Following distance

Following distance is the space between the back of a vehicle and the front of the following vehicle in traffic.

Australia
In the Australian state of New South Wales, 3 seconds of following distance is recommended. In Queensland, Victoria, and Western Australia, 2 seconds is recommended.

Europe
In the European Union, the two-second rule is recommended, and in some European countries there are penalties for maintaining lower distances.

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, foggy or other weather 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 collisions are the number one type of traffic collisions.