What are the main causes of car accidents?

There is an average of 6.7 million motor vehicle crashes every year in the United States. Thirty-three thousand of these are fatal and 1.9 million cause injuries. That’s an average of more than 18,000 collisions per day.


The National Highway Transportation Safety Administration (NHTSA) reports that drivers are the critical reason behind 94% of car accidents. Ninety-two percent of driver-related accidents – that’s roughly 86% of all accidents – involve some error on the part of one or more drivers.


Vehicle issues, environmental factors, and other “unknown critical reasons” occupy 2% of the critical accident factors in the remaining collisions. In other words, even though it is possible that defective brakes or a heavy snowstorm could cause a collision, it is much more likely that a driver’s mistake is to blame.


With this in mind, we present the top reasons car accidents happen, with emphasis on driver errors.


Distracted and Inattentive Driving

The largest category of driver-related critical reasons in the NHTSA report was “recognition error”, making up 41% of all driver-related incidents. This category refers to incidents where the driver was distracted, failed to pay adequate attention to their surroundings, or failed to properly survey the area in which they were driving.


Allowing yourself to get distracted while driving is a major mistake that can prove fatal. Distractions can refer to the driver diverting their attention to something inside their vehicle, such as a cell phone, or outside of the vehicle, such as looking at billboards.


The Centers for Disease Control and Prevention (CDC) reports that in the U.S., an average of eight people are killed in accidents involving a distracted driver every day. Some of the most common distractions include:

  • Cell phone use
  • Adjusting the radio or climate controls
  • Talking to passengers
  • Pets and young children
  • Eating
  • Applying makeup
  • Daydreaming


As the last bullet item implies, distractions don’t necessarily have to involve a specific person, object, or activity. The driver can simply have their mind on things other than the road. This is especially problematic if the driver is fatigued or feeling emotional.


Driver inattention can be caused by many things, but the consequences can always be deadly.


Speeding and Driving Too Fast for Conditions

Speed-related accidents can involve a driver who was exceeding the speed limit, but they can also include situations where the driver failed to adjust their speed for conditions. Driving too fast around a curve, for example, is a common reason for single-vehicle accidents.


Aggressive Driving

Drivers who fail to think defensively and leave little space for others on the road are much more likely to cause accidents. For example, the overwhelming majority of rear-end collisions are caused by drivers following too closely. Weaving between lanes and making illegal maneuvers are other characteristics common of aggressive drivers.


By behaving contrary to how others do on the road, aggressive drivers can involve others in accidents with little to no forewarning. These accidents also tend to be more serious compared to the average collision, with a higher likelihood of injury and disabled vehicles.


Performance Errors

While some crash situations can be avoided with careful maneuvering, only a slim number of collisions in the NHTSA study were listed with “performance error” as a critical reason. Overcorrecting from a skid and failing to avoid obstacles are examples of performance errors.


Just 11% of driver-related collisions – around 10% of all accidents – involved such an error. Instead, most collisions where outstanding driver performance could have averted the accident were caused by other errors in the first place. For example, an individual who fails to accelerate in time after merging may have misjudged a gap on the highway, or the other vehicle failed to recognize the need to slow down and avoid the oncoming vehicle.


Drowsy Driving

Drowsy driving can be as dangerous as drunk driving. Both impair your ability to focus, recognize hazards, and react to hazards in time.


Per the NHTSA, 795 road fatalities involved drowsy drivers in the year 2017.


Ignoring Traffic Signals

Running a stop sign or a red light carries automatic risk. The same applies to maneuvers like passing on a two-lane highway where there are solid double lines.


When individuals choose to ignore or fail to notice traffic signals like these, the accidents that result are often severe. Perpendicular “t-bone” collisions, for instance, often happen as a result of drivers disobeying traffic signals when entering an intersection.


Poor Vehicle Maintenance and Defects

Vehicle owners who fail to maintain their vehicle risk critical components failing at the moment they are needed most. Brakes without pads, unresponsive steering, or burnt-out headlights can all become major contributors to accidents. 


Tires are a common culprit behind vehicle-related accidents. Underinflated tires or worn down tread make it more difficult to stop, turn, or evade others in a collision scenario.


In other situations, the manufacturer of the vehicle or its parts introduced defects that caused a performance failure. One major worldwide manufacturer was ordered to pay $1.2 billion in connection with accelerator failures that caused the vehicles to accelerate uncontrollably.


While the risks of vehicle-related incidents do exist, they still only make up 2% of accident causes, according to the NHTSA.


Road Hazards, Bad Weather, and Other Environmental Factors

Like vehicle factors, environmental factors supply the critical reason for accidents in just 2% of scenarios. Even still, factors like hazards in the road, road defects, and severe weather can all contribute to accident scenarios. In many cases, aspects like poor visibility combine with driver errors to make an accident more likely than it would have been on a bright, clear day.


Of all environmental hazards, slippery roads are the riskiest. Half of all environmental-related accidents were caused by ice, loose debris, or similar situations.


Other environmental factors include glare, view obstructions, fog, heavy rain, poor road design, and hazards like debris and potholes.


Accident Causes as a Component of Injury Claims

Since the majority of accidents involve some form of human error, injury victims are often able to file a claim with the at-fault driver’s liability insurance provider. Even in situations where the accident was caused by non-human factors, any contributing human error can still allow the injury victim to recover some or all of their damages from the appropriate insurance provider.


It is crucial for accident victims to thoroughly investigate the circumstances of their accident to determine which factors played a part in causing their crash and whether one or more other parties may be ultimately responsible.