A 3-minute lesson from the New Jersey course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.
Space is your time to react. Tailgating is a common cause of crashes and can set off a chain of rear-end collisions. Keep a cushion in front, add more in bad conditions, and change lanes only when you truly need to.
Know the rule
Keep plenty of space on all sides, stay in the middle of the lane, and leave enough room ahead to stop or pass safely.
At 40 mph on a wet road, the chart calls for 8 car lengths, twice the ideal distance. With the three-second rule, you would stretch your count to four seconds or more.
Check your understanding
Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.
What is the general rule of thumb for following distance based on speed?
One car length (20 ft) per 10 mph
One car length regardless of speed
Two car lengths for every 50 mph
A fixed 100 feet at any speed
Answer: One car length (20 ft) per 10 mph
The rule of thumb is to keep about one car length (roughly 20 feet) back for each 10 mph of speed.
Using the three-seconds-plus rule, how many seconds should pass between a vehicle ahead passing a fixed object and your vehicle passing that same object?
At least one second
At least three seconds
At least ten seconds
Exactly five seconds
Answer: At least three seconds
The three-seconds-plus rule requires at least three seconds between your vehicle and a fixed point the vehicle ahead has just passed.
