Miami Tractor-Trailer Jackknife Accident Lawyer

A tractor-trailer jackknife can turn one truck into a barrier stretching across several lanes of traffic.

Jackknifing occurs when the tractor and trailer no longer remain aligned. The trailer swings toward the tractor around the coupling point, creating the folded shape that gives the accident its name. Vehicles beside the truck can be swept into the trailer, crushed between the truck and a barrier, or forced into secondary collisions.

Jackknife accidents are not always unavoidable reactions to an emergency. They can result from excessive speed, poor maintenance, improperly loaded cargo, dangerous road conditions, or a truck driver’s improper choice of braking technique.

Stopping a tractor-trailer safely requires considerably more judgment than simply stepping on a brake pedal. A commercial driver needs to understand the truck’s braking systems, the road surface, the load, and how the tractor and trailer will respond. Choosing the wrong braking method or applying the brakes improperly can cause wheels to lock, traction to disappear, and the trailer to swing out of control.

At Sotolongo Law, our Miami tractor-trailer jackknife accident lawyer investigates what happened before a jackknife began, including how the driver attempted to slow the truck and whether proper driving techniques could have prevented the crash.

How a Tractor-Trailer Jackknifes

A tractor-trailer depends on traction to keep both parts of the combination vehicle traveling in the intended direction.

When wheels lock and begin sliding rather than rolling, they lose much of their ability to provide directional control. If the tractor and trailer experience different levels of traction or deceleration, the trailer can begin rotating around the fifth-wheel connection.

Two related scenarios can occur.

When the trailer wheels lock, the trailer may slide sideways and swing toward the tractor. When the tractor’s drive wheels lose traction, the tractor itself can move sideways relative to the trailer.

Either situation can rapidly become uncontrollable.

The danger is particularly severe on Miami’s multilane highways. A tractor-trailer that begins jackknifing on I-95, the Palmetto Expressway, Dolphin Expressway, I-75, or Florida’s Turnpike can sweep across neighboring lanes with little warning to surrounding motorists.

Different Ways a Truck Driver Can Slow a Tractor-Trailer

Commercial drivers have several methods available to reduce speed. Knowing which method is appropriate and how to use it is an important part of operating a tractor-trailer safely.

Controlled Braking

The Federal Motor Carrier Safety Administration’s Commercial Driver’s License Manual describes controlled braking as applying the brakes as hard as possible without locking the wheels, while keeping steering movements small. If greater steering input becomes necessary or the wheels lock, the driver may need to release the brakes and reapply them as soon as possible.

The objective is maximum braking while preserving traction and control.

That distinction matters enormously in a combination vehicle. Locking the wrong wheels can create the conditions for a jackknife.

Stab Braking

For vehicles without ABS, the CDL Manual also describes a technique known as stab braking. The driver applies the brakes fully, releases them when the wheels lock, and then reapplies full braking once the wheels begin rolling again.

This is not the same as rapidly pumping the brakes.

Timing matters. Reapplying the brakes before the wheels resume rolling can prevent them from regaining traction.

Antilock Braking

Modern tractor-trailers are generally equipped with antilock braking systems, or ABS. ABS is designed to prevent wheel lockup during hard braking and help the driver maintain control.

FMCSA’s CDL guidance instructs drivers using ABS in an emergency to brake normally and maintain brake pressure. Drivers should not release and reapply the brakes simply because ABS has activated.

ABS does not necessarily shorten every stop. Its major safety advantage is helping the wheels continue rolling so the driver retains directional control.

A driver who misunderstands the system or responds incorrectly in an emergency can lose valuable stopping distance or control.

Improper Use of the Trailer Hand Valve Can Cause a Jackknife

Tractor-trailers equipped with air brakes may have a trailer hand valve—sometimes called the trolley valve—that permits the driver to apply the trailer brakes separately.

That does not mean it should be used to stop the truck during ordinary driving.

FMCSA’s CDL Manual specifically warns drivers not to use the trailer hand valve for normal driving because the trailer brakes can skid and create a jackknife danger. The manual also warns against using the hand valve for parking because air can eventually leak away and release the brakes.

The physics explains the danger.

If the trailer brakes lock while the tractor continues moving, the trailer loses directional stability. Instead of following directly behind the tractor, it can begin sliding sideways.

A driver may instinctively think that applying more braking force to the trailer will help straighten the rig. Under the wrong conditions, the opposite can happen.

When a jackknife follows emergency braking, one question our attorneys may investigate is which brakes the driver applied and how they were applied.

Engine Braking Is Different From the Service Brakes

Truck drivers may also slow a tractor-trailer through engine braking.

An engine brake—commonly referred to by the trade name “Jake Brake”—uses the engine to help slow the vehicle rather than relying entirely on the wheel-mounted service brakes. This can reduce service-brake heating and wear, particularly during long descents.

But engine braking also requires judgment.

The CDL Manual cautions that when driving on slippery roads, a driver should avoid using an engine retarder unless the manufacturer permits its use on slippery surfaces. Drive wheels can lose traction when retarders are activated on poor surfaces.

South Florida may not have icy mountain passes, but heavy rain can rapidly reduce roadway traction. A driver must adjust both speed and braking technique to conditions.

The Best Emergency Stop Often Begins Before the Emergency

A professional truck driver should not routinely need maximum emergency braking to negotiate predictable traffic.

Safe stopping begins with speed, following distance, attention, and anticipation.

A tractor-trailer requires substantial distance to stop. A driver traveling too fast for congestion, following another vehicle too closely, or failing to notice slowing traffic may leave no good braking option once danger becomes apparent.

The driver may then brake so aggressively that the combination vehicle becomes unstable.

This is especially important in Miami, where highway traffic can transition rapidly from normal speeds to stop-and-go congestion.

An insurer may describe a jackknife as the driver’s unavoidable attempt to avoid another accident. A proper investigation asks what happened before that emergency developed.

Was the truck following too closely? Was the driver distracted? Was the truck traveling too fast for traffic or weather conditions? Should the driver have begun slowing sooner?

The final seconds of a crash do not necessarily explain its true cause.

Brake Problems Can Contribute to Jackknifing

Sometimes the driver’s technique is not the only problem.

A tractor-trailer contains multiple brakes that need to operate together. Poor adjustment, defective components, inadequate maintenance, or an imbalance between tractor and trailer braking can affect how the combination vehicle responds.

Federal regulations require motor carriers to systematically inspect, repair, and maintain commercial vehicles under their control.

After a jackknife accident, evidence concerning brake condition can therefore be extremely important.

Maintenance histories, inspection records, driver-reported defects, post-crash examinations, electronic information, and expert analysis may help determine whether the truck’s braking system performed as it should have.

Cargo Can Turn a Hard Stop Into a Jackknife

Cargo also affects how a tractor-trailer responds to braking.

Improperly distributed freight can alter the trailer’s balance. Cargo that is not adequately secured can move during sudden braking, changing the trailer’s center of gravity at precisely the moment the driver is trying to maintain control.

Federal cargo securement standards require cargo to be contained, immobilized, or secured so that movement does not adversely affect the vehicle’s stability or maneuverability.

A jackknife investigation may therefore extend beyond the driver and trucking company to businesses responsible for loading, securing, maintaining, or servicing the truck.

Proving Why a Tractor-Trailer Jackknifed

The position of the vehicles after impact does not necessarily reveal why the jackknife started.

Sotolongo Law may investigate evidence such as:

• Electronic control module and vehicle data
• ABS and braking-system information
• Truck and trailer inspection records
• Brake maintenance histories
• Tire condition
• Dashcam and surveillance footage
• Electronic logging device records
• GPS information
• Cargo and loading records
• Driver training materials
• Witness statements
• Roadway evidence and photographs

In appropriate cases, accident reconstruction experts can analyze vehicle movement and physical evidence to determine how the crash developed.

Attorney Pedro P. Sotolongo has more than 20 years of personal injury legal experience and has taken on major defendants and insurance companies. His approximately five years practicing medical malpractice defense also gave him an understanding of medicine that is valuable when jackknife crashes cause traumatic brain injuries, spinal cord injuries, complex fractures, or other catastrophic harm.

Sotolongo Law combines that experience with the personal attention of a boutique Miami firm. Because We Care® means investigating the details that can make the difference in a serious truck accident case.

Frequently Asked Questions About Tractor-Trailer Jackknife Accidents in Miami

Does a jackknife mean the truck driver was negligent?

Not necessarily. A jackknife describes what the tractor-trailer did, not necessarily why it happened. Driver error, excessive speed, braking technique, mechanical defects, cargo problems, road conditions, or a combination of factors may contribute. The cause must be investigated.

Can slamming on a tractor-trailer’s brakes cause a jackknife?

Yes, particularly if wheels lock and lose traction. Proper braking technique depends in part on whether the truck has ABS and the circumstances confronting the driver. Preserving wheel traction is critical to maintaining directional control.

What is the trailer hand valve, and can it cause a jackknife?

The trailer hand valve allows the trailer brakes to be applied separately. FMCSA’s CDL Manual warns against using it during normal driving because locking the trailer brakes can cause the trailer to skid and potentially jackknife.

Can a tractor-trailer jackknife if it has anti-lock brakes?

Yes. ABS helps prevent wheel lockup and maintain control during hard braking, but it cannot eliminate every cause of a jackknife. Excessive speed, poor traction, improper steering, cargo movement, equipment problems, and other factors can still result in loss of control.

Who is responsible for a jackknife accident?

Depending on the cause, potentially responsible parties may include the truck driver, motor carrier, maintenance provider, cargo loading company, or another business. Identifying the mechanism that caused the jackknife helps determine which parties should be investigated.

Contact a Miami Tractor-Trailer Jackknife Accident Lawyer

A trucking company may call a jackknife an unavoidable emergency. Sotolongo Law looks at what happened before the trailer ever began to swing.

We investigate the driver’s speed and following distance, braking technique, ABS and brake condition, cargo loading, maintenance history, electronic evidence, and other factors that can explain why control was lost.

Pedro P. Sotolongo brings more than 20 years of personal injury experience and an understanding of the medicine involved in serious injury claims. Our boutique firm serves accident victims throughout Miami-Dade County and South Florida, including Spanish-speaking clients, and is prepared to take on large trucking companies and their insurers.

Contact Sotolongo Law today for a free consultation. You pay no attorney’s fee unless we recover compensation for you.