This is the deadliest route in Idaho. It’s a popular, well-traveled road north of Boise

EAGLE (Idaho Statesman) — Idaho Highway 55, a heavily traversed road between Eagle and McCall north of Boise, has been identified as the deadliest route in Idaho.

A recent study conducted by Texas-based legal team The Barber Law Firm analyzed data from the National Highway Traffic Safety Administration to find the deadliest roadways in every state. Data was pulled from the NHTSA’s Fatality Analysis Reporting System to find the average number of fatalities between 2018 and 2022.

Idaho’s Highway 55 is a twisting road that spans about 148 miles from where it starts in east Marsing at the junction with U.S. 95 until it meets up with 95 again at New Meadows. It tracks along the Payette River before plunging into the Idaho Batholith, an extensive range of granite rock formations up to 97 million years old.

“It’s quite a dramatic landscape…and a hazard in terms of the stability of the slopes and the rocky outcrops,” Claudio Berti, state geologist and director of the Idaho Geological Survey, previously told the Idaho Statesman. “It’s a very, very challenging stretch of the road.”

HOW DEADLY IS IDAHO 55?

Over the five years measured, Idaho 55 saw an average of 8.2 fatalities per year. That total nearly doubles the next-nearest deadly route, Idaho 75 through the Sawtooth Valley, which averages 4.2 deaths per year.

Idaho 55 has already witnessed one death this summer after a vehicle veered into the Payette River. It was unclear how many people were in the car, but one person died, according to the Boise County Sheriff’s Office.

Here are Idaho’s other deadliest roads and how many deaths per year it sees on average:

1. Idaho Highway 55 (8.2) – Between Marsing and East Meadows along the Payette River
2. Idaho Highway 75 (4.2) – Through the Sawtooth Valley in central Idaho
3. Idaho Highway 21 (3.4) – Between Boise and Stanley along the boundary of the Sawtooth Mountains
4. Idaho Highway 33 (2.8) – Eastern Idaho from U.S. Highway 20, through Rexburg and toward Wyoming Highway 22 and Teton Pass
5. Idaho Highway 22 (2.2) – A 44-mile state highway in eastern Idaho between Idaho 33 and Dubois

RECENT IMPROVEMENTS TO IDAHO 55

Idaho 55 has been scrutinized for many years. The ancient rocky outcrops along the highway are susceptible to crumbling landslides, and even minor seismic activity can send large boulders crashing onto the roadway below.

A one-mile stretch of Idaho 55 near Smiths Ferry is considered particularly deadly. Between 2001 and 2021, there were 154 crashes on the one-mile stretch, over half of which resulted in injuries and several deaths, according to previous Statesman reporting.

Idaho Transportation Department officials call it the “white-knuckle section” of the highway.

The portion of the highway near Smiths Ferry recently underwent a $62.8 million construction project to straighten curved portions, widen shoulders, and add guardrails to improve safety. Construction crews returned in the second half of 2023 to stabilize a hillside that dropped about 70,000 tons of rock and debris onto the roadway.

The project’s original cost was $30.8 million, but concerns over possible avalanches and other safety issues ended up doubling the price tag — and delaying completion.

“The adjustments we have made in the field acknowledge how much we put a premium on safety,” ITD spokesperson Vince Tromboli previously told the Statesman. “We want to make sure this road is as safe as possible. And so in the name of ensuring the safety of the traveling public, yeah, we had to spend more money.”