Final answer:
A safe following distance under ideal conditions should be no less than 3 seconds. When estimating the distance in car lengths, it depends on the speed of the vehicles involved.
Step-by-step explanation:
A safe following distance under ideal conditions should be no less than 3 seconds. This means that a driver should maintain a gap of at least 3 seconds between their car and the car in front of them. This allows for enough time to react to any sudden changes in traffic.
When estimating the distance in car lengths, it depends on the speed of the vehicles involved. As a general rule, at a speed of 60 mph, a safe following distance of 6 car lengths is recommended. However, this estimate may vary depending on factors such as the size of the cars and the road conditions.