a metre or a car length
Added; (in the US) one car length for every 10 miles-per-hour of speed.
3 seconds between you and the car in front of you.
1 CAR LINK FOR EVERY 10MPH
When driving, you should always measure your following distance in seconds. A general rule of thumb is to maintain a following distance of at least 3-4 seconds between your vehicle and the one in front of you. This distance allows you enough time to react and brake safely in case of an emergency.
7 car lengths
car lengths
distance
three truck lengths
For things such as trail riding, the recommended distance is about two horses lengths. My personal rule of thumb is that you should be able to see the back hooves of the horse in front of you.
According to the California Department of Motor Vehicles, the minimum following distance on highways is three car lengths. Anything closer is considered tailgatinging and is both unsafe and against the law. This distance is independent of time of day.
there are so many lengths in distance .The SI label for distance is meter.
perimeter
there are so many lengths in distance .The SI label for distance is meter.
In general the resonant lengths are 1/4, 3/4, 5/4
One for every 10 mph or yo can use the counting between landmarks method which does essentially the same thing since following distance would increase with speed.