• Northeast: New York and Massachusetts show smaller but consistent winter upticks, offset by strong plowing and driver familiarity.

The most dangerous winter roads in America

Winter crash risk isn’t evenly spread across highways—it concentrates in a handful of brutal segments. The worst clusters show up on I-70 over Colorado’s high passes, I-80 across Elk Mountain in Wyoming, the Newark Bay stretch of the New Jersey Turnpike, I-40 at West Memphis over the Mississippi, and lake-effect and interchange zones on I-90 near Buffalo/Syracuse and I-80 through Des Moines. 

What ties these hotspots together? Rapid temperature swings and wind exposure on elevation and bridges, plus dense metro interchanges where freight and passenger traffic coalesce—conditions that can strip pavement friction in minutes. In these heightened-risk environments, a small loss of traction or visibility can quickly escalate into multi-vehicle incidents involving both trucks and passenger cars.

Here are the U.S. roadways that show the largest increases in crash rate during winter, as compared to fall:

A connected approach to safer roads

Winter road conditions change faster than drivers can respond—pavement friction can drop within minutes as temperatures fall, and visibility declines earlier and more sharply. To balance out seasonal effects and operate a program anchored in safety, fleets need to shift incident response from reactive to preventative.

1. Increase real-time in-cab coaching: Use in-cab alerts to help drivers adjust in the moment when road or visibility changes occur.

2. Continuously monitor weather and road conditions: Use Weather Intelligence and StreetSense to track changing conditions at the street level and alert drivers before they enter severe weather or black ice zones.

3. Expand visibility around the vehicle: AI dash cams and multi-cam setups provide 360-degree awareness, critical during longer dark hours and snow, rain, or fog.

4. Coach ahead of the risk curve: Samsara surfaces patterns in risky driving behavior so fleets can coach before these patterns escalate into incidents.

5. Proactively adjust operations: Use operational data to reroute, re-time trips, reduce schedules, or shift workloads when conditions deteriorate.

Seasonal solutions 

Moving from awareness to preventative action

Taking the following actions produces a step-change in how organizations manage winter operations:

1. Identify high-risk roadways and corridors using segment-level StreetSense™ scoring

2. Re-route or re-time trips based on Weather Intelligence forecasts

3. Real-time in-cab coaching for drivers most exposed to night or freeze conditions

4. Trigger operational changes (pretreatment, chain-up protocols, shift adjustments) before conditions cross thresholds

The result is not just fewer crashes, but fewer delays, fewer emergency responses, fewer claims, and fewer out-of-service vehicles when fleets are needed most. Understanding these patterns, and acting on them before exposure, is what truly reduces winter risk at scale.

To learn more about how Samsara safeguards against winter weather risks, visit Samsara's Weather Intelligence.