New Data Shows Idaho’s 15 Deadliest Roads Ahead of Summer Travel Season

Driving on Idaho’s roads can be an absolutely beautiful and picturesque experience. It’s much better when you’re the passenger. While you’re behind the wheel in the Gem State, you need to be focused because there are a number of things that could lead to a potential accident. 

Since 2008, Idaho has experienced at least 3,491 fatal crashes resulting in 3,851 deaths. The Idaho Transportation Department maintains a detailed, searchable database of Idaho traffic crashes from the past 17 years.

The Top 5 Causes of Fatal Crashes in Idaho

According to their data, the #1 contributing circumstance to fatal accidents are the result of someone making the poor decision to get behind the wheel while under the influence of alcohol. Alcohol was a circumstance in 1,009 of those fatal crashes. 

READ MORE:  The Deadliest Time to Drive in Boise and 10 Other Idaho Cities 

Failing to maintain your lane, inattention, drug impairment and driving too fast for conditions rounded out the top five. 

What Are the 100 Deadliest Days in Idaho?

As we’re sitting down to write this, Idaho is entering what’s known as the “100 Deadliest Days.” If you’re unfamiliar with the term, that’s the period of time between Memorial Day and Labor Day where deadly crashes spike in Idaho. The timing makes sense, because in the summer months more Idahoans are enjoying cookouts and parties where alcohol is served, teen drivers are out of school for the summer and people stay out later because there’s more daylight. 

Idaho’s 15 Deadliest Roads Revealed

As we head into the “100 Deadliest Days” it’s a good idea to familiarize yourself with Idaho’s danger zones. Which roadway do YOU think is the deadliest? 

It may depend on where you live. I live in Boise, Idaho’s largest city, so I would’ve assumed it would be I-84 since it is the major roadway that the majority of people in the area use for their daily commute. After I looked at ITD’s searchable database, I realized I was partially right. 

Why US-95 Is Considered Idaho's Most Lethal Road, Not I-84

From 2008 to today, I-84 has been the site of the MOST fatal crashes with 287 reported. However, US-95, the major roadway that will take you from the outskirts of the Boise metro all the way to North Idaho and on to the Canadian border, has actually claimed more lives. Over the past 17 years, 281 crashes on US-95 resulted in 326 deaths. 

Which Idaho Roads Have the Most Fatal Wrecks?

Here’s a look at the 15 most deadly roads from 2008 through May 2025.