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HERCULES, Contra Costa County, Calif., Oct. 1, 2026 — Children were reportedly hurt Wednesday morning, September 30, when a semi-truck, a sedan and an SUV collided on westbound State Route 4 at the Willow Avenue off-ramp, according to the California Highway Patrol.
The crash was reported shortly before 9:30 a.m. near the Willow Avenue undercrossing, the CHP said. Initial radio traffic described a red diesel tractor-trailer involved in a collision with a white Toyota Corolla and a dark-colored SUV, blocking the slow lane of the freeway.
Early reports to dispatchers indicated a child was struck in the head during the crash, and the CHP said juveniles inside one of the vehicles were hurt. Paramedics were requested to treat injuries at the scene, and the collision was initially classified as a minor-injury crash.
A tow truck was called to remove the Toyota, which reportedly sustained major damage to its rear end. A fire crew responding to the scene told dispatchers the number two lane remained blocked, and all involved vehicles were eventually moved to the right shoulder as crews worked to clear the roadway.
The California Highway Patrol has not released the ages or conditions of those injured, and the cause of the crash remains under investigation.
We hope everyone who was hurt makes a full recovery.
When Truck Crashes on Freeway Off-Ramps Tend to Happen
Morning commute hours bring a mix of slowing traffic, merging vehicles and drivers unfamiliar with sudden lane drops near off-ramps, conditions that can catch large trucks off guard. Around 9 to 10 a.m., traffic volume is still heavy from the morning rush, and trucks that were moving at highway speed may need to brake quickly as cars ahead slow for an exit.
Visibility is generally good during these hours, but the added traffic density changes the margin for reaction time. A loaded semi-truck needs far more distance to slow down than a passenger car, so a slowdown that a sedan driver can manage easily may not leave a truck driver enough room to stop.
According to the National Highway Traffic Safety Administration, 4 percent of large-truck drivers involved in fatal crashes had blood alcohol concentrations of .08 g/dL or higher in 2023. Weekday daytime crashes like this one are generally not linked to impairment, pointing instead to following distance, speed differences and the physical limits of stopping a heavy vehicle in traffic.
Frequently Asked Questions
Why do trucks need so much distance to stop?
A fully loaded semi-truck can weigh twenty times as much as a passenger car. That extra weight means far more momentum, so even with good brakes, a truck traveling at highway speed needs several hundred feet more to come to a stop than a car does.
What makes truck crashes different from typical car accidents?
The size and weight gap between a truck and a passenger vehicle means the smaller vehicle absorbs most of the force in a collision. Occupants of cars and SUVs involved in crashes with trucks are more likely to be seriously hurt than the truck's own occupants.
What are truck blind spots and why do they matter?
Large trucks have wide blind spots along both sides, directly behind the trailer, and close to the front of the cab. Drivers in cars should avoid lingering in these zones, since a truck driver may not see them before changing lanes or slowing down.
What is an underride crash?
An underride crash happens when a smaller vehicle slides partly or fully beneath a truck's trailer during a collision, often because the vehicle's body sits lower than the trailer bed. These crashes can cause severe damage to the smaller vehicle's upper frame and occupant space.
What to Do After a Truck Crash in Hercules, CA
If you're involved in a crash with a semi-truck, try to move to a safe area away from traffic and call 911 right away, even if injuries seem minor at first. Children and adults alike should be checked by a medical professional after any truck collision, since impacts can cause injuries that aren't immediately obvious, including to the head or neck.
Take photos of the scene if it's safe to do so, and get the names and contact information of anyone else involved or who witnessed the crash. Request a copy of the official collision report once it's available, and keep records of any medical visits connected to the crash for your own files.
