Rear-end collisions rank among the most common car accidents in the United States. They can happen at any speed, from two cars tapping in heavy traffic to violent collisions between a speeding car and a stopped one. It will come as no surprise to hear that high-speed rear-end collisions frequently result in catastrophic injuries and fatalities. But even low-speed “fender-benders” can leave drivers and passengers badly hurt.
In this blog post, we dig deep into the phenomenon of rear-end collisions: what they are, how they happen, and how you can avoid them.
Rear-End Collisions Defined
In the simplest sense, a rear-end crash occurs when the front-end of one vehicle collides with the rear-end of another vehicle traveling (or pointing) in the same direction. At the moment of impact, the trailing vehicle is always traveling faster than the leading vehicle. Often, the leading vehicle is stationary.
The laws of physics dictate that, in most cases, the impact of a rear-end collision causes the trailing vehicle to slow down, while it causes the leading vehicle to speed up (when there is a huge disparity between the mass and/or velocity of the vehicles, such as in a collision between a speeding cement truck and a stopped subcompact car, the acceleration or deceleration may be minimal for one of the vehicles). For occupants of the leading vehicle, the sudden, unexpected acceleration causes many of the injuries we typically associate with rear-end collisions (discussed below). But make no mistake, the occupants of both vehicles in a rear-end collision risk suffering serious, even fatal, injuries.
Rear-End Collision Statistics
How common are rear-end collisions? Really, really common. According to the National Highway Transportation Safety Administration (NHTSA), rear-end collisions consistently account for roughly one-third (33 percent) of all reported two-vehicle accidents in the United States every year. Over the past several years, that has meant there are over 2 million reported rear-end collisions on American roads annually, according to the NHTSA. Or, to put it even more starkly, more than three rear-end collisions per minute, on average, every minute of every year. Though the most recent Crash Facts report from the Florida Department of Highway Safety and Motor Vehicles does not include rear-end collisions as a specific classification in its annual crash data, there can be little doubt these accidents are as common in the Sunshine State as anywhere else.
What is the result of all of these accidents? According to the NHTSA data, more than 2,000 rear-end collisions cause fatalities, and more than half-a-million result in injuries, every year. By any measure, that means rear-end collisions constitute a serious public health hazard on American roads.
Contributors to Rear-End Collisions
So, what causes rear end collisions? In the 2000s, the NHTSA set out to answer that question. The agency published two reports, one analyzing factors in rear-end collisions that could be addressed through more effective rear-signaling systems (i.e., better brake lights) (the 2007 Study), and the other analyzing the characteristics of drivers in rear-end collisions (the 2003 Study). Here are some highlights of what they found.
Driver Distraction Plays an Overwhelmingly Significant Role
According to the 2007 study, “approximately 87 percent of rear-end crashes in which the driver struck the lead vehicle included some form or degree of driver distraction.” Distraction makes it more likely drivers will fail to react in time to a vehicle in front of them. In fact, the study found that “[d]rivers who were glancing away from the forward roadway at the onset of lead-vehicle braking had substantially longer brake-reaction times (about 600 ms longer on average) compared to drivers whose visual focus was on the forward roadway.”
Keeping in mind that the data comes from pre-2007 research, before smart phones took over our lives, the 2007 Study also found that the types of distractions most correlated to rear-end crashes (as compared to “near-crashes” or less acute “incidents”) were dining and daydreaming. Cell phone use, at least back then, had a strong association with “near misses,” but less so with actual crashes. But there is reason to think that in the years since, with the advent of smartphones, that screen use may play an even greater role today as a distraction that causes rear-end collisions than it did back in 2007.
The Insurance Institute for Highway Safety has observed, however, that reliable data on the correlation between smartphone use and accident causation is difficult to come by, partially because cell phone use in accidents likely goes significantly underreported.
Whatever the precise mechanisms that distract us behind the wheel, however, one thing is certain: taking your eyes off of the road, for whatever reason, vastly increases your risk of getting into a rear-end collision. It likely remains the biggest contributor to these accidents.
Speed Is, Surprisingly, Less of a Factor Than You Might Think
Another intriguing and slightly counterintuitive data point noted in the 2007 Study was that as compared to “near misses” and lesser incidents, rear-end collisions “tended to occur at lower speeds.” Relatedly, roughly two-thirds of rear-end crashes observed in the study happened at traffic “junctions” (intersections, etc.) while the trailing vehicle was decelerating and the lead vehicle was stopped. Only about one-in-ten observe crashes in the 2007 Study happened while the trailing driver was traveling straight at a constant speed.
What do these statistics tell us? First, obviously, they reflect the fact that trailing drivers almost always try to avoid rear-end collisions by braking. That’s no surprise. It’s rare, although not unheard-of, for a trailing vehicle to slam into the rear of another at high speed without so much as attempting to slow down (or without having the time to do so). The other is that a large number of rear-end collisions happen in heavy traffic conditions or in situations where the driver of the trailing vehicle ought to expect the lead vehicle to slow or be stopped, but for one reason or another, doesn’t.
This may explain why people tend to think of rear-end collisions as relatively minor; they associate the speed of an accident with its severity. That makes intuitive sense, but as we discuss below, it obscures the fact that even at low speeds, rear-end collisions can cause debilitating injuries.
Driver Age and Sex Play a Role, Too
The 2003 study looked specifically at whether the age and sex of drivers had any correlation to their role in rear-end collisions. It found that overall, younger drivers, and particularly younger male drivers, were more likely to be the drivers in the trailing car than the leading car. In the general population, older drivers tend to be less likely to be involved in accidents than younger drivers, at least until they reach advanced ages.
Rear-End Collision Injuries
For the driver and passenger of the trailing car in a rear-end collision, the potential range of injuries does not differ substantially from the types of injuries they could sustain in most any other type of accident. If they wear their seat belts and have front-impact airbags, most occupants of these vehicles can hope to avoid life-threatening injuries (albeit not always), but may sustain broken bones, lacerations, back injury, and head trauma.
In contrast, occupants of the leading car in a rear-end collision face significant dangers that are somewhat particular to this kind of accident. When the impact occurs, the lead vehicle accelerates violently and unexpectedly. The safety systems that might protect these passengers in a frontal collision do not necessarily have the same effectiveness in this scenario. As their bodies suddenly accelerate forward, then decelerate as their vehicle comes to a rest, occupants of the lead car endure unnatural, injury-causing forces.
One of the most common, and misunderstood, injuries in rear-end collisions is “whiplash.” There is an unfortunate stereotype associated with this injury that sometimes leads people to think it is “made up” or not a “big deal.” Nothing could be further from the truth.
The whip that causes a whiplash injury is the whipping motion of a person’s spinal column. When the car they’re riding in suddenly accelerates, the force of that acceleration pushes passengers’ torsos forward. Their backs arch for a split-second as their head lags behind the rest of their body mass. In this instant, the force of the collision “loads” their spinal column—the vertebrae and discs—causing it to have an “S” shape as the force of the impact moves upward the way a bend in a bullwhip does from handle-to-tip. And like the tip of a whip that makes a “snap” when that bend travels the length of the whip, the head snaps back and then forward. In this motion, the soft tissue that supports the neck, muscles, and tendons, endures enormous strain, and inevitably becomes damaged.
Whiplash is a very painful injury. It can resolve on its own, but not always. Some people who sustain a whiplash injury experience secondary symptoms like headaches and chronic neck and back pain for months, or even years, afterward.
Back and Spine Injuries
Occupants of the leading car in a rear-end collision also face the risk of back and spine injuries. The same physical forces that cause whiplash can also subject the structure of the spinal column to damage, including burst discs and cracked vertebrae. Those injuries, and swelling they cause, can also lead to damage to the spinal cord. Spinal cord damage often leads to temporary or permanent paralysis.
Head Trauma/Brain Injury
Common in all car accidents, head trauma and brain injury frequently occurs in occupants of the leading car in a rear-end collision. Some of these injuries result from the occupants’ heads striking a hard surface in a car. But the nature of brain injury is such that it can occur even when a person’s head does not take a physical blow, but instead experiences a violent force, such as the force exerted in the “whipping” action associated with whiplash injuries. Brain injuries can cause significant cognitive, motor, and emotional impairment, sometimes permanent.
Though rear-end collisions result in fewer fatalities than many other types of accidents, they can pose a serious risk to passengers in the rear-most seats in the leading car. A 2017 study published by the International Research Council on the Biomechanics of Injury found that approximately three-quarters (75 percent) of all fatalities caused by rear-end collisions resulted from the collapse of the compartment of the leading vehicle. Occupants seated in the rear-most seats of these vehicles face a high risk of being crushed or injured by blunt force trauma when the passenger compartment collapses around them.
Avoiding Rear-End Collisions
Sometimes an accident finds you, despite your best efforts. But as a driver, there are steps you can take to avoid falling victim to a rear-end collision both as the trailing driver and the driver of a leading vehicle. These include:
- Eliminating distractions. As the research above reflects, avoiding distraction is the single most significant step you can take to keep yourself from being the trailing driver in a rear-end collision. Don’t text and drive, don’t eat and drive … don’t do anything but drive and drive.
- Not tailgating. Following other vehicles too closely reduces a driver’s “safety cushion” to react to sudden changes in speed by leading cars. Keeping at least a two car-length separation substantially reduces the likelihood of a rear-end collision.
- Staying away from aggressive drivers. Nothing is gained by trying to retaliate against an aggressive driver. If someone is “riding your tail,” move over and let him pass. Refusing to move over or, worse, stomping on your brakes to scare him, only invites a rear end collision in which you take the brunt of the impact.
- Exercise caution on slick road surfaces. Every driver has the obligation to drive at a safe speed for conditions. When roads are wet and slick, “safe speed” means “safe distance.” Reducing your speed to give yourself some extra stopping distance, and staying alert to anyone following you too closely in wet conditions, can help to keep you safe.
- Pick a car with driver assistance features, if you can afford them. Collision warning systems and automatic braking systems hold the promise of reducing rear-end collisions. If you can afford a car with those features, they’re likely worth the money.
If you have questions about rear end collisions, or have sustained injuries in a car accident of any kind, consult with an experienced Orlando car accident attorney today.