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A typical example of tailgating. The first car is being followed very closely by another. Tailgating.jpg
A typical example of tailgating. The first car is being followed very closely by another.

Tailgating is the action of a driver driving behind another vehicle while not leaving sufficient distance to stop without causing a collision if the vehicle in front stops suddenly. [1]


The safe distance for following another vehicle varies depending on various factors including vehicle speed, weather, visibility and other road conditions. Some jurisdictions may require a minimal gap of a specified distance or time interval. When following heavy vehicles or in less than ideal conditions (e.g. low light or rain), a longer distance is recommended.


There can be several reasons for tailgating.

Preventing cut ins

Tailgating can occur when a vehicle attempts to prevent another vehicle on the right or left from cutting in front of them. The tailgating (or preventing) vehicle will drive as close as possible to another leading vehicle to prevent the side vehicle from cutting in. Like all forms, this practice of tailgating is illegal and attempts to force the side vehicle to slow down and get into the line of traffic behind the tailgating vehicle. This practice is very likely to evoke road rage where one vehicle is blocking and another attempts to defy the block.


Tailgating can occur because of a lack of perceived risk in so doing. Thus, it is done unconsciously or negligently, very often by people who consider themselves safe drivers and generally obey some other rules of the road. Evidence shows that more experienced drivers are more likely to be involved in rear-end collisions, possibly because they overestimate their skill and become complacent about allowing sufficient distance to avoid an accident. [2]


In its most uncivil form, it can be a case of road rage and/or intimidation. An example would be where the tailgating driver (the driver in the following vehicle) threatens damage to the leading vehicle and its occupants by driving aggressively — perhaps also with use of headlights and horn — to coerce the leading vehicle's driver into getting out of the way. The driver being tailgated might not wish to comply, especially if doing so would involve breaking the law, such as by increasing speed beyond the speed limit or changing lanes without due regard for safety.


A form of deliberate tailgating known as slipstreaming, "draft-assisted forced stop", or "draft-assisted forced auto stop" (D-FAS) is a technique used by some hypermilers to achieve greater fuel economy. D-FAS involves turning off the engine and gliding in neutral while tailgating a larger vehicle in order to take advantage of the reduced wind resistance in its immediate wake. [3] Note that this practice is extremely dangerous: while tailgating itself is inherently risky, the danger of collision is increased with D-FAS as power for power brakes can be lost after a few applications of the brake pedal and, with older cars, the pressure that causes power steering to function can be lost as well. [4]

Trailing and columns

Another instance whereby the practice of driving on a road very close to a frontward vehicle or at a close distance may occur is during an occasion whereby the drivers of the two cars are acquainted to one another. This may be due to it being a procession of motor vehicles, typically carrying or escorting a prominent person that wants to avoid interlopers. Another instance may occur where the leading vehicle is showing directions to the trailing vehicle and the trailing vehicle attempts to avoid allowing an interloping vehicle to come in between them. [5] Another sphere wherein tailgating has been observed is among drivers who are in a hurry, or other public road activity whose prerequisite is urgency or agitation. [6]

Hazards of tailgating

Tailgating can be dangerous to the tailgater, especially if they are driving closely behind a large vehicle (such as a tractor-trailer, or gas tanker). By tailgating, the driver has a shorter distance to stop, decreases the margin of error and blocks the awareness of surroundings.

If the leading vehicle decelerates suddenly (such as when encountering a traffic jam, traffic lights, avoiding pedestrians, etc.), the tailgater has a high risk of causing a rear-end collision, for which in insurance terms, he would always be held responsible. In many jurisdictions, a two second gap is recommended between any two successive moving vehicles, characterised in Britain by the slogan, "only a fool breaks the two second rule".

Fighting against tailgating

Tailgating causes most rear-end crashes in South Australia. [7] Some motorways in the United Kingdom and Australia feature certain road markings which can help resolve this problem. Consisting of an arrangement of chevrons, these remind the driver not to tailgate, and assist in the two second rule. [8] There is also signage in Britain on smart motorways when they are very congested, to say "stay in lane : congestion". This is to remind motorists that there is, in these conditions, no longer an overtaking lane, merely a number of lanes, some moving faster than others at different points in time (undertaking by inner lanes being entirely permissible in this circumstance). Those in the outermost lanes should, as usual, maintain a two second gap to the vehicle in front; as long as they do this, it is officially discouraged to change lanes. Public goods vehicle licence training in Britain states that lorries should increase the 2 second gap to the vehicle in front to 3 seconds when being tailgated, to ensure that emergency braking can be a little gentler, to compensate for the tailgating vehicle behind having eaten up its own reaction time to almost nothing.

In Germany, tailgating is punishable with a fine of up to €400. In case of gross negligence, one or more penalty points are given and the driver's license may additionally be immediately suspended for up to 3 months. [9]

Related Research Articles

Rear-end collision Traffic-collision type

A rear-end collision occurs when a vehicle crashes into the one in front of it. Common factors contributing to rear-end collisions include driver inattention or distraction, tailgating, panic stops, and reduced traction due to wet weather or worn pavement. Rear-end rail collisions occur when a train runs into the end of a preceding train.

Automotive safety Study and practice to minimize the occurrence and consequences of motor vehicle accidents

Automotive safety is the study and practice of design, construction, equipment and regulation to minimize the occurrence and consequences of traffic collisions involving motor vehicles. Road traffic safety more broadly includes roadway design.

Road traffic safety Methods and measures for reducing the risk of death and injury on roads

Road traffic safety refers to the methods and measures used to prevent road users from being killed or seriously injured. Typical road users include pedestrians, cyclists, motorists, vehicle passengers, horse riders, and passengers of on-road public transport.

Road rage Aggressive or angry behavior in road traffic

Road rage is aggressive or angry behavior exhibited by motorists. These behaviors include rude and verbal insults, physical threats or dangerous driving methods targeted toward another driver or non-drivers such as pedestrians or cyclists in an effort to intimidate or release frustration. Road rage can lead to altercations, damage to property, assaults and collisions that result in serious physical injuries or even death. Strategies include long horn honks, swerving, tailgating, brake checking, and attempting to fight.

Advanced driver-assistance systems Electronic systems that help the vehicle driver while driving or during parking

Advanced driver-assistance systems (ADAS) are groups of electronic technologies that assist drivers in driving and parking functions. Through a safe human-machine interface, ADAS increase car and road safety. ADAS use automated technology, such as sensors and cameras, to detect nearby obstacles or driver errors, and respond accordingly.

Two-second rule Rule of thumb in driving

The two-second rule is a rule of thumb by which a driver may maintain a safe trailing distance at any speed. The rule is that a driver should ideally stay at least two seconds behind any vehicle that is directly in front of his or her vehicle. It is intended for automobiles, although its general principle applies to other types of vehicles. Some areas recommend a three-second rule instead of a two-second rule to give an additional buffer.

Dooring Type of cycling accident

Dooring is the act of opening a motor vehicle door into the path of another road user. Dooring can happen when a driver has parked or stopped to exit their vehicle, or when passengers egress from cars, taxis and rideshares into the path of a cyclist in an adjacent travel lane. The width of the door zone in which this can happen varies, depending upon the model of car one is passing. The zone can be almost zero for a vehicle with sliding or gull-wing doors or much larger for a truck. In many cities across the globe, doorings are among the most common and injurious bike-vehicle incidents. Any passing vehicle may also strike and damage a negligently opened or left open door, or injure or kill the exiting motorist or passenger.

Aggressive driving is defined by the National Highway Traffic Safety Administration as the behaviour of an individual who "commits a combination of moving traffic offences so as to endanger other persons or property."

Headway is the distance between vehicles in a transit system measured in time or space. The minimum headway is the shortest such distance or time achievable by a system without a reduction in the speed of vehicles. The precise definition varies depending on the application, but it is most commonly measured as the distance from the tip of one vehicle to the tip of the next one behind it. It can be expressed as the distance between vehicles, or as time it will take for the trailing vehicle to cover that distance. A "shorter" headway signifies closer spacing between the vehicles. Airplanes operate with headways measured in hours or days, freight trains and commuter rail systems might have headways measured in parts of an hour, metro and light rail systems operate with headways on the order of 90 seconds to 5 minutes, and vehicles on a freeway can have as little as 2 seconds headway between them.

Adaptive cruise control

Adaptive cruise control (ACC) is an available cruise control advanced driver-assistance system for road vehicles that automatically adjusts the vehicle speed to maintain a safe distance from vehicles ahead. As of 2019, it is also called by 20 unique names that describe that basic functionality. This is also known as Dynamic cruise control.

Vehicle safety technology Special technology developed to ensure the safety and security of automobiles

Vehicle safety technology (VST) in the automotive industry refers to the special technology developed to ensure the safety and security of automobiles and their passengers. The term encompasses a broad umbrella of projects and devices within the automotive world. Notable examples of VST include geo-fencing capabilities, remote speed sensing, theft deterrence, damage mitigation, vehicle-to-vehicle communication, and car-to-computer communication devices which use GPS tracking.

Energy-efficient driving

Energy-efficient driving techniques are used by drivers who wish to reduce their fuel consumption, and thus maximize fuel efficiency. The use of these techniques is called "hypermiling".

Tram accident

A tram accident is any accident involving a tram. Alternatively, any accident involving a tram or a tram system may be considered a tram accident. The latter definition is more commonly used in public safety studies.

Collision avoidance system Motorcar safety system

A collision avoidance system (CAS), also known as a pre-crash system, forward collision warning system, or collision mitigation system, is an advanced driver-assistance system designed to prevent or reduce the severity of a collision. In its basic form, a forward collision warning system monitors a vehicle's speed, the speed of the vehicle in front of it, and the distance between the vehicles, so that it can provide a warning to the driver if the vehicles get too close, potentially helping to avoid a crash. Various technologies and sensors that are used include radar (all-weather) and sometimes laser (LIDAR) and cameras to detect an imminent crash. GPS sensors can detect fixed dangers such as approaching stop signs through a location database. Pedestrian detection can also be a feature of these types of systems.

Traffic collision When a vehicle collides with another object

A traffic collision, also called a motor vehicle collision, car accident or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other stationary obstruction, such as a tree, pole or building. Traffic collisions often result in injury, disability, death, and property damage as well as financial costs to both society and the individuals involved. Road transport is the most dangerous situation people deal with on a daily basis, but casualty figures from such incidents attract less media attention than other, less frequent types of tragedy.

Run-off-road collision type of single-vehicle collision

A run-off-road collision is a US term for a type of single-vehicle collision that occurs when a vehicle leaves the roadway.

Geometric design of roads Geometry of road design

The geometric design of roads is the branch of highway engineering concerned with the positioning of the physical elements of the roadway according to standards and constraints. The basic objectives in geometric design are to optimize efficiency and safety while minimizing cost and environmental damage. Geometric design also affects an emerging fifth objective called "livability," which is defined as designing roads to foster broader community goals, including providing access to employment, schools, businesses and residences, accommodate a range of travel modes such as walking, bicycling, transit, and automobiles, and minimizing fuel use, emissions and environmental damage.

Driving etiquette refers to the general courtesy rules communities expect drivers to follow. The term dates back to the early 1900s and the use of horse-drawn carriages. Driving etiquette typically involves being courteous and staying alert, which varies by vehicle, situation and location. Failure to adhere to this behavior can cause increased risk of road collisions, trauma and road rage.

In legal terminology, the assured clear distance ahead (ACDA) is the distance ahead of any terrestrial locomotive device such as a land vehicle, typically an automobile, or watercraft, within which they should be able to bring the device to a halt. It is one of the most fundamental principles governing ordinary care and the duty of care for all methods of conveyance, and is frequently used to determine if a driver is in proper control and is a nearly universally implicit consideration in vehicular accident liability. The rule is a precautionary trivial burden required to avert the great probable gravity of precious life loss and momentous damage. Satisfying the ACDA rule is necessary but not sufficient to comply with the more generalized basic speed law, and accordingly, it may be used as both a layman's criterion and judicial test for courts to use in determining if a particular speed is negligent, but not to prove it is safe. As a spatial standard of care, it also serves as required explicit and fair notice of prohibited conduct so unsafe speed laws are not void for vagueness. The concept has transcended into accident reconstruction and engineering.

The death of Elaine Herzberg was the first recorded case of a pedestrian fatality involving a self-driving car, after a collision that occurred late in the evening of March 18, 2018. Herzberg was pushing a bicycle across a four-lane road in Tempe, Arizona, United States, when she was struck by an Uber test vehicle, which was operating in self-drive mode with a human safety backup driver sitting in the driving seat. Herzberg was taken to the local hospital where she died of her injuries.


  1. "What is tailgating and why is it dangerous". 2014-03-20.
  2. rms.nsw.gov.au
  3. motherjones.com Archived 2007-01-10 at the Wayback Machine
  4. motherjones.com, King of the hypermilers-2 Archived 2007-01-09 at the Wayback Machine
  5. McManus, John (2008). Tactical Emergency Medicine. p. 223.
  6. Hennessy, Dwight (2005). Contemporary Issues in Road User Behavior and Traffic Safety. p. 74.
  7. transport.sa.gov.au - Tailgating campaign
  8. au.news.yahoo.com
  9. "Abstand und Abstandsvergehen" [Distance and Distance Offense] (in German). 2015. Retrieved 4 February 2015.