A California interstate sign with a blue sky background

Gguy44/Getty Images

There are a variety of factors that can make a particular thoroughfare notorious. Just look at the most dangerous roads in the world, which include hazards like excessive sharp corners, narrow designs, dizzying heights, or even the potential for armed conflict. While there are certainly plenty of dicey routes that carve their way through the U.S., California offers some notable examples. Moneygeek, a personal finance technology company, has crunched the numbers surrounding more than 10,300 lethal accidents to identify which roads in California are most dangerous.

These statistics also take into account the number of deadly accidents per mile, which helps narrow down the roads and the specific sections those accidents occur in. By zeroing in on particularly troubling bits of these thoroughfares, the stats provide insight into why these areas are so problematic.

In terms of the top three, the most dangerous stretch of highway in the state was identified as the I-15. Between the outskirts of Hesperia and the Cajon Pass, there were 4.2 deaths per mile over a particular 4.5-mile section. Interestingly, the sections that grabbed second and third are adjacent to one another, covering parts of I-80 through Berkeley and San Pablo. These areas, both measuring five miles, produced 3 deaths per mile through Berkeley and 2.6 through San Pablo. According to Visit California, the state offers “more than 50,000 miles of good-quality highways and freeways.” So, along all that road, what makes these tiny segments so perilous?

Mountainous terrain, congestion, poor infrastructure, and confusing intersections

The I-15 is a major interstate route running north from the city of San Diego through the states of Nevada, Utah, Idaho, and Montana. In California, the I-15 is a popular route that connects Los Angeles to Las Vegas. The average number of daily vehicles reached over 50,000 in the last few years, but the most treacherous bit is just around an hour or two outside of central Los Angeles. This section of the I-15 winds over a mountain pass. Given the amount of traffic, including a significant presence of commercial trucks, the curves, steep grades, fierce wind, fog, and snow also contribute to accidents. Concerning the I-15 near Cajon Pass, there is even a website, PainInThePass, dedicated to reporting on incidents along this route.

For the I-80 through Berkely (just North of Oakland in northern California), one of the biggest pain points, the Gilman interchange, is described by BerkleySide readers as “the most dysfunctional intersection” in the entire U.S. Among the problems at I-80 and Gilman Street are several points of entry, right of way confusion, and challenging merging requirements. Multiple roundabouts are present that should be able to help alleviate things, although considering we’ve previously covered how Connecticut drivers have no idea how to use roundabouts, it’s unclear how well Californians are using them.

Finally, just north of Berkely, another segment of I-80 is also problematic through San Pablo. The issue is severe congestion around the San Pablo Dam Road, which is the subject of an anti-congestion project planned nearly a decade ago and estimated to cost in the hundreds of millions. The immense levels of traffic, as well as the lack of adequate pedestrian and cyclist pathways, all contribute to this area’s infamy.