Key Takeaways:
- Newport Boulevard and 22nd Street/Victoria Street in Costa Mesa is the most dangerous intersection in California.
- Edinger Avenue and Ward Street in Fountain Valley has experienced the most fatal injuries out of all intersections in California.
- Among the 50 most dangerous intersections, six of them are found in San Jose, more than in any other city in California.
- Intersection crashes increased by 40% from 2020 to 2023. (as 2024 does not include a full year of data, we have excluded it from year over year analysis)
- Failing to obey traffic signals and signs was the leading cause of crashes at the intersections in our top 50 ranking.
- Crashes involving alcohol are more than twice as likely to result in severe or fatal injuries compared to minor injuries.
As the most populous state in the country, California is home to millions of residents and major cities that attract tourists from around the world, as well as a constant flow of out-of-state visitors. With its busy roads and high traffic volume, the state experiences a significant number of car collisions, particularly at intersections.
In this study, we analyzed data from the Statewide Integrated Traffic Records System (SWITRS), which was cleaned and geocoded by the Transportation Injury Mapping System (TIMS) from 2020 to August of 2024 to identify the 50 most dangerous intersections in California. We examined how crash numbers have evolved over the years, the severity of these crashes, the most common primary causes, the most frequent collision types, and the lighting conditions that most intersection crashes fall under.
It’s important to note that our dataset only includes crashes where an injury, of any severity, was reported or suspected. Collisions classified as less severe are not reported in the dataset and are therefore not included in our analysis. Our findings are specifically based on crashes that occurred at the top 50 most dangerous intersections.
Ranking Intersection Danger Scores
The intersections listed below are ranked based on a composite metric we call the “danger score.” This score takes into account the total crash volume in a five year period as well as the same crashes categorized by severity, with each severity level weighted accordingly.
Costa Mesa, a city in Orange County, is home to California’s most dangerous intersection: Newport Boulevard and 22nd Street/Victoria Street. This intersection saw a total of 33 crashes in five years, with seven resulting in severe injuries and 21 in minor injuries, earning a danger score of 96. While this intersection does not have the highest number of total crashes, it has the most crashes involving minor and severe injuries among the top 50, and is one of four with the most serious injury crashes overall. Newport Boulevard, also designated as SR-55, functions as a surface street before transitioning into a freeway just north of the intersection. After passing through the traffic light, drivers must either merge onto SR-55 North or avoid it entirely, creating a high-risk situation. The combination of congested traffic, sudden speed changes, and the decision to either enter or bypass the freeway significantly increases the likelihood of collisions.
In second place is the intersection of Route 232 (Vineyard Avenue) and Esplanade Drive in Oxnard, with a total of 64 crashes, including 12 resulting in minor injuries, giving it a danger score of 88. It has the highest total crash count among all intersections, though none were fatal. However, 81% of crashes involved a suspected injury, and it has the highest total number of injuries (144)—all classified as minor or suspected. Its proximity to the northbound Highway 101 exit and entrance ramps likely contributes to congestion as vehicles transition between surface streets and the freeway.
Third on the list is Lakewood Boulevard and Firestone Boulevard, with a danger score of 86. This intersection saw 56 total crashes, two of which resulted in severe injuries and 12 in minor injuries. Lakewood Boulevard is a heavily trafficked, wide road running north-south, connecting several cities in the Los Angeles area. Firestone Boulevard runs east-west, providing access to residential and commercial areas. The intersection is surrounded by various businesses, including shopping centers, fast food restaurants, and retail establishments, which can contribute to heavy traffic.
Notably, the intersection of Edinger Avenue and Ward Street, ranked 9th on the list, stands out due to the highest number of fatalities among the top 50, all involving pedestrian crossings. It drew attention following a hit-and-run incident on March 18, 2021, when a driver ran a red light, struck a pedestrian, and fled the scene. The driver was later identified and convicted of the crime in 2023, bringing closure to the case.
The intersection of Avenue M and 30th Street, ranked 31st on the list, has the highest share of crashes resulting in serious injury, with approximately one in four crashes leading to severe harm.
Below, we have visualized the proportions of different injury severities: fatalities, serious injuries, minor injuries, and possible injuries across each of the top 50 intersections.
Here, we present the number of crashes by city that contain the most dangerous intersections from our ranking.
For more information on intersection crashes in key California cities, please view the pages below:
What’s Causing the Most Crashes?
Understanding the primary causes of intersection crashes helps highlight the most common driver and pedestrian behaviors that lead to collisions. Below, we break down the top violations contributing to crashes at California’s most dangerous intersections.
Among the top 50 most dangerous intersections in California, failing to obey traffic signals and signs, which includes drivers running red lights or ignoring stop signs, was the leading cause of crashes, accounting for 591 incidents. The second most common cause was violating the automobile right of way, responsible for 437 crashes. This category includes failures to yield when required, which often lead to side-impact or T-bone collisions. Unsafe speed ranked third, contributing to 156 crashes, as excessive speed makes it harder for drivers to react in time at busy intersections.
Other significant contributors include improper turning (138 crashes), where drivers made unsafe left or right turns, and driving under the influence of alcohol or drugs (69 crashes), which remains a persistent risk despite strict laws.
While 69 crashes were attributed to driving under the influence of alcohol or drugs as the primary cause, a total of 137 crashes involved alcohol to some capacity without necessarily being the primary fault. Below, we analyze intersection crashes involving alcohol by crash severity.
The chart highlights the significant impact of alcohol impairment. Among crashes resulting in fatal or severe injuries, 16.03% were alcohol-related, compared to only 7.46% of crashes involving minor injuries. This difference emphasizes how impaired driving significantly increases the likelihood of severe outcomes. Alcohol impairs coordination, slows reaction times, and heightens the potential for high-impact collisions.
We’ve also analyzed all the primary causes reported for intersection crashes at the most dangerous intersections by crash severity.
Traffic signals and right-of-way violations are the most commonly cited causes of severe crashes. Among all fatal or severe injury crashes, 33.97% were attributed to failing to obey traffic signals and signs, while 23.72% were caused by automobile right-of-way violations. These two categories also accounted for the highest share of less severe crashes, 35.82% and 26.63%, respectively.
Some violations are disproportionately cited in severe crashes. Driving under the influence of alcohol or drugs was listed as the primary cause in 9.62% of fatal or severe injury crashes. This is nearly three times its share in minor crashes (3.60%). Pedestrian violations showed an even more striking disparity, making up just 0.67% of crashes of minor severity but 10.26% of fatal or severe crashes.
Speeding and improper turning also play a role. Unsafe speed was cited as the primary cause in 8.97% of severe crashes and 9.45% of all other crashes. This suggests that while speeding contributes to intersection crashes, its impact on severity is more balanced. Improper turning was responsible for 5.13% of fatal or severe injury crashes and 8.66% of all other crashes, indicating that turning errors more frequently lead to minor incidents.
Below we’ve compared the primary causes by intersection rank to determine what sets the most dangerous intersections apart from all others.
Traffic signal violations are significantly more common at high-risk intersections. Among crashes occurring at the 50 most dangerous intersections, 35.65% were caused by drivers failing to obey traffic signals and signs, compared to 27.3% at all other intersections. This suggests that intersections with a high volume of crashes may have factors that contribute to frequent red-light running or sign violations, such as heavy congestion, unclear signage, or poor visibility.
Right-of-way violations are cited less frequently at high-risk intersections. While automobile right-of-way violations remain a leading cause of crashes, they were slightly less common at the most dangerous intersections (26.36%) than at all other intersections (30.2%).
Speeding plays a similar role across all intersections. Unsafe speed was cited as the cause in 9.41% of crashes at the top 50 intersections and 10.35% at other intersections. This makes sense as speeding is dangerous in any road layout and situation.
Alcohol-related crashes are more common outside the most dangerous intersections. Driving under the influence of alcohol or drugs was the cause of 4.16% of crashes at the 50 most dangerous intersections, compared to 5.31% at all other intersections. A similar outcome was observed for pedestrian violations. Only 1.39% of crashes at the top 50 intersections were attributed to pedestrian right-of-way violations, compared to 4.39% at all other intersections.
The Most Common Types of Intersection Collisions
We have identified the leading causes of intersection crashes. Now, let’s examine how these collisions actually occur. Below, we break down the most common types of crashes.
T-bone collisions, also known as broadside collisions, are by far the most common type of intersection crash, accounting for 1,020 incidents. This is expected, as intersections inherently involve crossing traffic, creating opportunities for these side-impact crashes when drivers run red lights, fail to yield, or misjudge oncoming traffic.
Head-on collisions, while less frequent, still represent a significant portion of crashes, with 224 recorded incidents. These crashes often result from drivers making improper turns, traveling on the wrong side of the road, or miscalculating the speed of oncoming vehicles. Rear-end collisions (161 crashes) are another common occurrence, typically caused by drivers following too closely or failing to anticipate sudden stops at signals.
Below we’ve analyzed collision type by crash severity and intersection rank.
While T-bone collisions (broadside crashes) are the most common type of intersection crash overall, they are slightly less dominant in severe crashes (53.85%) compared to all other severities (62.32%). This suggests that while broadside collisions frequently occur, not all of them result in serious injuries or fatalities. However, they still account for the majority of severe crashes.
Head-on collisions make up 14.74% of fatal and severe injury crashes, a slightly higher proportion than their 13.38% share of less severe crashes. The direct impact of these crashes increases the likelihood of severe injuries, even though they are less frequent than T-bone crashes overall.
Pedestrian collisions show the most dramatic difference. While they make up only 3.06% of all other crashes, they account for 17.95% of fatal or severe injury crashes. These figures mirror the extreme vulnerability of pedestrians in traffic, as even low-speed impacts can result in critical injuries.
Rear-end collisions are typically less severe, with rear-end crashes making up 10.12% of minor crashes and none in the severe category. Side-swipes, often low-impact, are more common in minor crashes (6.52%) and rarely serious (1.28%). Rollover crashes are rare in all cases.
Some patterns observed in this table are largely consistent with the previous analysis across crash severity. T-bone collisions remain the most common type of crash at both high-risk and other intersections, making up a significant proportion of intersection crashes (61.52% and 58.63%, respectively), aligning with their prominence in both fatal/severe and minor injury categories.
Head-on collisions are more frequent at the top 50 intersections (13.51%), reflecting a higher likelihood of more severe outcomes at these high-risk sites, as seen in the previous section. Meanwhile, rear-end, side-swipe, and rollover collisions are more evenly distributed across both sets of intersections, with no major difference in their proportions. Pedestrian collisions are more common at intersections outside of the top most dangerous.
Night vs. Day: When Do Intersection Crashes Happen Most?
Now, let’s analyze the impact of lighting conditions on intersection crashes, examining how visibility during different times of day correlates with crash frequency and severity, as well as how lighting affects the most dangerous intersections in the state.
The table above shows the distribution of intersection crashes across various lighting conditions at the top 50 most dangerous intersections. Daylight accounts for the highest number of crashes, with 1,004 incidents recorded. Dark conditions with street lights follow, with 564 crashes. Crashes during dusk, dawn, and in areas without street lighting are less common.
Below, we have analyzed the lighting conditions of intersection crashes by crash severity and intersection rank.
Notably, daylight and dark conditions with street lights are associated with a substantial proportion of both severe collisions and collisions of minor severity, though daylight crashes have a slightly higher proportion of minor incidents (62.12%) compared to fatal or severe injuries (45.51%). In contrast, dark intersections with street lights are more likely to result in fatal or severe injuries, with 47.44% of crashes in this lighting condition falling into this category. This suggests that even well-lit areas can be hazardous.
When it comes to more challenging conditions like dusk/dawn and dark intersections without street lights, fatal and severe injuries are less common. However, dusk and dawn crashes still present a risk of 4.49% for severe outcomes.
Unsurprisingly, most crashes occur in daylight at both high-risk and other intersections, but it is slightly more frequent at non-top 50 intersections (67.26%) than at the top 50 intersections (60.55%).
Dark intersections with street lights are the second most common lighting condition for crashes, particularly at top 50 intersections (34.02%). This contrasts with all other intersections, where the proportion of crashes in dark intersections with street lights is lower (25.66%). These roads are well-lit due to high traffic volumes, yet they remain dangerous due to additional risk factors.
For dusk-to-dawn conditions, the proportions are relatively similar between top 50 intersections (3.74%) and all other intersections (3.92%), indicating that this lighting condition affects intersections broadly, though it’s less common overall. The remaining lighting conditions reported exhibit low yet comparable figures between both intersection categories.
The Road Ahead: Making Intersections Safer in California
Intersections are among the most complex and high-risk areas on California’s roads, and our analysis of crash data from 2020 to 2024 highlights just how dangerous they can be. The state’s most hazardous intersections see a high volume of crashes, often due to common but preventable violations like running red lights, failing to yield, and speeding.
While intersection crashes increased steadily between 2020 and 2023, the trend appears to be reversing itself in 2024 in the state overall. However, not all cities experienced improvements, reflecting that intersection safety remains an ongoing challenge.
Our findings also reveal important patterns: T-bone collisions are the most frequent crash type, and traffic signal violations play an outsized role at the most dangerous intersections. Alarmingly, alcohol-related crashes, while less common overall, are disproportionately severe, with impaired driving significantly increasing the likelihood of fatal or serious injuries.
Addressing these dangers requires a multi-faceted approach, including improved traffic enforcement, better signal timing, clearer signage, and infrastructure upgrades that prioritize safety. As California continues to grow, understanding and mitigating intersection risks will be crucial in reducing crashes and protecting all road users.
Methodology
This study analyzed crash SWITRS data, cleaned and geocoded by TIMS, from 2020 through August 31st of 2024 to identify the 50 most dangerous intersections in California. We focused on collisions involving injuries, examining factors like crash frequency, severity, primary causes, collision types, and lighting conditions. The data was normalized to rank the intersections based on their overall danger index, considering both the frequency and severity of crashes.
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