Idaho Fatal Accident Study:

Where Are Idaho’s Deadliest Roads, and What Factors Contribute Most to its Fatal Accidents?

MoneyGeek looked at 640 fatal crashes between 2017 and 2019 to determine the deadliest stretches of road in Idaho. The study analyzed how factors like distracted driving, drunk driving, speeding and time of year contribute to fatal accidents.

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Map of fatal accidents in the state of Idaho

Out of Idaho’s 107,568 miles of road, MoneyGeek analyzed 310 roads to identify which were deadliest to drivers. Several factors contributed to the 640 fatal accidents in Idaho. MoneyGeek’s study looked closely at how four factors — winter conditions, drunk driving, speeding and distracted driving — contributed to deadly crashes. The study also broke down data county-by-county to determine the most dangerous roads there.

Key Findings:

10 Most Dangerous Stretches of Road in Idaho

1. I-84 Between Ustick Rd. and Exit 29

Caldwell
Map of I-84 Between Ustick Rd. and Exit 29

Fatal Accidents: 6

Fatalities: 6

Fatal Accidents Per Mile: 2.3

SR-21 from E. Lake Forest Dr. to Highland Valley Summit

Boise
Map of SR-21 from E. Lake Forest Dr. to Highland Valley Summit

Fatal Accidents: 5

Fatalities: 7

Fatal Accidents Per Mile: 1.2

US-95 from S. McAvoy Rd. to E. Mica View Rd.

Coeur D Alene
Map of US-95 from S. McAvoy Rd. to E. Mica View Rd.

Fatal Accidents: 5

Fatalities: 5

Fatal Accidents Per Mile: 2.7

I-84 from Exit 49 to Exit 42

Meridian | Boise
Map of I-84 from Exit 49 to Exit 42

Fatal Accidents: 4

Fatalities: 7

Fatal Accidents Per Mile: 0.9

US-95 Between Sunnyside Rd. and Cox Rd.

Washington County
Map of US-95 Between Sunnyside Rd. and Cox Rd.

Fatal Accidents: 4

Fatalities: 6

Fatal Accidents Per Mile: 0.8

US-95 from E. Nez Perce Rd. to Hatwai Bypass

Nez Perce County
Map of US-95 from E. Nez Perce Rd. to Hatwai Bypass

Fatal Accidents: 4

Fatalities: 4

Fatal Accidents Per Mile: 1.9

US-95 Between Exit 442 and Boekel Rd.

Kootenai County
Map of US-95 Between Exit 442 and Boekel Rd.

Fatal Accidents: 4

Fatalities: 4

Fatal Accidents Per Mile: 0.8

I-84 Between Exit 188 and Exit 194

Jerome County
Map of I-84 Between Exit 188 and Exit 194

Fatal Accidents: 4

Fatalities: 4

Fatal Accidents Per Mile: 1.1

I-84 Between Exit 13 and Exit 9

Payette County
Map of I-84 Between Exit 13 and Exit 9

Fatal Accidents: 4

Fatalities: 4

Fatal Accidents Per Mile: 0.8

US-93 from E 100 S. to E 290 N.

Jerome County
Map of US-93 from E 100 S. to E 290 N.

Fatal Accidents: 4

Fatalities: 4

Fatal Accidents Per Mile: 0.9

Drunk Driving Involved in 30% of Fatal Accidents

From 2017 to 2019, drunk driving contributed to 30% of all fatal accidents in Idaho. That’s 189 out of 640 fatal crashes. Drunk driving was the primary contributor MoneyGeek studied — it was involved in more fatal accidents than speeding, distracted driving and winter conditions.

You're considered legally intoxicated in Idaho if your blood alcohol concentration (BAC) reaches 0.08%, but it takes very little for your driving to be impaired. A 0.02% BAC measurement is high enough to affect your driving ability, putting yourself and your passengers in danger.

Drunk driving comes with severe consequences outside of fatalities. A DUI conviction leads to increased insurance rates, license suspension, restricted driving privileges and jail time. It will also require you to carry an SR-22 in Idaho, which is more expensive than other types of coverage.

Speeding Is a Factor in 21% of Fatal Crashes

In three years, 136 fatal car accidents in Idaho involved speeding. That’s 21% of all fatal accidents recorded in the state between 2017 and 2019. Driving above the allowable speed limit makes controlling your car more difficult, especially when you need to stop suddenly for any reason. If you get into an accident, your speed increases the strength of impact, which can lead to severe injuries or worse — fatal crashes.

Distracted Driving Contributed to 11% of Fatal Accidents

Distracted driving was a factor in 11% of fatal accidents in Idaho from 2017 to 2019. That’s 73 out of 640 accidents that ended with fatalities. MoneyGeek’s analysis showed Idaho to be the seventh-worst state for distracted driving. In July 2020, Idaho enacted a new distracted driving law that expanded its definition of distracted driving beyond texting to include other uses of gadgets such as browsing social media and watching or recording video.

July Had More Fatal Accidents Than Any Other Month

MoneyGeek found that 12.7% — or 83 accidents — in Idaho happened in July. June had the second-highest number of lethal accidents with 75 (11.9%), and August third with 73 (11.4%). These months all fall within the state’s 100 Deadliest Days, the period with the most fatal accidents that spans from Memorial Day to Labor Day. Drunk driving was the most sizable contributing factor to fatal accidents in all three months.

Average Fatal Accidents By Month: 2017–2019
Month
Fatal Accidents
Drunk Driving Related
Distracted Driving Related
Winter Conditions
Speeding Related
% of Total

January

26

6

2

1

5

3.7%

February

36

8

4

7

10

6.0%

March

30

8

6

1

6

4.7%

April

47

16

3

0

9

7.0%

May

61

18

7

1

8

10.1%

June

75

23

9

0

12

11.9%

July

83

24

9

0

15

12.7%

August

72

24

5

0

19

11.4%

September

59

19

8

0

10

9.2%

October

61

14

10

1

17

9.2%

November

38

12

5

4

11

6.3%

December

52

17

5

5

14

7.8%

Driving Safely Protects You, Others and Your Wallet

Being a safe driver is an advantage in many ways. Not only do you make Idaho roadways less dangerous, but you may also pay fewer costs in the future. However, even the most careful drivers can be involved in auto accidents, so it’s essential to have proper insurance coverage.

Full coverage car insurance is the best type of policy to carry for financial protection in Idaho. Because Idaho is a tort state, you’re obligated to shoulder the other driver’s medical and repair expenses if you cause an accident. A full coverage policy covers these damages and also protects you from costs incurred if you or your passengers suffer injuries, or your car is damaged.

You can purchase full coverage car insurance in Idaho for an average of $745 per year. While drivers in Boise pay the same amount per year on average, note that the price of car insurance can vary depending on where you live in the state.

Policy rates are also affected by other factors such as your age, driving history or preferred coverage level. It’s best to compare quotes from multiple providers to help you find car insurance companies with the cheapest rates.

Fatal Accidents and Most Dangerous Roads: County Breakdown

The top-five counties in Idaho with the most fatal accidents had 251 fatal crashes from 2017–2019. That's 39% of all recorded accidents that resulted in fatalities. Approximately 28% (70) involved drunk driving, 22% (54) speeding and 9% (23) distracted driving.

Of the 43 counties in Idaho, Ada had the highest number of fatal accidents in the three-year period at 78. Most of these happened along I-84 and involved drunk driving and speeding accidents.

Fatal Accidents and Contributing Factors By County: 2017–2019
County
Fatalities
Fatal Accidents
Drunk Driving Related
Distracted Driving Related
Speeding Related
Most Deadly Road (Fatal Accidents)

Ada

90

78

24

10

22

I-84 (9)

Canyon

71

66

16

5

7

I-84 (10)

Kootenai

52

51

15

7

15

US-95 (15)

Bonneville

32

30

7

1

9

US-26 (5)

Bannock

30

26

8

0

1

I-15 (10)

Jerome

30

26

10

8

0

I-84 (9)

Elmore

25

25

8

2

6

I-84 (14)

Twin Falls

26

23

5

5

1

US-93 (7)

Nez Perce

22

22

5

1

8

US-95 (7)

Bonner

24

22

6

3

9

US-95 (5)

Bingham

23

21

6

4

2

I-15 (7)

Boise

16

16

6

1

4

SR-55 (6)

Idaho

20

16

5

3

2

US-95 (7)

Blaine

18

14

5

2

6

SR-75 (5)

Shoshone

14

14

5

2

4

I-90 (6)

Minidoka

14

14

4

3

5

I-84 (4)

Valley

15

13

3

0

4

SR-55 (6)

Payette

11

11

3

1

2

I-84 (5)

Gooding

12

11

5

0

2

SR-46 (4)

Latah

10

10

3

0

5

SR-8 (4)

Cassia

11

10

4

5

1

I-84 (2)

Fremont

13

10

4

0

3

US-20 (5)

Jefferson

10

10

4

2

2

I-15 (3)

Washington

10

8

1

2

0

US-95 (6)

Adams

11

8

1

0

1

US-95 (7)

Lincoln

9

7

2

0

1

SR-24 (3)

Owyhee

7

7

5

0

3

SR-78 (3)

Oneida

8

7

1

0

0

I-15 (5)

Benewah

7

6

2

0

1

SR-3 (2)

Franklin

7

6

3

0

1

US-91 (4)

Gem

6

6

1

1

0

SR-16 (2)

Madison

5

5

0

1

1

US-20 (3)

Lewis

5

5

1

0

0

US-12 (3)

Power

5

5

1

1

2

I-86 (2)

Custer

5

5

2

1

0

US-93 (2)

Caribou

6

5

2

0

1

SR-34 (2)

Lemhi

5

4

0

0

1

US-93 (1)

Boundary

4

4

1

1

1

US-95 (4)

Butte

3

3

1

0

0

US-20 (1)

Teton

4

3

1

1

1

SR-33 (2)

Bear Lake

3

3

1

0

0

US-89 (2)

Clark

2

2

0

0

1

I-15 (2)

Clearwater

2

2

2

0

1

SR- Old Sr 7Gilbert Grade Rd (1)

About the Author


expert-profile

Doug Milnes is the head of marketing and communications at MoneyGeek. He has spent more than a decade in corporate finance performing valuations for Duff and Phelps and financial planning and analysis for various companies including OpenTable. He holds a master’s degree in Predictive Analytics (Data Science) from Northwestern University and is a CFA charter holder. Doug geeks out on building financial and predictive models and using data to make informed decisions.


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