Following distance is the space between the back of a

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

and the front of the following vehicle in

traffic Traffic is the movement of vehicles and pedestrians along land routes. Traffic laws govern and regulate traffic, while rules of the road include traffic laws and informal rules that may have developed over time to facilitate the orderly an ...

National recommendations

Australia

In the Australian state of

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

, 3 seconds of following distance is recommended. In

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

, and

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

, 2 seconds is recommended.

Europe

In the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

, the

two-second rule 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. ...

is recommended, and in some European countries there are penalties for maintaining lower distances. In the European Union, the term "failing to keep a safe distance from the vehicle in front" is used in the Directive (EU) 2015/413 of the European Parliament and of the Council of 11 March 2015 facilitating cross-border exchange of information on road-safety-related traffic offences. In this directive "failing to keep a safe distance from the vehicle in front" means not maintaining sufficient distance from the vehicle in front, as defined in the law of the Member State of the offence.

United Kingdom

In the UK, it is recommended that 2 seconds of following distance is maintained.

United States

In the US, for safety it is recommended that 3-4 seconds of following distance is maintained. Extra time should be added for wet, rainy,

slippery Slipperiness is when a surface has a low coefficient of friction, allowing objects to glide across the surface. People walking on slippery surfaces are likely to slip or fall. A surface can for example be slippery due to it being wet, or due to ...

, foggy or other

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmo ...

situations accordingly. For heavy duty commercial vehicles it is recommended 4-6 seconds following distance for speeds under 30 mi/h (48 km/h), and 6-8 seconds following distance for speeds over 30 mi/h (48 km/h).

Rear-end collision A rear-end collision, often called rear-ending or, in the UK, a shunt, occurs when a forward-moving vehicle crashes into the back of another vehicle (often stationary) in front of it. Similarly, rear-end classification of railway accidents, ra ...

s are the number one type of

traffic collision A traffic collision, also known as a motor vehicle collision, or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other moving or stationary obstruction, such as a tree, pole or building. Tr ...

s.Rear end crashes are most common type of collisions
azdot.gov

References