Final answer:
Defensive driving experts often suggest maintaining a following distance of at least 3 seconds under good conditions, and increasing it as conditions worsen. Looking 12 to 15 seconds ahead is recommended to spot hazards and adjust driving.
Step-by-step explanation:
The question regarding how many seconds ahead a motorist should look and how long it should take to reach an object does not have a single correct response since it varies with driving conditions and speed. However, a commonly recommended practice by defensive driving experts is to maintain at least a 3-second following distance from the car in front under good conditions, which can be measured by choosing a stationary object and counting the time it takes for you to reach it after the car in front of you passes it. This distance should be increased to 4 or 5 seconds under less ideal driving conditions. Looking 12 to 15 seconds ahead allows the driver to be aware of upcoming hazards and have sufficient time to react to the traffic flow.