Final answer:
A safe following distance is typically established by the '3-seconds rule,' which accommodates reaction time and necessary braking distance. In bad weather or road conditions, the distance should be increased accordingly. At urban speed limits, several car lengths between vehicles can be a general application of this rule.
Step-by-step explanation:
When you are following another vehicle, it is crucial to maintain a safe following distance. This following distance should be enough to allow you to react and stop safely if the vehicle in front of you brakes suddenly. There isn't a one-size-fits-all answer to the question, as the adequate distance varies based on speed, road conditions, and your vehicle's condition.
In general, a common rule of thumb for maintaining a safe following distance is the '3-second rule.' This means you choose a fixed point that the vehicle in front of you passes, and you should pass the same point no less than three seconds after the vehicle in front of you. This interval should be increased to 4-5 seconds in poor conditions such as rain or fog, and further extended in icy or snowy conditions.
In towns and cities with a speed limit of 60 km/h, and considering the average car length is 3.5 m, this rule would generally put a safe distance of several car lengths between you and the vehicle in front. However, driving at higher speeds or in less than ideal conditions would require a longer following distance for safety.
Understanding the reaction time and braking required, particularly as shown in physics-based vehicle dynamics, is essential for safe driving. At speeds such as 30.0 m/s, a reaction time of 0.500 s results in a considerable distance before the car comes to a full stop. Following the 3-seconds rule adjusts for these factors and provides a buffer for unforeseen events that might require you to stop suddenly.