The Most Dangerous Highway in Every State

Every interstate has risks, but some stand out for a far higher concentration of fatal crashes than others. Using the most recent fatal crash data from the NHTSA Fatality Analysis Reporting System and interstate mileage data from the Federal Highway Administration, we calculated fatal crashes per 20 miles of highway in each state. We also calculated fatal crashes per 100 miles for interstates nationwide. Together, these calculations show the most dangerous highway in every state and the most dangerous highways in the US overall.

Key Findings

• I-45 in Texas is America’s most dangerous interstate, with 18.95 fatal crashes per 100 miles in 2024—about 25% higher than second-place I-4 in Florida.
• Florida’s stretch of I-95 had the highest fatal-crash total for any interstate within a single state, with 100 fatal crashes in 2024. I-95 was also the deadliest interstate in seven states overall.
• California is the most dangerous state to drive through by interstate fatal-crash rate, with 19.61 fatal crashes per 100 miles; Texas recorded the highest total number of fatal interstate crashes, at 545 in 2024.
• Texas features prominently in the national ranking: seven of the nation’s 20 most dangerous interstates pass through Texas.

The Most Dangerous Highway in Every State

Connecticut’s I-91, which runs from New Haven through Hartford to the Massachusetts border, had the highest fatal-crash rate of any interstate in this analysis, with 18 fatal crashes—or 6.21 per 20 miles of highway. That was nearly 19% higher than Florida’s I-95, which ranked second by rate. In early 2024, Connecticut officials identified busy stretches of I-91 and I-95 as priorities for stepped-up highway-safety enforcement amid a rise in roadway fatalities.

Florida’s stretch of I-95 stands apart for its sheer number of fatal crashes. The highway saw 100 fatal crashes in Florida in 2024, the highest total recorded for any interstate within a single state in this study, alongside a rate of 5.23 fatal crashes per 20 miles. I-95 is also the interstate most likely to appear as a state’s deadliest route: it topped the list in seven states—Delaware, Florida, Maine, New Hampshire, Pennsylvania, Rhode Island, and Virginia.

Several other interstates repeatedly emerge as the most dangerous within the states they cross. I-35 ranked first in Iowa, Kansas, and Oklahoma; I-80 did the same in Nebraska, New Jersey, and Wyoming; and I-90 topped the list in Montana, South Dakota, and Wisconsin. I-10 was the most dangerous interstate in both Arizona and California, while I-85 led in Alabama and North Carolina. These recurring routes show how risk can follow a major corridor across state lines, even as each state’s fatal-crash rate differs.

The Most Dangerous Highways in the US

These are the 10 most dangerous interstates in America:

1. I-45 – 18.95 fatal crashes per 100 miles
2. I-4 – 15.12
3. I-5 – 12.31
4. I-24 – 12.01
5. I-85 – 11.71
6. I-30 – 11.45
7. I-95 – 11.07
8. I-17 – 10.98
9. I-10 – 10.69
10. I-65 – 9.35

The country’s most dangerous highway is I-45 in Texas, which recorded 54 fatal crashes in 2024—or 18.95 per 100 miles of highway. The route runs between the Houston and Dallas-Fort Worth areas, and its fatal-crash rate was about 25% higher than that of second-place I-4 in Florida. I-4, a major cross-state route connecting the Tampa Bay, Orlando, and Daytona Beach areas, had 20 fatal crashes and a rate of 15.12 per 100 miles.

Longer interstates also appear prominently in the ranking. I-5, which runs from the Mexican border through California, Oregon, and Washington to the Canadian border, had 170 fatal crashes in 2024—the third-highest rate at 12.31 fatal crashes per 100 miles. I-24 followed with 38 fatal crashes and a rate of 12.01 per 100 miles across Illinois, Kentucky, and Tennessee, while I-85 recorded 78 fatal crashes as it passes through five Southeastern states: Alabama, Georgia, South Carolina, North Carolina, and Virginia. 

I-95, the East Coast’s main north-south artery, ranked seventh with 213 fatal crashes, or 11.07 per 100 miles. The route spans roughly 1,900 miles and supports substantial passenger and truck traffic along the Eastern Seaboard. I-65 rounded out the top 10 with 83 fatal crashes and a rate of 9.35 per 100 miles across Alabama, Tennessee, Kentucky, and Indiana.

Our home state, Texas, is a major throughline in America’s most dangerous highways: seven of the nation’s 20 highest-risk Interstates pass through the state. It is also home to the country’s most dangerous route, I-45, which is entirely within Texas. For a closer look at the routes that ranked highest within the state, see Hartley Law’s analysis of the most dangerous interstates in Texas. 

The Southeast also features heavily in the ranking. Six of the 10 most dangerous interstates—I-4, I-24, I-85, I-95, I-10, and I-65—pass through at least one Southeastern state, including Florida, Alabama, Georgia, Tennessee, Kentucky, and the Carolinas. 

The Most & Least Dangerous States to Drive Through

These are the 10 most dangerous states to drive through based on fatal crashes on interstates: 

1. California – 19.61 fatal crashes on interstates per 100 miles
2. Florida – 17.63
3. Maryland – 16.04
4. Texas – 15.13
5. Georgia – 14.36
6. New Jersey – 13.45
7. Connecticut – 12.71
8. Tennessee – 12.69
9. Arizona – 12.66
10. North Carolina – 11.90

California ranked as the most dangerous state for interstate driving, with 482 fatal crashes across its interstate system in 2024—or 19.61 fatal crashes per 100 miles. Florida followed at 17.63 crashes per 100 miles. 

Texas recorded more fatal crashes on its interstates than any other state: 545 crashes in total. But because Texas has a far more extensive interstate network, its fatal-crash rate fell to 15.13 per 100 miles, placing it fourth overall. Arizona ranked ninth overall for 12.66 fatal crashes per 100 interstate miles, in part because it is crossed by two of the country’s 10 most dangerous interstates: I-17, which ranked eighth nationwide, and I-10, which ranked ninth.

The top 10 includes both large, heavily traveled states and smaller states with more compact interstate networks. Four Southern states—Florida, Georgia, Tennessee, and North Carolina—made the list, while Maryland, New Jersey, and Connecticut show that the highest fatal-crash rates are not limited to the country’s largest states.

What These Interstate Crash Rates Mean for Drivers

These results cannot explain why any individual crash occurred, but they make it easier to see where fatal crashes are most concentrated. By comparing crash totals with interstate mileage, this study highlights the routes and states where drivers may face an elevated risk, and where continued road-safety improvements, enforcement, and driver caution are especially important. The next step is not to avoid the most dangerous roads, but to approach every trip with care: wear a seat belt, avoid distractions, slow down when conditions call for it, and never drive impaired.

If you’ve been injured in a crash in Dallas or the surrounding area, Hartley Law’s car accident attorneys can help you understand your legal options. The firm represents injured drivers and passengers and can assist with investigating the crash, preserving evidence, and communicating with insurance companies while you focus on recovery.

Methodology

We analyzed the most up-to-date fatal car-crash records (2024) from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS) to identify the most dangerous Interstate in each state. 

We obtained each Interstate’s total mileage within a state from the Federal Highway Administration. For every Interstate, we counted fatal crashes recorded on that route within the state in 2024, then divided the total by the route’s mileage in that state and multiplied by 20 to calculate fatal crashes per 20 miles. The Interstate with the highest rate in each state was named that state’s most dangerous highway. 

Interstates that cover fewer than 10 miles within a state were excluded from that state’s analysis. Alaska was also excluded because its interstate highways are unsigned, and FARS data does not consistently identify crashes using the state’s interstate route designations.

To find the most dangerous interstates in America, we totaled the number of fatal crashes recorded on each Interstate across all states it traverses in 2024. We then combined each Interstate’s in-state mileage and calculated fatal crashes per 100 miles. Routes were ranked from highest to lowest based on that rate. Interstates spanning fewer than 100 miles nationwide were excluded from this ranking.

Fair Use

You are welcome to use, reference, and share non-commercial excerpts of this study with proper attribution. If you cite or cover our findings, please link back to this page so readers can view the full methodology, charts, and context.