The Idaho Office of Highway Safety released preliminary data on September 16 showing an increase in traffic fatalities during the summer months. Ninety people died in crashes across the state between Memorial Day and Labor Day, up from 88 deaths recorded during the same period in 2025.
State officials refer to this three-month window as the “100 Deadliest Days” due to historically higher crash rates associated with increased travel volume. While the summer spike represents a slight increase year-over-year, the broader annual trend shows improvement. Year-to-date traffic fatalities in 2026 stand at 150, compared to 174 at the same point last year.
Regional Breakdown of Fatalities
Ada County recorded the highest number of fatal crashes during the summer period, with 13 deaths. Given Ada County’s estimated population of 557,000, it remains the most populous area in the state and sees significant traffic volume.
Bonneville County followed with 10 crash deaths. With an approximate population of 123,000, Bonneville County saw a notable number of fatalities relative to its size.
In North Idaho, Bonner County recorded eight deadly crashes. The county has a population of roughly 54,400. Canyon County reported seven fatalities, while Idaho and Kootenai counties each recorded six deaths during the summer stretch.
Bonner County Summer Traffic Deaths Reach Third-Highest Total in Idaho
Primary Causes of Crashes
State data identifies several recurring factors contributing to fatal accidents. The top causes include failure to wear seat belts, drivers failing to maintain their lane or crossing the centerline, and impairment from alcohol or drugs.
Inattentive driving and excessive speed also rank among the leading contributors. Additionally, failure to obey traffic signs and signals remains a critical factor in crash severity.
Safety Campaigns Continue
Josephine Middleton, Idaho Highway Safety Manager, emphasized the lasting impact of these tragedies on families. She noted that every death leaves permanent consequences for those left behind.
“Every one of these deaths impact their families forever,” Middleton said.
The Office of Highway Safety continues to run SHIFT Idaho safety campaigns aimed at reducing crash rates. Officials are urging motorists to prioritize defensive driving habits as the state approaches the end of the calendar year.
Middleton outlined specific actions drivers can take to reduce risk on the road. “We can save lives and prevent serious injuries by consistently choosing safety first: buckle up, stay focused, drive sober and slow down,” she said.
The data release comes as state agencies navigate budget constraints following legislative decisions earlier in the year.