America is a country of roads. Every state has its own highway system, while nationally there is the interstate and numbered highway system. All in all, there are 2.7 million miles of road in the U.S. — enough to go around the Earth 107.2 times! Not every road has a great safety record though. Some are simply more dangerous than others. In this study we explored the 50 most dangerous roads in America. We go into how often a fatal accident occurs, and what makes these roads dangerous.

Top Five Most Dangerous Roads in the U.S.

1. State Route 99 (California)

62.3 Fatal Accidents per 100 Miles

Deadliest City: Fresno (34 fatal accidents)

2. I-45 (Texas)

56.5 Fatal Accidents per 100 Miles

Deadliest City: Houston (51 fatal accidents)

3. I-95 (Florida to Maine)

55.1 Fatal Accidents per 100 Miles

Deadliest City: Jacksonville (63 fatal accidents)

4. I-10 (California to Florida)

54.5 Fatal Accidents per 100 Miles

Deadliest City: New Orleans (89 fatal accidents)

5. I-75 (Florida to Michigan)

47.2 Fatal Accidents per 100 Miles

Deadliest City: Detroit (38 fatal accidents)

California Route 99, despite being a relatively shorter highway, had the most fatal accidents per 100 miles of any highway in the nation. The state route which cuts up the center of California had a total of 264 fatal accidents between the years 2011 and 2015. In second place, I-45 in Texas was another short highway, that also had a relative high amount of fatalities. The most major of the five is I-10, a trans-continental that runs from Florida to California. Based on total number of fatal accidents, I-10 has the most at 1,342 in the five years we looked at.

How Highways Rank for Different Types of Dangers

What makes these highways dangerous? We looked at three factors that contribute often to crashes: weather, lighting and drunk driving, and evaluated which highways were the most dangerous by category. The tables below have the five worst in each category, ranked based on the number of fatal accidents per 100 miles.

Rainiest and Snowiest Highways

Looking at FARS data from 2011 to 2015, we figured out which highways had the most fatal accidents that occurred in either rain or snow. I-85, which runs from the south up through Virginia, had the highest frequency of fatal accidents in inclement weather. 6.1 fatal accidents occurred under wet conditions per 100 miles in the years we looked at.

Rank	Highway	Fatal Accidents per 100 Miles	Fatal Accidents in Rain or Snow
1	I-85 (AL to VA)	6.1	41
2	I-95 (FL to ME)	5.7	109
3	I-75 (FL to MI)	5.3	94
4	I-20 (TX to SC)	4.7	73
5	I-77 (SC to OH)	4.4	27

Darkest Highways

Next, we looked at the number of fatal accidents that happened in dark areas, without lighting available. These highways were mostly found in the south and the west, the darkest being the SR-99 in California. On the 500 mile highway, every 100 miles had about 26 accidents that happened in the dark. In fact, nearly 40% of all fatal accidents on SR-99 in the last five years have occurred in the dark.

Rank	Highway	Fatal Accidents per 100 Miles	Total Fatal Accidents in Dark
1	SR-99 (CA)	25.5	108
2	I-10 (CA to FL)	19.2	472
3	I-45 (TX)	18.9	54
4	I-85 (AL to VA)	17.3	116
5	I-20 (TX to SC)	16.2	249

Highways with Most Drunk Drivers

Finally, we looked at which highways had the highest frequency of an accident involving a drunk driver. Solidifying its spot as one of America's most dangerous highway was I-45 where we found nearly 18 fatal drunk driving accidents for every 100 miles between the years of 2011 and 2015.

Rank	Highway	Fatal Accidents per 100 Miles	Total Fatal Accidents with Drunk Driver
1	I-45 (TX)	17.5	50
2	SR-99 (CA)	16.9	72
3	I-95 (FL to ME)	13.8	266
4	I-10 (CA to FL)	12.6	310
5	US-17 (FL to VA)	10.9	130

The 50 Most Dangerous Highways in America

Rank	Highway	Length of Road (mi)	Total Fatal Accidents	Deaths per 100 Miles
1	SR-99 California	424	264	62.3
2	I-45	285	161	56.5
3	I-95	1,926	1,061	55.1
4	I-10	2,460	1,342	54.5
5	I-75	1,786	844	47.2
6	I-85	669	315	47.1
7	I-5	1,381	607	43.9
8	I-20	1,539	662	43.0
9	US-17	1,189	461	38.8
10	I-35	1,568	583	37.2
11	I-84 East	232	85	36.6
12	I-65	887	324	36.5
13	US-1	2,377	782	32.9
14	I-15	1,434	470	32.8
15	I-40	2,555	801	31.3
16	SR-1 California	655	189	28.9
17	I-77	610	173	28.4
18	US-101	1,519	408	26.9
19	I-70	2,153	562	26.1
20	I-55	964	249	25.8
21	I-25	1,063	271	25.5
22	I-64	954	238	25.0
23	US-27	1,364	316	23.2
24	US-19	1,386	320	23.1
25	US-301	1,111	255	23.0
26	I-44	634	143	22.6
27	I-80	2,900	653	22.5
28	US-41	2,006	436	21.7
29	US-90	1,633	342	20.9
30	I-94	1,585	319	20.1
31	US-98	939	188	20.0
32	US-60	2,670	443	16.6
33	I-84 West	769	122	15.9
34	US-59	1,911	292	15.3
35	US-29	1,036	150	14.5
36	US-50	3,011	419	13.9
37	US-61	1,400	175	12.5
38	US-441	936	116	12.4
39	US-2	2,112	234	11.1
40	US-69	1,136	124	10.9
41	US-40	2,298	246	10.7
42	US-52	2,072	219	10.6
43	US-70	2,385	235	9.9
44	I-90	3,021	295	9.8
45	US-62	2,248	219	9.7
46	US-6	3,207	266	8.3
47	US-30	3,073	253	8.2
48	US-20	3,237	266	8.2
49	US-64	2,326	187	8.0
50	US-12	2,483	176	7.1

Methodology

To find how dangerous each highway was, we looked at the FARS (Fatality Analysis Reporting System) of the National Traffic and Highway Safety Administration. We took their "Accident" data from 2011 until 2015 and used it to count the number of accidents that occurred on every highway in the U.S. between those years. We then took the number of occurrences and the length of the 50 highways with the most fatal accidents to determine how how often a fatality occurred. We used the same data set to determine the number of fatal accidents that happened in rain or snow, darkness and with a drunk driver. Since these highways go over several states, it was difficult to find the average ridership for each highway, so we use the length of the highway as a surrogate.

Bailey is a Research Analyst at ValuePenguin, covering insurance. He graduated from Occidental College with a B.A. in Mathematics and a minor in Computer Science. Bailey's analysis has been featured by CNBC, the Houston Chronicle and the National Transportation Bureau Safety Board.

Editorial Note: The content of this article is based on the author’s opinions and recommendations alone. It has not been previewed, commissioned or otherwise endorsed by any of our network partners.

The 50 Most Dangerous Roads in America