Car Accidents Caused by Auto Defects

You expect your car to work. When you press the brake pedal, the car should stop. When you turn the steering wheel, the vehicle should respond. When you flip on your headlights at night, the road ahead should become visible. These aren't luxury features. They're the basic promises every car should keep.

But sometimes, vehicles break those promises. A brake line fails on the highway. A tire suddenly loses its tread. An airbag deploys late or not at all. When these mechanical failures happen at 60 miles per hour, the results can be catastrophic.

Auto defects sit at a complicated intersection of traffic safety and product liability law. While most crashes involve driver error or road conditions, a significant portion stem from problems with the vehicles themselves. Understanding how defects cause accidents, and what your legal options are afterward, can make an enormous difference if you or someone you love has been hurt.

How Often Do Defects Actually Cause Crashes?

The National Highway Traffic Safety Administration's National Motor Vehicle Crash Causation Survey found that vehicle defects were the critical reason in about 2% of investigated police-reported crashes. That might sound small until you realize it translates to tens of thousands of crashes each year across the country.

But here's what makes that number even more significant: it's almost certainly an undercount. Many safety defects don't get spotted at crash scenes. An airbag that failed to deploy looks the same as one that was never triggered. Software malfunctions don't leave visible evidence like a blown tire does. Fire risks, sudden acceleration problems, and steering failures often get attributed to driver error in initial reports because the underlying mechanical issue isn't obvious.

NHTSA emphasizes that their defect investigation and recall system captures many safety problems that never show up in crash statistics. The real contribution of auto defects to crashes and injuries is likely much higher than official percentages suggest.

When researchers dig into which defects cause the most problems, the patterns are clear. In defect-related crashes, tire problems account for about 35% of incidents. Brake problems make up another 22%. The remaining 43% includes steering issues, suspension failures, lighting problems, and other component malfunctions.

A 2024 peer-reviewed analysis of U.S. crash data confirmed these findings, showing that brake and tire defects together represent about 65% of identified vehicle defects in crashes. The same study found something particularly troubling: headlight defects and tire tread issues were strongly associated with more severe injury outcomes. These aren't just fender benders. When these particular defects cause crashes, people get seriously hurt.

What Types of Auto Defects Lead to Accidents?

Federal crash investigators and medical researchers have identified the vehicle problems that most commonly cause or worsen accidents.

Tire failures represent the single largest category. Tread separation happens when the outer layer of a tire peels away from the inner structure, usually at highway speeds. The vehicle becomes nearly impossible to control. Blowouts, worn tread that can't grip wet roads, and sidewall failures that cause sudden air loss all appear repeatedly in crash reports. Some of these problems result from poor maintenance, but many stem from manufacturing defects or design flaws that make certain tire models prone to catastrophic failure.

Brake system defects contribute heavily to rear-end collisions and loss-of-control crashes. Hydraulic failures mean pressing the brake pedal does nothing. Worn pads or rotors beyond their service life can't generate enough friction to stop the vehicle in time. Anti-lock braking system malfunctions can cause wheels to lock up or prevent proper braking entirely. When brakes fail in traffic or on a downhill grade, drivers have almost no time to react.

Steering and suspension problems take away a driver's ability to control where the vehicle goes. Electronic power steering systems can malfunction and make the wheel impossible to turn. Tie rods can snap, causing the front wheels to point in different directions. Control arms can break, letting wheels move independently of the steering input. These failures often happen suddenly and without warning.

Lighting and visibility defects create dangers that extend beyond the defective vehicle. Headlights that are improperly aimed, too dim, or that flicker and fail leave drivers unable to see the road ahead. Brake lights that don't illuminate mean the cars behind have no warning that you're stopping. Inoperative turn signals and hazard lights prevent other drivers from anticipating your movements. Windshield wipers that quit during a rainstorm can reduce visibility to zero in seconds. Research shows that headlight defects in particular are associated with higher odds of severe injury crashes, likely because they tend to cause accidents at night when speeds are higher and help is farther away.

Airbag and restraint system failures don't usually cause crashes, but they dramatically increase injury severity when crashes happen. Non-deployment means the airbag never inflates at all, leaving occupants to strike the steering wheel or dashboard at full force. Late deployment means the airbag inflates after the occupant has already moved forward, providing no protection. Defective inflators can explode or send shrapnel into the cabin, turning a safety device into a weapon. The Takata airbag crisis affected millions of vehicles and resulted in numerous deaths and serious injuries from exploding inflators.

Electronic system and software defects are becoming more common as vehicles rely increasingly on computerized controls. Engine control failures can cause sudden loss of power in traffic. Unintended acceleration occurs when the throttle stays open despite the driver's foot being off the gas pedal. Sudden stalling can shut down a vehicle in the middle of a highway. Defective driver assistance features like automatic emergency braking that fails to engage or lane-keeping systems that steer into danger create new categories of risk.

NHTSA defines a safety defect broadly as any performance or construction problem in a motor vehicle or piece of equipment that poses an unreasonable risk to motor vehicle safety and may exist in a group of vehicles or equipment of the same type or design. This definition covers everything from obvious mechanical failures to subtle design flaws that only become apparent after thousands of vehicles are on the road.

How Does the Federal Government Track and Fix Auto Defects?

NHTSA, operating within the U.S. Department of Transportation, has statutory authority under the National Traffic and Motor Vehicle Safety Act to identify safety-related defects and require manufacturers to conduct recalls. Understanding how this system works matters because it affects whether the defect in your crash was known before your accident happened.

Defect information reaches NHTSA through multiple channels. Consumers file complaints through the agency's website or hotline. Manufacturers submit Early Warning Reporting data that includes deaths, injuries, warranty claims, property damage claims, and field reports about potential safety issues. Technical service bulletins that dealers use to fix recurring problems get reviewed. Crash investigations feed information back into the system.

NHTSA's Office of Defects Investigation screens all this data, looking for patterns that suggest a safety problem affecting multiple vehicles. When investigators spot a potential defect, they open a preliminary evaluation. This initial review examines whether the issue is widespread enough and serious enough to warrant further investigation.

If the preliminary evaluation identifies a legitimate safety concern, ODI conducts an engineering analysis. This deeper dive includes testing, expert consultation, and review of all available data. At this stage, the agency may request additional information from the manufacturer or conduct independent testing.

When NHTSA's investigation concludes that a safety defect exists, the agency can seek a formal safety defect finding. In practice, many manufacturers conduct what are called "voluntary" recalls after NHTSA opens an investigation but before a formal finding is issued. These aren't truly voluntary in most cases. They're the manufacturer's attempt to control the narrative and avoid an official government determination that their product is defective.

Once a safety defect or noncompliance with federal safety standards is established, manufacturers must notify all registered owners, dealers, and distributors. They must also provide a free remedy, which can include repair, replacement, refund, or vehicle repurchase depending on the severity of the defect and whether it can be fixed.

The defect and recall system covers vehicles, child safety seats, tires, and other equipment. Vehicle owners can and should regularly check their Vehicle Identification Number for open recalls using NHTSA's online lookup tool. Many people drive around with unfixed recall issues simply because they never received the notification or ignored the mail from the manufacturer.

Historical examples show how serious these defects can be and how long it sometimes takes for problems to be addressed. The GM ignition switch defect, which caused engines to shut off and disable airbags, was linked to hundreds of deaths and injuries before the company finally issued recalls affecting millions of vehicles. The Takata airbag crisis resulted in the largest automotive recall in history, affecting virtually every major automaker and tens of millions of vehicles.

What Does New York Law Say About Defective Vehicle Crashes?

New York law provides multiple legal theories for crash victims to pursue claims against manufacturers, dealers, and others in the chain of distribution when auto defects cause injuries.

The law recognizes three basic types of product defects. Design defects exist when the product is designed in an inherently dangerous way, even if it's manufactured exactly according to specifications. A vehicle model with a high center of gravity that makes rollovers too likely in normal driving conditions has a design defect. The problem isn't that something went wrong in building that particular vehicle. The problem is that all vehicles of that design share the dangerous characteristic.

Manufacturing defects occur when a specific vehicle or component deviates from the manufacturer's own design or quality standards. A brake assembly where the hydraulic line wasn't properly connected during assembly has a manufacturing defect. The design might be perfectly safe, but something went wrong in making that particular unit.

Marketing defects, also called failure to warn cases, arise when manufacturers don't provide adequate warnings about known risks. If an automaker knows that a particular vehicle has a tendency for the airbag to deploy late but doesn't warn buyers or issue a recall, that creates liability even if the underlying design isn't defective by other standards.

Plaintiffs can bring claims under strict products liability, negligence, and breach of implied warranty of merchantability. Most attorneys plead all three theories because they have different standards and can provide multiple paths to recovery.

In the landmark case Denny v. Ford Motor Co., New York's highest court explained how these claims relate to each other. For strict products liability design defect claims, courts use a risk-utility standard. They ask whether the product is "not reasonably safe" by weighing the benefits of the design against its risks. Could the manufacturer have designed it differently to be safer without making the product impractical or unreasonably expensive?

Breach of implied warranty claims, by contrast, focus on whether the product is fit for the ordinary purposes for which such goods are used under the Uniform Commercial Code. This is more about consumer expectations. Would a reasonable buyer expect their car's brakes to work properly? Would they expect their airbag to deploy in a front-end collision?

The Court of Appeals held that these claims are related but distinct. A design might be "not reasonably safe" under tort principles because engineers could have done better, yet still meet ordinary consumer expectations for basic functionality. Or the reverse: a design that passed the manufacturer's risk-utility analysis might still fail to perform in ways ordinary buyers would expect.

To recover on a strict liability design defect claim in New York, a plaintiff generally must show three things. First, the product as designed was not reasonably safe. Second, a feasible safer alternative design was available at the time of manufacture. Third, the defective design was a substantial factor in causing the injury. This last element is crucial because it requires proving the defect actually caused the crash or made injuries worse, not just that a defect existed somewhere in the vehicle.

These principles apply directly to auto defect crashes. A plaintiff might allege that a vehicle's electronic stability control system was inadequately designed, making rollovers too likely in emergency maneuvers. They might claim that a specific brake assembly was improperly manufactured at the factory, causing brake failure in their particular vehicle. Or they might argue that the manufacturer knew about airbag deployment problems from warranty data and crash reports but failed to warn buyers or issue a recall.

How Do You Prove a Defect Caused Your Crash?

Proving that an auto defect caused an accident requires more than testimony about what the crash felt like. It requires technical evidence that can withstand scrutiny from defense experts who will argue that driver error, poor maintenance, or road conditions caused the crash instead.

New York courts recognize what's sometimes called the "malfunction theory" of proof in product liability cases. Under this doctrine, plaintiffs don't always need to identify the precise mechanical failure if they can show three things: the vehicle didn't perform as intended, other causes can be ruled out, and the malfunction is linked to the crash. This prevents manufacturers from escaping liability simply because a crash destroyed the evidence of exactly what broke.

However, in complex automotive cases involving software, electronics, and advanced driver assistance systems, courts expect robust expert testimony and testing to establish both that a defect existed and that it specifically caused this crash. Modern vehicles have so many interconnected systems that demonstrating causation requires sophisticated analysis.

Evidence in these cases typically includes vehicle inspection reports completed by qualified mechanics or engineers who can document the defect. Event data recorder downloads provide crucial information about what the vehicle's systems were doing in the seconds before impact. Recall and technical service bulletin history can show whether the manufacturer knew about similar problems in other vehicles. NHTSA complaint and investigation records reveal whether other consumers reported the same defect. Comparison testing with similar vehicles or parts can demonstrate whether the component performed differently than it should have.

Expert witnesses reconstruct the crash sequence, showing how the defect either caused the initial loss of control or made an otherwise minor incident into a serious crash. Biomechanical experts explain how the defect affected injury severity, particularly in cases involving airbag failures or restraint system defects.

Defense attorneys predictably argue that something other than a defect caused the crash. They'll point to any evidence of driver error, even minor infractions like slightly exceeding the speed limit. They'll highlight deferred maintenance, even if the maintenance issue was unrelated to the defect that caused the crash. They'll emphasize poor weather or road conditions, arguing these were the real cause.

Plaintiffs respond by demonstrating compliance with all recommended maintenance schedules. They use the event data recorder and other electronic evidence to show they were driving reasonably. They present expert reconstructions that isolate the defect as the cause, showing that the crash wouldn't have happened or would have been much less severe without the mechanical failure.

Consider a hypothetical example:

A driver is traveling on the highway when their brakes suddenly fail. The car can't slow down approaching stopped traffic. A rear-end collision results in serious injuries. The driver's attorney will need to establish several points:

• First, the brakes actually failed rather than the driver simply not pressing the pedal in time. Event data recorder information showing no brake pedal application despite the approaching collision supports this.
• Second, the failure resulted from a defect rather than poor maintenance. Inspection records showing recent brake service and proper maintenance support this.
• Third, the brake failure actually caused this crash. Expert testimony explaining that properly functioning brakes would have stopped the vehicle in time establishes causation.
• Fourth, the failure resulted from either a design defect affecting all similar vehicles or a manufacturing defect in this particular brake system. Testing of the failed components and comparison to other vehicles determines which theory applies.

How Does Fault Get Divided When Defects Are Involved?

Auto defect cases in New York operate under the state's comparative negligence framework, which can lead to complex apportionment of fault among multiple parties.

New York follows pure comparative negligence. This means a plaintiff's damages are reduced by their percentage of fault, but they're not barred from recovery even if they were partially at fault for the accident. If a jury finds that defective brakes caused a crash but the driver was also speeding, the driver's recovery is reduced by their fault percentage but not eliminated.

This matters enormously in defect cases because manufacturers will always look for ways to blame the crash victim. They'll argue the victim didn't maintain the vehicle properly, ignored recall notices, modified the vehicle, or drove negligently. Even if these arguments are partially successful, under New York law the victim can still recover damages proportional to the manufacturer's share of responsibility.

Multiple defendants often appear in defect cases. The vehicle manufacturer designed and built the car. A separate component manufacturer may have made the defective part. The dealership may have installed or serviced the component. A repair shop may have worked on the system before the crash. Each potentially bears some share of liability depending on their role in creating or failing to fix the defect.

New York courts allow recovery not only for drivers and passengers injured in the defective vehicle, but also for bystanders struck by a vehicle whose defect caused it to veer out of control. Product liability rules protect anyone foreseeably endangered by a defective product, not just the purchaser.

The interaction between comparative negligence and strict liability means that even if a crash victim made mistakes, a manufacturer whose defect turned a survivable incident into a catastrophe remains liable for the additional harm the defect caused. A driver might have been following too closely, but if defective brakes that should have allowed a controlled stop instead led to a violent collision, the manufacturer pays for the difference between the minor injuries that would have resulted from a normal stop and the severe injuries that resulted from total brake failure.

How Do Defects Change Injury Outcomes?

Medical research provides important context for understanding why mechanical defects matter so much to injury severity, even in crashes that might seem survivable.

The 2024 injury severity study of defect-related crashes found that certain defects are associated with significantly higher odds of major injuries. Headlight problems and worn tire tread particularly correlated with severe injuries, likely because these defects tend to manifest in conditions where speeds are higher or visibility is already compromised. A headlight failure at 30 mph in daylight might be inconvenient. The same failure at 65 mph on a dark rural highway can be deadly.

Interestingly, crashes involving brake defects in the study were more often associated with minor injuries on average, probably because many occurred at lower speeds in traffic situations like rear-end collisions. But this average masks the reality that brake defects can cause catastrophic harm when they occur at highway speeds, on steep grades, or in situations where the driver has no escape route.

Public health research consistently links failures of restraint systems and airbags with elevated risks of traumatic brain injury, spinal cord injury, and chest trauma. These safety systems exist specifically to manage crash forces and protect occupants during impacts. When they fail due to defects, injuries that should have been prevented or minimized become life-altering or fatal.

The chain of causation can be subtle but devastating. A tire tread separation causes loss of control. The vehicle leaves the roadway and strikes a tree. The impact should have been survivable with proper airbag deployment. But the airbag fails to deploy due to a defect in the crash sensor. The driver suffers a severe traumatic brain injury that wouldn't have occurred if the airbag had worked. The tire defect initiated the crash, but the airbag defect determined the injury outcome. Both manufacturers potentially bear liability.

This is why even small mechanical failures can dramatically change crash outcomes. Modern vehicles incorporate numerous safety systems that work together to protect occupants. When one system fails, it can compromise the effectiveness of others or eliminate protection entirely. A defect in the electronic stability control might cause a rollover that wouldn't otherwise occur. A defect in the side curtain airbags means occupants aren't protected during that rollover. A defect in the door latches means doors pop open during the rollover, ejecting occupants. Each defect multiplies the risk created by the others.

What Should You Do If You Suspect a Defect Caused Your Crash?

If you've been in a crash and suspect a vehicle defect played a role, certain steps can preserve your legal options.

Seek medical attention immediately, even if injuries seem minor. Adrenaline masks pain and some serious injuries don't produce symptoms right away. Medical records created close to the crash provide crucial documentation.

If possible, photograph the vehicle before repairs begin. Take pictures of any damaged components, dashboard warning lights, and the position of controls. Document tire tread depth, brake pad wear, and any visible mechanical damage. These photographs can't be recreated later.

Save all maintenance records for the vehicle. These show you maintained the car properly and can refute claims that poor maintenance caused the defect. Keep recall notices and correspondence with the manufacturer or dealer about any previous problems with the vehicle.

Report the crash to NHTSA through their website or hotline. These reports feed into the defect investigation system and create an independent record of your complaint. Your report might be the one that tips investigators to a broader safety problem.

Don't let the insurance company pressure you into quick repairs or disposal of the vehicle before it can be inspected. Once repairs begin, evidence of the defect may be destroyed. Some insurance adjusters will push for immediate repairs to minimize storage fees, but preserving evidence is more important than saving storage costs.

Consult with an attorney experienced in product liability and auto defect cases before making decisions about how to proceed. These cases involve complex technical and legal issues. An attorney can arrange for proper vehicle inspection by qualified experts, obtain event data recorder downloads before the data is lost, and identify all potentially liable parties.

Be aware that product liability claims have different statutes of limitations than ordinary negligence claims. In New York, you generally have three years from the date of injury to file a product liability lawsuit, but various factors can shorten or toll this period. Waiting too long can forfeit your rights entirely.

Get a Free Case Review

Talk to our experienced car accident lawyers and know all your legal options for recovery in a free, no-obligation consultation.

Contact Us

Summing It Up

Auto defects occupy a strange space in our thinking about car crashes. We know intellectually that mechanical things break. We accept that tires wear out, brakes need replacement, and parts fail. But we operate under an implicit assumption that our vehicles will work when we need them to, that the brakes will stop us, that the airbag will deploy, that the steering will respond.

When that assumption proves false, when a defect causes or worsens a crash, the consequences cascade through victims' lives. Injuries that should have been prevented become permanent disabilities. Crashes that should have been survivable become fatal. Victims face medical bills, lost wages, and changed futures because a manufacturer cut corners on design or quality control.

New York law provides meaningful remedies, but pursuing them requires understanding both the technical reality of how vehicles fail and the legal framework for holding manufacturers accountable. Vehicle defects cause tens of thousands of crashes each year. Many more victims suffer worsened injuries because safety systems that should have protected them didn't work as designed.

If a defect played any role in your crash or injuries, you deserve answers about what failed, why it failed, and who bears responsibility. The law recognizes that even if you made mistakes, manufacturers who put defective vehicles on the road must answer for the harm those defects cause. You don't have to prove the manufacturer was the only cause. You just have to prove the defect was a substantial factor in causing your injuries.

The complexity of modern vehicles makes these cases technically demanding. The stakes for manufacturers make them legally challenging. But the law exists to protect people harmed by defective products, and that includes vehicles that break their basic promises about safety and performance.

If you were injured because of a defective part or a defective automobile, reach out to the Porter Law Group today. Fill out our online form for a free consultation and know your options. You can also call 833-PORTER9 or email info@porterlawteam.com to get started.