Any Fresno truck accident attorney who handles serious Highway 99 crashes knows that jackknife accidents are among the most violent and legally complex collisions in the Central Valley. When a tractor-trailer jackknifes, the trailer swings outward at an angle, often blocking multiple lanes of traffic in seconds. On a high-speed freight corridor like Highway 99, that loss of control rarely involves just one vehicle.
For drivers in Fresno County, jackknife crashes are especially dangerous because they tend to happen where traffic is dense, speeds are high, and escape routes are limited. Understanding why these crashes occur, what injuries they cause, and how fault is determined can make a critical difference after a serious accident.
What Happens During a Jackknife Accident
A jackknife accident occurs when the cab and trailer of a semi-truck fold toward each other, forming a sharp angle similar to a pocketknife. This usually happens when the trailer loses traction while the cab continues moving forward.
On Highway 99, jackknife crashes often unfold in seconds. A sudden brake, a lane change, wet pavement, or uneven cargo can cause the trailer to slide sideways. Once that motion begins, it is extremely difficult for the driver to regain control, especially at freeway speeds.
Because Highway 99 runs directly through Fresno and connects major agricultural and distribution hubs, these crashes often involve multiple passenger vehicles caught in the trailer’s path.
Why Jackknife Accidents Are Common on Highway 99
Several conditions make Highway 99 particularly vulnerable to jackknife crashes.
Heavy Freight Volume
Highway 99 carries a constant stream of semi-trucks hauling produce, refrigerated goods, and commercial freight. The sheer volume of trucks increases the risk of braking events, congestion, and sudden slowdowns that can trigger a jackknife.
Sudden Traffic Changes
Traffic on Highway 99 can shift quickly, especially near on-ramps, construction zones, and urban exits through Fresno. When traffic slows abruptly, truck drivers may brake hard to avoid a collision ahead, increasing the risk of trailer swing.
Road Surface Conditions
Oil residue, rain, Tule fog moisture, and uneven pavement reduce traction. When a trailer loses grip even briefly, it can slide out of alignment with the cab.
Improperly Loaded Cargo
Uneven or overweight loads are a major contributor to jackknife accidents. When cargo shifts inside a trailer, it alters the truck’s center of gravity, making the trailer more likely to swing during braking or turning.
A Fresno truck accident attorney investigating a jackknife crash will almost always examine load records and weight distribution, not just driver behavior.
Common Injuries in Jackknife Crashes
Jackknife accidents rarely cause minor injuries. The force involved, combined with the size of the trailer, leads to severe outcomes.
Victims often suffer traumatic brain injuries, spinal cord damage, crushed limbs, internal organ injuries, multiple fractures, and fatal blunt-force trauma. Because trailers frequently block several lanes, secondary impacts are common, turning one jackknife into a chain-reaction crash.
In Fresno County, these collisions often involve commuters, farm workers, and families traveling between cities along Highway 99, amplifying the human cost.
Who Is at Fault in a Jackknife Accident
Fault in a jackknife accident is rarely straightforward. While trucking companies often attempt to blame road conditions or other drivers, liability usually extends further.
The Truck Driver
Driver error plays a role when a trucker speeds for conditions, brakes aggressively, follows traffic too closely, or fails to adjust driving during fog or rain. Fatigue is also a common factor, especially on long Central Valley routes.
The Trucking Company
Many jackknife accidents trace back to company practices rather than individual mistakes. Pressuring drivers to meet deadlines, allowing overloaded trailers, skipping maintenance, or failing to train drivers properly can all place responsibility on the trucking company.
Cargo Loaders or Third Parties
If cargo was improperly loaded by a separate company, liability may fall on the shipper or loading crew. Unbalanced or unsecured freight dramatically increases jackknife risk.
Maintenance Providers
Brake failures, worn tires, or defective anti-lock braking systems can contribute to loss of control. Maintenance records often reveal whether a truck should have been on the road at all.
A skilled Fresno truck accident attorney looks beyond the crash itself and reconstructs everything that happened in the hours and days leading up to it.
Why Jackknife Cases Require Immediate Investigation
Jackknife accidents generate critical evidence that can disappear quickly. Tire marks fade, electronic data is overwritten, and damaged vehicles are repaired or scrapped. Trucking companies often deploy investigators immediately to control the narrative.
Early legal action helps preserve black box data, braking records, driver logs, dispatch communications, load documentation, and maintenance history. Without that evidence, proving fault becomes significantly harder.
This is why victims are often advised not to give statements to insurance companies until they understand the full scope of what caused the crash.
What to Do After a Jackknife Accident on Highway 99
If you are involved in or injured by a jackknife accident, medical care comes first. Beyond that, documenting the scene, obtaining witness information, and seeking legal guidance early can protect your rights.
Highway 99 jackknife crashes are not routine accidents. They involve federal trucking regulations, complex liability issues, and high-stakes insurance claims. Having the right legal team matters.
If you or someone close to you was injured in a jackknife accident on Highway 99, you can contact Bojat Law Group at (818) 877-4878 for a free consultation. Our team handles serious truck accident cases throughout Fresno County and works to uncover every factor that contributed to the crash, not just the version presented by the trucking company.