Tailgating is the act of driving on a road too close to the vehicle in front, such that the distance between the two vehicles does not guarantee that stopping to avoid collision is possible.
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.