Each year almost 2.2 million police-reported rear-end collisions occur. Rear-end collisions make up approximately 32% of all crashes, far exceeding other crash types.1 When a rear-end collision occurs, occupants of all vehicles involved are often injured. In heavy traffic, rear-ends often result in chain reactions as vehicles are pushed into one another.
The driver striking the other vehicle from behind is almost always found to be at fault, even if the driver in the vehicle ahead slammed on their brakes unexpectedly or cut in front of the striking vehicle at the last minute. A driver is always responsible for maintaining an adequate following distance (gap) in front of them.
An organization needs to be proactive in preventing rear-end collisions. Best practices include:
Purchasing vehicles with ADAS technology
As you replace vehicles in your fleet, consider purchasing or leasing vehicles with Advanced Driver Assistance Systems (ADAS). ADAS have proven to reduce accidents. A 2020 Insurance Institute for Highway Safety study found Forward Collision Warning (FCW) reduced front to rear collisions by 27% and FCW combined with Automatic Emergency Braking (AEB) reduced front to rear collisions by 50%.2
- Forward collision warning (FCW): This feature warns a driver that there is a possibility of a collision with an object in front of the vehicle. This feature is sometimes paired with automatic emergency braking to stop the vehicle on its own before the driver reacts
- Automatic Emergency Braking (AEB): This feature applies the brakes automatically when the vehicle senses a possibility of a collision in front of the vehicle. This is often paired with a forward collision warning system
- Adaptive Cruise Control (ACC): Similar to cruise control but this feature will maintain a constant following distance from the vehicle in front; When distance is set, the car will slow down and speed up accordingly, maintaining a proper following distance; Typically, this feature only works at higher speeds and does not have the same stopping capabilities of AEB
In some vehicles a driver has the option to turn this technology off. Organization policies should prohibit employees from doing this. Also, not all ADAS systems operate similarly. Review our article on Reducing Collisions with ADAS for more information. Educate your drivers on ADAS by sharing our bulletin Advanced Driver Assistance Systems: What Drivers Should Know.
Eliminating driver inattention and distractions
Drivers not paying attention to the roadway ahead are less likely to see traffic in front of them slowing or a vehicle cutting in front of them; increasing their risk of a rear-end collision. Methods for reducing distractions and inattention include:
- Educating drivers on distraction hazards and staying attentive to their driver duties
- Having a strong distracted driving policy
- Utilizing cell phone blockers and tracking technology to reduce cell phone use
Review our article on controlling distracted driving for more information. Educate your drivers on distracted driving with our Distracted Driving Infographic.
A primary cause of rear-end collisions is aggressive driving, specifically speeding and tailgating. Organizations should monitor drivers for these behaviors and work with drivers to reduce them. The most effective tool for identifying these behaviors is telematics. Most vehicle telematics systems include features to identify and track speeding and hard brakes events. Hard brakes often occur when following a vehicle too close.
Drivers with high speeding and hard brake scores:
- Should be counseled on the hazards of their behavior and means for improving
- Should have goals set to reduce high speeding and hard brake score
- Should have more frequent manager ride-alongs to better identify behavior and coach
For organizations without telematics, manager ride-alongs are also effective in identifying speeding and tailgating behaviors.
Training drivers on proper scanning and following distance
Scanning the roadway ahead is critical in eliminating rear-end collisions. The sooner a driver perceives a hazard the sooner they can react to it. Brake lights of the vehicle in front should not be the first indication of the need to brake. Drivers should scan ahead at least one block in city traffic and a quarter mile ahead on highways. If a driver’s eyes leave the forward roadway, to check mirrors for example, they should not be away from the forward roadway for more than 1.5 seconds, preferably less.
Drivers often rear-end the vehicle in front of them when they do not have adequate distance to perceive the hazard, react, and stop.
- Perception time/distance is a function of:
- Driver’s eyes focused on the roadway ahead
- Driver alertness: not distracted, inattentive, or fatigued
- For a focused, alert driver the average perception time is ¾ to 1.5 seconds
- Reaction time/distance is the time it takes to step on the brake, typically about ¾ of a second
- Stopping time/distance is a function of:
- Vehicle weight, including load
- Condition of brakes and tires
- Condition of roadway: surface, rain, snow, ice
- Brake lag time which is about one-half second in larger vehicles equipped with air brakes
|Total Stopping Distance @ 60 MPH and Ideal Conditions3|
|Perception Time (¾ second)||Reaction time(¾ second)||Stopping distance3||Total stopping distance|
|Average car, SUV, light truck (2020)||¾ second = 66’||¾ second = 66’||132||264’ (3 seconds)|
|Heavy Truck – post 2013||¾ second = 66’||¾ second = 66’||250||370’ (4.2 seconds)|
|Heavy Truck – Pre-2012||¾ second = 66’||¾ second = 66’||355||478’ (5.5 seconds)|
An alert driver with a well-maintained vehicle driving on dry pavement needs close to the length of a football field to stop a light vehicle, and substantially more for larger vehicles.
Most people cannot visually tell how far they are following someone. A best practice, recommended by the National Safety Council and most state driving manuals, is the seconds-counting method:
- Determine the minimum number of seconds for your vehicle (see image below); For example, three seconds for sedans, SUVs and light trucks
- When the vehicle in front passes a fixed object, such as a light post or sign, begin counting: one one-thousand, two one-thousand, three one-thousand
- If your vehicle passes the fixed object prior to three seconds, slow down and recount
The above best-practice following distances are under ideal conditions. Drivers should increase their distance further:
- During inclement weather: rain, snow, ice, fog
- When brakes and tires are worn or with heavy loads
- When they are distracted, ill or fatigued
- When being tailgated
Rear-end collisions are common at intersections. Drivers need to watch for vehicles:
- That may try to make a changing light, but brake suddenly when they decide not to
- Begin to move ahead from a stopped position when a light changes, then stop again
Preventing others from rear-ending you
To prevent other vehicles from rear-ending a vehicle. The driver should:
- Maintain a safe following distance; This allows a driver to slow gradually so they are not rear-ended by a distracted or tailgating driver
- Encourage tailgaters to change lanes and pass by slowing; They will want to get around
- Be cautious at intersections; Do not try to speed through a light and then brake expectantly
Our Preventing Rear-End Collisions Infographic addresses many of these key topics and can assist with driver education and training. Use it:
- As an awareness piece for poster boards or driver mailings
- As a training topic in driver safety meetings or toolbox talks
- As a guide for managers when conducting safety ride-alongs with drivers
1 Traffic Safety Facts 2019, Table 29: Crashes by First Harmful Event, DOT HS 813 141, National Highway Traffic Safety Administration, August 2021
2 Real-world benefits of crash avoidance technologies, Insurance Institute for Highway Safety, Highway Loss Data Institute, December 2020.
3 Consumer Reports has found the average stopping distance of Cars, SUVs and Light Trucks manufactured in 2020 to be 132 feet at 60 mph. The National Highway Transportation Administration (NHTSA) required heavy trucks manufactured prior to 2011 to stop within 355 feet at 60 mph. New NHSTA standards implemented between 2011 and 2013, depending on the size, require heavy trucks to stop within 250 feet.