[Study] The Deadliest Highway Stretches in California

This map is interactive. You can zoom in and hover over any orange road segment to get information such as highway name, number of fatalities, fatalities per mile and road segment length.

In 2015 and 2016, there were over 6,500 fatal motor vehicle collisions in California – the second highest state total in the country as only Texas had more.  Nearly 39 percent of these fatal collisions occurred on an Interstate, U.S. or State Highway.

The California State Highway System is a sprawling, 16,662-mile-long network consisting of over 50,000 lane miles.  Where along this vast network do fatal collisions occur at a high rate?  Are certain sections of highway inherently dangerous for drivers?

With the help of data visualization firm 1Point21 Interactive, we analyzed all fatal highway collisions in 2015 and 2016 (the most current year available) to identify the deadliest stretches in California.

Study Insights

• The top 15 stretches accounted for 160 fatal crashes and 172 fatalities.
• These stretches averaged 1.48 fatal collisions per mile, compared to 0.15 for the entire highway network.
• 10 of the 15 deadliest stretches are located in Southern California, while only 5 are located in Northern California.

The 15 Deadliest Stretches of Highway in California

You can quickly jump to the following sections of the study:

• Deadliest Highway Stretches in Southern California
• Deadliest Highway Stretches in Northern California

*The rank of the stretches is determined by fatal crashes per mile.

The four deadliest highway segments – based on fatal crashes per mile –  are primarily comprised of smaller, local highways rather than the traffic-packed interstates that see hundreds of thousands of vehicles every day.

• The deadliest highway stretch was a 3.51-mile segment of Sierra Highway in Canyon Country in the Santa Clarita Valley that accounted for 10 crashes and 11 fatalities.
• Ranking second was a 3.70-mile stretch of State Route 74 in Hemet, CA (also known as Florida Avenue) that runs through the central hub of the small city. This busy street was the location of 8 crashes and 10 fatalities.
• The third-most deadly segment was a 3.32-mile stretch of State Route 57 that runs through Anaheim’s Resort District and ends in bustling Santa Ana.
• Fourth place went to a wide, 9.82-mile-long segment of Beach Boulevard, a heavily-traveled north-south arterial road that begins in Buena Park and runs through Westminster, ending just north of Huntington Beach.

Deadliest Stretches in Southern California

The majority of deadly highway stretches were located in Southern California – 50 percent of the segments in the region were the site of at least 10 fatalities. When broken down by county, Los Angeles County has far and away the most dangerous segments, with 16 targeted highways, followed by Riverside County with 8 stretches.

Aside from the aforementioned top 4 ranking segments, a surprising addition is a 6-mile stretch of Union Avenue, a highway corridor in Bakersfield. With 9 crashes leading to 9 fatalities, it ranked fifth in Southern California, and sixth overall.

Other Notable Segments

• A 5.76-mile segment of Interstate 405, largely considered the busiest freeway in the nation, was home to 6 crashes and 7 fatalities.
• A long stretch of Interstate 5 running through LA was second in the region in crashes and fatalities, with 28 each. However, due to its length of roughly 28 miles, its fatal crash density did not rank as high as other, smaller highway segments.
• A small, 6.33-mile stretch of Historic Route 66 in the Angeles National Forest south of Hesperia accounted for 6 crashes and 6 fatalities, ranking 8th in Southern California and 12th
• A large stretch of Interstate 10 running through San Bernadino and beyond accumulated 36 crashes and 39 fatalities – the most on the list overall. However, because these occurred across a stretch of 44.35 miles, it ranked lower than shorter segments due to a lower fatal crash density.

Interestingly, San Diego County was not as high on the list as others, despite ranking second in population only to Los Angeles County. Their deadliest highway segment ranked 19th, a 10.07-mile stretch of Interstate 8 through the busy Mission Valley neighborhood – accounting for 8 crashes and 9 fatalities.

UPDATE: Check out our New Infographic! – Where are the Top 5 Deadliest Freeway Areas in Los Angeles?

Deadliest Stretches in Northern California

With only 18 stretches, Northern California had considerably less visibility than its southern counterparts. While Southern California has three segments with a fatal crash density above 2, Northern California has zero. Its deadliest highway segment was a portion of Interstate 880 through Milpitas with a fatal crash density of 1.87. Despite being only 3.21 miles long, this stretch was the location of 6 crashes, leading to 6 fatalities.

Other Notable Segments

• A 4.68-mile segment of State Route 183 leading from Salinas to Castroville that was the site of 7 crashes and 9 fatalities.
• A 37.24-mile stretch of US Highway 101 running through San Jose and ending in San Mateo that accounted for 26 crashes and 28 fatalities – the longest stretch in Northern California with the highest amount of crashes and fatalities.
• A segment south of Sacramento accounted for 15 crashes and 17 fatalities across a 14.11-mile stretch of State Highway 99 – ranking 4th in Northern California.
• A stretch of State Highway 99 through Modesto contained 18 crashes and 18 fatalities across 22.46 miles, ranking 8th in fatal crash density in Northern California.

San Francisco, one of the most densely populated cities and counties in the region, actually had zero deadly highway segments. The closest was a stretch of Interstate 580 across the bay that accounted for 12 crashes and 13 fatalities.