One car length for every ten miles per hour is a rule, two seconds is another rule, but in the rain, 3-5 seconds. Pick out a stationary object on the road as you drive. When the car ahead of you passes that object, start counting; you shouldn't reach that object until five seconds have passed. A good rule is you should feel comfortable about having a smooth stop if that car suddenly brakes hard. If this is for a motor vehicle test, I'd say 3-5 seconds.
it is recommende to keep a gap of at least two seconds behind the car in front of you so the distance varies with the speed
Six car lengths is a good distance.
A safe following distance between cars when driving is typically recommended to be at least 3-4 car lengths.
Safe distance is 2 seconds, or 4 car lengths. More if snow is on the ground or its raining.
One car length for every 10 miles per hour.
The distance between two cars while driving should be at least 2–3 seconds of following distance under normal conditions. This allows enough time to react to any sudden stops or changes in traffic flow. It is important to increase the following distance in adverse weather conditions or when driving at higher speeds.
I always heard of the two second rule but I am not sure if that is law.
1m
one car length per 10 miles per hour
A safe distance, there is no defined limits of this type as driving near parked cars is situational (at best).
One car length for every 10 miles per hour of speed.
Know your distance between cars, fire hydrants and railroad crossing. These are the most over looked.