stories
stories
HomeMoneyLifestyleNewsSportsEntertainmentTravelScienceLocal

When and where do fog-related fatal crashes occur most often?

·Brian Beltz for 1point21 Interactive

Canva
Canva
Add Stacker as Preferred Source

On October 23, 2023, an unusually dense combination of smoke and fog shrouded the New Orleans area, creating dangerous driving conditions on many Louisiana roads. The "super fog" eventually led to a devastating 158-vehicle chain-reaction crash on Interstate 55 that killed eight people.

Just days later, super fog blanketed the area again and caused another deadly crash on Interstate 10.

While super fog is a relatively rare weather phenomenon, fog that impacts visibility and safety on the road is not, especially during the late fall and winter months. From 2001 to 2021, there were a total of 8,410 fatal crashes on U.S. roadways when fog was present, nearly 30 percent of which occurred in December and January.

When and where do fog-related fatal crashes occur most often? How can drivers keep themselves and other motorists safe?

Hill Law Firm analyzed over 700,000 fatal crash records from the National Highway Traffic Safety Administration (NHTSA) to find the answers.

Key findings

  • During the observation period, foggy conditions were only present in a little over one percent of all fatal collisions. However, that rate nearly doubled (2.2 percent) in December and January, accounting for 2,504 of the 8,410 fog-related crashes.
  • They are more likely to occur during early morning hours — with 38 percent between the hours of 5 a.m. and 8 a.m.
  • While fog-related fatal crashes are most common in Texas (971) and California (755), they are most prevalent in West Virginia and Oregon.
  • More fog-related fatal crashes happen on California State Route 99 than any other road or highway in the country, with 43 crashes that killed 53 people.
  • Crashes in these conditions are more likely to be in rural areas. In fact, 64 percent of fatal crashes in foggy conditions occurred on rural roads, compared to 44 percent for all other fatal crashes.
heat chart showing crashes in fog conditions most likely to happen in early morning hours

Hill Law Firm

1 / 4

When do these crashes occur?

Fatal fog crashes are most likely to occur in the early morning hour – peaking between 5 am and 8 am. While fog typically forms overnight, the morning rush hour period exposes many more motorists to dangerous conditions.

A bar graph of Fatal fog crashes peak in December and January

Hill Law Firm

2 / 4

Nearly 1 in 3 of all fatal fog crashes occur across just two months

While the foggiest times of year vary from region to region, December and January are the deadliest months by far. In fact, 30 percent of all fatal fog crashes occur during these two months and the rate of fog-related crashes increases by nearly double.

Where do these crashes occur?

Any time fog develops and impacts visibility, it creates a potentially dangerous road condition. However, some roads, counties, and states see more fog and fatal crashes than others.

By roadway

During the observation period, eight roadways saw 20 or more fatal fog crashes. Three of those roads were in California, two in both Texas and Florida, and one in Louisiana.

  • SR-99 in California: 43 crashes
  • I-10 in Texas: 32 crashes
  • US-101 in California: 32 crashes
  • US-27 in Florida: 31 crashes
  • I-75 in Florida: 31 crashes
  • I-5 in California: 26 crashes
  • US-59 in Texas: 21 crashes
  • I-10 in Louisiana: 20 crashes
A chart showing the 25 worst counties in the US for fog-related roadway fatalities

Hill Law Firm

3 / 4

The 25 worst counties

The worst county in the United States for fog-related fatal crashes was Hendry County, Florida. Here, nearly 8 percent of all fatal crashes (22 in total) occurred in foggy conditions.

Rounding out the top five were Lane and Marion Counties in Oregon, Madera County in California, and Fort Bend County in Texas.

Interestingly, five counties in California's Central Valley (Madera, Kings, San Joaquin, Fresno, and Merced) appear in the top 25. This region is notorious for a special kind of dense fog called "tule" (TOO-lee) fog, during winter. This fog can be so thick that it is often visible on satellite. It should come as no surprise, then, that CA SR-99, the road where the most fog-related crashes occurred during the observation period, runs right through the Central Valley.

Which states have the deadliest fog?

Which states have the deadliest fog? Hill Law Firm ranked them by the total number of fatal fog crashes and the percentage of all fatal collisions that involved fog.

#1: Louisiana

289 Fog Crashes

Fog Crash Rank: #6

Share of all Crashes: 1.81 percent

Fog Share Rank: #5

#2: Texas

971 Fog Crashes

Fog Crash Rank: #1

Share of all Crashes: 1.44 percent

Fog Share Rank: #10

#3: Washington

213 Fog Crashes

Fog Crash Rank: #12

Share of all Crashes: 2.02 percent

Fog Share Rank: #3

#4: Oregon

206 Fog Crashes

Fog Crash Rank: #15

Share of all Crashes: 2.48 percent

Fog Share Rank: #2

#5: Pennsylvania

343 Fog Crashes

Fog Crash Rank: #4

Share of all Crashes: 1.33 percent

Fog Share Rank: #14

#6: Missouri

261 Fog Crashes

Fog Crash Rank: #9

Share of all Crashes: 1.41 percent

Fog Share Rank: #12

#7: West Virginia

165 Fog Crashes

Fog Crash Rank: #21

Share of all Crashes: 2.53 percent

Fog Share Rank: #1

#8: Wisconsin

204 Fog Crashes

Fog Crash Rank: #16

Share of all Crashes: 1.65 percent

Fog Share Rank: #7

#9: North Carolina

341 Fog Crashes

Fog Crash Rank: #5

Share of all Crashes: 1.22 percent

Fog Share Rank: #20

#10: Illinois

269 Fog Crashes

Fog Crash Rank: #8

Share of all Crashes: 1.24 percent

Fog Share Rank: #19

#11: Florida

659 Fog Crashes

Fog Crash Rank: #3

Share of all Crashes: 1.14 percent

Fog Share Rank: #24

#12: Indiana

207 Fog Crashes

Fog Crash Rank: #14

Share of all Crashes: 1.29 percent

Fog Share Rank: #16

#13: California

755 Fog Crashes

Fog Crash Rank: #2

Share of all Crashes: 1.08 percent

Fog Share Rank: #28

#14: Alabama

227 Fog Crashes

Fog Crash Rank: #10

Share of all Crashes: 1.22 percent

Fog Share Rank: #21

#15: Minnesota

141 Fog Crashes

Fog Crash Rank: #25

Share of all Crashes: 1.62 percent

Fog Share Rank: #8

#16: Kentucky

199 Fog Crashes

Fog Crash Rank: #18

Share of all Crashes: 1.28 percent

Fog Share Rank: #17

#17: Arkansas

149 Fog Crashes

Fog Crash Rank: #23

Share of all Crashes: 1.33 percent

Fog Share Rank: #15

#18: Georgia

285 Fog Crashes

Fog Crash Rank: #7

Share of all Crashes: 0.99 percent

Fog Share Rank: #32

#19: Maine

55 Fog Crashes

Fog Crash Rank: #34

Share of all Crashes: 1.72 percent

Fog Share Rank: #6

#20: Nebraska

67 Fog Crashes

Fog Crash Rank: #31

Share of all Crashes: 1.52 percent

Fog Share Rank: #9

#21: South Carolina

208 Fog Crashes

Fog Crash Rank: #13

Share of all Crashes: 1.1 percent

Fog Share Rank: #27

#22: Iowa

100 Fog Crashes

Fog Crash Rank: #28

Share of all Crashes: 1.4 percent

Fog Share Rank: #13

#23: North Dakota

43 Fog Crashes

Fog Crash Rank: #38

Share of all Crashes: 1.96 percent

Fog Share Rank: #4

#24: Tennessee

215 Fog Crashes

Fog Crash Rank: #11

Share of all Crashes: 1 percent

Fog Share Rank: #31

#25: Oklahoma

148 Fog Crashes

Fog Crash Rank: #24

Share of all Crashes: 1.12 percent

Fog Share Rank: #25

#26: Michigan

202 Fog Crashes

Fog Crash Rank: #17

Share of all Crashes: 0.99 percent

Fog Share Rank: #33

#27: Idaho

56 Fog Crashes

Fog Crash Rank: #33

Share of all Crashes: 1.26 percent

Fog Share Rank: #18

#28: Kansas

96 Fog Crashes

Fog Crash Rank: #29

Share of all Crashes: 1.21 percent

Fog Share Rank: #22

#29: Vermont

19 Fog Crashes

Fog Crash Rank: #45

Share of all Crashes: 1.43 percent

Fog Share Rank: #11

#30: Virginia

150 Fog Crashes

Fog Crash Rank: #22

Share of all Crashes: 0.91 percent

Fog Share Rank: #38

#31: Ohio

193 Fog Crashes

Fog Crash Rank: #19

Share of all Crashes: 0.85 percent

Fog Share Rank: #41

#32: South Dakota

32 Fog Crashes

Fog Crash Rank: #39

Share of all Crashes: 1.18 percent

Fog Share Rank: #23

#33: Mississippi

132 Fog Crashes

Fog Crash Rank: #26

Share of all Crashes: 0.94 percent

Fog Share Rank: #36

#34: Montana

47 Fog Crashes

Fog Crash Rank: #37

Share of all Crashes: 1.12 percent

Fog Share Rank: #26

#35: New York

181 Fog Crashes

Fog Crash Rank: #20

Share of all Crashes: 0.75 percent

Fog Share Rank: #43

#36: New Jersey

115 Fog Crashes

Fog Crash Rank: #27

Share of all Crashes: 0.92 percent

Fog Share Rank: #37

#37: Connecticut

55 Fog Crashes

Fog Crash Rank: #35

Share of all Crashes: 0.98 percent

Fog Share Rank: #34

#38: Maryland

96 Fog Crashes

Fog Crash Rank: #30

Share of all Crashes: 0.88 percent

Fog Share Rank: #40

#39: Rhode Island

15 Fog Crashes

Fog Crash Rank: #48

Share of all Crashes: 1.08 percent

Fog Share Rank: #29

#40: New Hampshire

23 Fog Crashes

Fog Crash Rank: #43

Share of all Crashes: 0.95 percent

Fog Share Rank: #35

#41: Colorado

59 Fog Crashes

Fog Crash Rank: #32

Share of all Crashes: 0.53 percent

Fog Share Rank: #46

#42: Alaska

15 Fog Crashes

Fog Crash Rank: #49

Share of all Crashes: 1.07 percent

Fog Share Rank: #30

#43: Massachusetts

54 Fog Crashes

Fog Crash Rank: #36

Share of all Crashes: 0.7 percent

Fog Share Rank: #44

#44: Wyoming

24 Fog Crashes

Fog Crash Rank: #42

Share of all Crashes: 0.91 percent

Fog Share Rank: #39

#45: Utah

32 Fog Crashes

Fog Crash Rank: #40

Share of all Crashes: 0.63 percent

Fog Share Rank: #45

#46: Delaware

19 Fog Crashes

Fog Crash Rank: #46

Share of all Crashes: 0.81 percent

Fog Share Rank: #42

#47: New Mexico

29 Fog Crashes

Fog Crash Rank: #41

Share of all Crashes: 0.39 percent

Fog Share Rank: #47

#48: Nevada

20 Fog Crashes

Fog Crash Rank: #44

Share of all Crashes: 0.32 percent

Fog Share Rank: #48

#49: Arizona

17 Fog Crashes

Fog Crash Rank: #47

Share of all Crashes: 0.09 percent

Fog Share Rank: #51

#50: Hawaii

7 Fog Crashes

Fog Crash Rank: #50

Share of all Crashes: 0.31 percent

Fog Share Rank: #49

#51: District of Columbia

2 Fog Crashes

Fog Crash Rank: #51

Share of all Crashes: 0.29 percent

Fog Share Rank: #50 

An image listing safety tips for navigating fog conditions

Hill Law Firm

4 / 4

Safety tips when you encounter fog

If you have ever encountered dense fog while driving, you understand how deeply it can affect your ability to see around your vehicle. While it can be an intense and even harrowing situation, understanding what to do can go a long way toward avoiding a serious car accident.

The best thing you can do when fog sets in is to wait it out. If possible, don't drive until the fog lifts.  However, if you must drive in foggy conditions, some general safety tips are:

  • Turn on fog lights and low-beam headlights.
  • Never use high-beam lights. High beams cause glare and can make it much more difficult for you the road in front of you.
  • Reduce your vehicle speed and allow for extra time to reach your destination.
  • Maintain a safe distance from lead vehicles, increasing your following distance to give you enough time to react.
  • Use roadside reflectors on the right side to keep from entering other lanes and as a guide around curves.
  • If visibility is near zero, pull over into a safe location such as a business or parking lot. If such a location is unavailable, pull your vehicle as far off of the road as possible and turn off all lights except for hazards.

This story was produced by Hill Law Firm and reviewed and distributed by Stacker Media.

Related stories

Trending stories